Healthcare

The New Zealand General Practice Podcast

opotikigp family medicine, general practice, Healthcare , , , ,

Clinical Snippets June 2025

1. NOS and Nangs

A recent case I have looked at involved a young adult female presenting with slowly progressive bilateral lower limb sensory then motor changes eventually diagnosed as NOS-induced myelopathy (once her NO2 abuse was disclosed). A case series on the condition was published last year in NZMJ but there is an excellent RACGP article from 2021 examining the issue that includes the following points:

(i) Recreational NO2 use is widespread with ease of access and the common misperception of a ‘safe high’ contributing to abuse of the drug. The gas is cheap and easily accessible in the form of small metallic canisters (or larger decorated canisters) used as a propellant in whipped cream dispensers. Canisters, colloquially called ‘nangs’ or ‘whippits’, can be purchased in bulk from convenience stores or online suppliers, ostensibly for making whipped cream. The gas is discharged into a balloon using a small mechanical ‘cracker’ and then inhaled. The fleeting ‘high’ lasts only for a minute or so, and it is therefore common for people to use tens to hundreds of canisters in a session.

(ii) Nitrous oxide exerts its neurotoxicity through vitamin B12 inactivation, which disrupts myelin sheath maintenance, leading to peripheral and central nervous system demyelination. Importantly, patients often present with non-specific sensorimotor signs and symptoms with normal serum vitamin B12 levels. Early recognition and treatment are crucial to limit long-term neurological sequelae.  Patients who are predisposed to Vitamin B12 deficiency for other reasons (eg malabsorption) may be more susceptible to the neurotoxic effects of nitrous oxide abuse. While neurological manifestations can occur in isolation, other features typical of chronic vitamin B12 deficiency may also be present such as glossitis and clinical features of anaemia. Neuropsychiatric presentations including psychosis have also been reported.  

(iii) Patients can present with varying degrees of upper and lower motor neurone involvement resulting from the combination of a myelopathy and peripheral neuropathy, respectively. Spinal cord involvement (most commonly reported) manifests as spasticity, pyramidal pattern weakness and dorsal column sensory loss. Peripheral nerve involvement results in length-dependent large and small fibre sensory loss (often painful) and symmetrical distal weakness. Some patients develop visual disturbance because of optic neuropathy. The result is a combination of spasticity, sensory ataxia and weakness. The differential diagnosis of such a presentation is quite broad (discussed in detail in the RACGP article) but the earlier NO2 neurotoxicity is recognised and treatment commenced, the better the chance of full recovery.

(iv) In most cases of nitrous oxide toxicity, haemoglobin and MCV are normal, although in chronic abuse, a macrocytic anaemia may be present alongside a megaloblastic blood film. Importantly, while the serum B12 level may be low, it is often within the normal range, which can be falsely reassuring. This is because nitrous oxide causes inactivation of vitamin B12 rather than true deficiency. Therefore, if there is clinical suspicion, it is critical to check homocysteine and methylmalonic acid (MMA) levels, which are functional indicators of vitamin B12 status and are elevated in >98% of patients with clinical deficiency.  Elevated MMA is specific for vitamin B12 deficiency, whereas homocysteine may also be elevated in patients with folate deficiency, renal failure and hypothyroidism.  

(v) Treatment involves cessation of nitrous oxide and immediate administration of hydroxocobalamin (B12). Current guidelines suggest intramuscular, rather than oral, treatment, at a dose of 1mg on alternating days for two weeks, although it is reasonable to continue with this replacement schedule while there is ongoing neurological improvement. Homocysteine and MMA levels recover rapidly with treatment and can be used as a marker of biochemical treatment response; however, clinical response always lags behind. B12 maintenance therapy is needed if an additional secondary cause for B12 deficiency is found. Folate deficiency should be corrected alongside vitamin B12. Some online ‘nang’ forums suggest oral vitamin B12 supplementation as ‘prophylaxis’ while using nitrous oxide; however, there is debate over how efficacious this might be in preventing neurotoxicity.

(vi) Medsafe notes in September 2024 that nitrous oxide, when intended for use for a therapeutic purpose and presented for use as such, is a medicine under the Medicines Act 1981. However, if it is not intended for a therapeutic purpose and is intended for use or is used as a recreational drug, it is a psychoactive substance under the Psychoactive Substances Act 2013. Supply of a psychoactive substance for the primary purpose of inducing a psychoactive effect, without a product approval and a licence issued under the Psychoactive Substances Act 2013 is prohibited. There are serious penalties, including substantial fines and imprisonment should a successful prosecution be taken against an organisation or individual supplying nitrous oxide for this purpose.

(vii) RNZ reports an interview in September last year with [xx] who owns a convenience and vape store in the Auckland CBD, who said the store sells nitrous oxide canisters to those who do not appear to be using them for recreational use. They sell them in boxes of 10 for $20. “If they call it nangs, it means they’re using it for other ways. But, if some people come in and ask us for cream chargers, first, we ask for ID if they are over 18, and we ask the purpose for use.  “If they say for cooking or something, we will sell it,” he said.  It seems similarly easy to buy small and large canisters online.   

2.  Updated rheumatic fever guidelines

Just a reminder that the Aotearoa New Zealand Rheumatic fever guidelines were updated mid last year with a handy Summary guide for clinicians  containing key messages and changes in clinical guidance, along with tables and algorithms summarising recommendations for diagnosis and management of acute rheumatic fever and rheumatic heart disease. Some key points include:

  • Modifications have been made to the assessment of ARF risk in a person with a sore throat with higher-risk definition now Māori or Pacific peoples who are 3–35 years (with emphasis on those 4–19 years) OR Personal or family history of ARF/RHD.
  • Rapid antigen diagnostic tests (RADT) are not recommended in Aotearoa.
  • Phenoxymethylpenicillin dosing has been simplified to twice daily dosing (15mg/kg (maximum 500mg/dose) twice daily).
  • Recommendations have been added for the single dose administration of IM benzathine penicillin as an option (see algorithm for doses).
  • Roxithromycin has been removed for people with documented penicillin allergy, while erythromycin remains available for this indication (20mg/kg/dose two times daily – max 1.6g daily). 
  • All oral treatments are for 10 days unless a swab result (if taken) returns a negative result
  • Streptococcal antibody titres to support the diagnosis of ARF have been revised reference intervals updated.  Other changes aimed at increasing detection of acute rheumatic fever and accuracy of diagnosis are discussed and I recommend reviewing at least the summary document.

3.  Antipsychotic audit

Best Practice Bulletin Issue 122 announces release of a new clinical audit tool on antipsychotic prescribing in older people. 

The audit identifies patients aged 65 years and over who are taking an antipsychotic medicine to assess whether there is an ongoing indication for treatment, whether non-pharmacological interventions have been discussed and if treatment has recently been reviewed. There are links to the 2020 BPAC publication on appropriate prescribing of antipsychotics in this age group.

This is an area where I see complaints not infrequently with issues often relating to lack of information provided at the time of prescribing regarding the nature of the medication, off-label prescribing (if relevant eg quetiapine for insomnia) and potential risks.  New Zealand Formulary carries a blue-box warning noted below for quetiapine:

4.  ACC Resources

The ACC monthly provider update last month included links to some handy resources:

(i)  ACC National Sport Concussion Management guidelines that includes a one page Graduated return to education/work & sport protocol outlining the various recovery stages and useful as an ‘official’ guide for patients/parents/coaches wanting to ‘ bend the rules’.  At this point I’ll put in another plug for the Brain Injury Screening Tool which can be completed on line and downloaded as a PDF and is great for monitoring recovery from a TBI.  

(ii)  The update notes BPAC have recently published a comprehensive guide and B-Quick summary to support primary care clinicians in navigating the ACC recovery at work process, including considerations when issuing medical certificates. BPAC have also developed a case study and quiz with interactive feedback for this topic. The quiz follows two different cases through the recovery at work framework.

(iii) An ACC-produced downloadable resource for patients on understanding fit for selected work medical certificates is available for medical and nurse practitioners to support their kiritaki (clients). It explains the benefits to them, why they’re not ‘fully unfit’, and how to apply for weekly compensation and other supports.

(iv)   ACC Provider Videos are available. These short videos cover various aspects of working with ACC including topics such as gradual process injury, appropriate use of READ codes, treatment injury, updating or adding a diagnosis for cover etc. 

5. June Prescriber Update Highlights

The June 2025 Prescriber Update includes the following brief updates:

(i)  Patients with BRASH syndrome (bradycardia, renal failure,AV node blockade, shock, hyperkalaemia)  may present with a range of symptoms from asymptomatic bradycardia to multiorgan failure. The main differential diagnosis to consider is isolated hyperkalaemia. BRASH syndrome involves the synergistic effects of atrioventricular (AV) node blockers with hyperkalaemia, causing profound bradycardia.  Triggers include hypovolaemia due to illness and starting or increasing the dose of medicines such as AV blockers (primarily beta-blockers and calcium channel blockers). Medicines that cause acute kidney injury, hyperkalaemia or reduced cardiac output may also contribute to the development of BRASH syndrome (eg ACEs, ARBs, spironolactone).  Healthcare professionals should consider BRASH syndrome in patients taking AV blocking medicines who present with signs of bradycardia and/or hyperkalaemia, even if they seem relatively well.

(ii) Peripheral neuropathy is a known side effect of vitamin B6. Vitamin B6 is commonly present in dietary supplements such as vitamin B complexes and multivitamin and mineral preparations, often in combination with magnesium or zinc. Vitamin B6 is also an ingredient in some medicines. In patients with signs and symptoms of peripheral neuropathy, remember to ask about supplement use.

(iii)  Hepatic reactions can occur with both short-term and long-term nitrofurantoin use. Use nitrofurantoin with caution in patients with hepatic dysfunction. Nitrofurantoin is contraindicated in patients with previous history of nitrofurantoin-related hepatotoxicity. Educate patients and caregivers about the signs and symptoms of hepatic dysfunction, such as yellowing of the skin or eyes, upper right abdominal pain, dark urine and pale or grey-coloured stools, itching or joint pain and swelling, and advise them to seek immediate medical advice if they occur.

6.  Deceased patient notes

  • A recent NZ Doctor article discussed actions you should take if you get a request for a deceased person’s medical information.   Rule 11 of the Health Information Privacy Code generally prohibits a health agency from disclosing a person’s health information and it still applies to a deceased individual’s information. This means to disclose health information about a person who has died, an agency must be satisfied that one of the exceptions in rule 11 applies.
  • Rule 11(5) gives the deceased patient’s representative (executor or administrator) the legal right to request access to their health information. This is treated as if the request was made under principle 6 – access to personal information by the person whose information it is. Someone who had an enduring power of attorney while the patient was alive is not always the executor or administrator of their estate once they’ve died, so it’s important to check who the representative is once the patient has died.
  • If someone who is not the legal representative makes a request, an agency may choose to disclose the information if it reasonably believes one of the other exceptions applies. However, this only allows an agency to decide whether it wishes to disclose the information. It is not required to and couldn’t be forced to exercise its discretion either way. Also, Section 53(b)(ii) of the Privacy Act permits an agency to withhold personal information if releasing it would involve the unwarranted disclosure of the affairs of another individual or a deceased individual,
  • Rule 11(2)(b) allows a health agency to disclose information to a near relative of the deceased person in accordance with recognised professional practice. This exception requires the agency to consider whether the disclosure contradicts the patient’s or their representative’s wishes. It will ultimately be up to the agency holding the information to determine whether this applies.
  • The bottom line is that you are probably better to err on the side of caution and seek medicolegal advice if the situation is unclear.    

7. Odd things

(i) Issue 251 of GP Research review discusses  a case study published in Ear, Nose & Throat Journal of a patient who reported temporary vertigo and nausea following head movements, after he began using earbuds during exercise and while driving.  During an acute vertigo episode, he returned a positive Dix Hallpike test, and physical examination indicated posterior semicircular canal benign paroxysmal positional vertigo in the right ear. After the patient stopped using earbuds, he experienced complete resolution of dizziness, tinnitus and tingling within the ear. The patient then began using bone-conduction headphones, and after 6 months, he had not experienced any subsequent dizziness or other symptoms. It was felt he suffered from earbuds induced benign paroxysmal positional vertigo and it may be worth enquiring about earbud use in patients presenting with BPPV symptoms.

(ii) Medscape family Medicine reported on research suggesting  saffron may help treat sexual dysfunction related to selective serotonin reuptake inhibitors (SSRIs). Results of a preliminary new review found saffron, a spice derived from the flower of Crocus sativus, commonly known as the “saffron crocus,” reduced SSRI-related erectile dysfunction in men and boosted arousal in women.  After conducting a literature search, the researchers included five studies in their review, all conducted in Iran between 2009 and 2017. It is noted that Iran is the world’s leading exporter of saffron, producing about 90% of the global supply. It has long been used there both in cuisine and for medicinal purposes. Four of the studies were randomized controlled trials (RCTs), while the fifth was a single-group clinical trial. The various studies used doses ranging from 5-30mg saffron daily with the author noting doses above 5g daily are considered unsafe.  Saffron capsules are readily available in does from 13.5 – 88.5mg

The New Zealand General Practice Podcast

opotikigp family medicine, general practice, Healthcare , , , , ,

Clinical Snippets May 2025

Clinical Snippets May 2025

1. Fitness to Drive

(i)  NZ Transport Agency Waka Kotahi (NZTA) wants to increase awareness that senior drivers can renew their licence as early as six months before it expires. Renewing early won’t affect the new driver licence expiry date. Senior drivers are required to renew their driver licence at age 75, 80 and every two years after that, and need to present a medical certificate when renewing.

(ii)  Just a reminder to make sure you are aware of the latest issue of Medical aspects of fitness to drive –  A guide for health practitioners published six months ago.  There is a helpful MPS discussion document accessible via a link on Health Pathways (Medical Protection – Is My Patient Fit to Drive) which discusses the medicolegal aspects of some of the changes in the new edition, particularly regarding expectations in relation to warning patients of conditions or medications that might affect their driving.  The relevant clause in the guide is When seeing a patient or prescribing medication, consider whether the patient drives and whether you should give them advice about the effect their medication or condition may have on their ability to drive. If you give advice about driving restrictions, record this in the notes and give the patient written advice, particularly if the consultation relates to driving certification. 

(iii)  The MPS document also notes that the new guide helpfully clarifies the difference between an occupational therapist driving assessment and an on-road safety test and points out that the on-road safety test is not a medical assessment and should not be used if you have concerns around the patient’s physical and cognitive ability to drive a vehicle safely. There is a useful chart in the guide which lays out the difference between these two assessments.

2.  Drug driving 

(i) In 2023, the Land Transport (Drug Driving) Amendment Act (LTAA) 2022 came into effect which lists 25 prescription medicines and illicit drugs (defined in the Act as Schedule 5) with highest risk for impairing driving. The Act also lists blood concentration levels for Schedule 5 substances that indicate impairment for offences related to drug driving. If a driver tests positive for a Schedule 5 substance, a medical defence is available to them if they have a valid prescription for that medicine and were taking it as prescribed.

(ii) An article published in the New Zealand Medical Journal (NZMJ) reviews the implications of the law change for prescribers and provides practical advice when discussing this situation with patients. The authors note that there is currently no guidance from regulatory bodies on this topic and that “… this article provides an outline of a what a reasonable prescriber might do. If adhered to, this advice [the NZMJ article] should provide a defensible position should a prescriber become the subject of an investigation or complaint related to the LTAA.”

(iii) The article includes some practical tips for prescribers, summarized in a recent best practice Bulletin (122) as:

  • If a patient is prescribed a Section 5 medicine that could impair driving, it is best practice to inform them of this and the LTAA legislation
  • Advise patients that their medical defence may be invalidated if they consume alcohol and drive while also taking prescribed Schedule 5 medicines
  • Consider whether referral for an occupational therapist driving assessment is appropriate if there is particular concern about a patient driving while taking their prescribed Schedule 5 medicine. Clinicians do not have to carry out driving suitability tests for patients during a consultation, e.g. reaction time testing.
  • There is no clinical value in measuring blood concentration levels of Schedule 5 prescription medicines to assess a patient’s suitability to drive
  • It is good prescribing practice to document driving instructions in the patient’s clinical notes and also on the prescription so the pharmacist can remind patients of the advice
  • Patients should be advised not to drive if they feel sedated or feel like their driving is affected
  • Sedation is a subjective feeling. Advise patients that their driving ability may still be affected even if the sedative feeling has worn off.
  • Patients taking stable doses of one Schedule 5 prescription medicine and no other psychoactive substances should be informed of the LTAA legislation, but in most circumstances a clinician would not tell these patients that they could not drive
  • Patients with complex prescribing (e.g. taking multiple Schedule 5 medicines or taking other psychoactive substances) should have their suitability to drive discussed with a colleague, e.g. peer group, mental health pharmacist. In some circumstances, patients may need to be advised not to drive, or referral for an occupational therapist driving assessment may be appropriate.
  • A practical rule for patients taking Schedule 5 prescription medicines short-term or as needed is to wait until at least two half-lives have passed before driving, i.e. ~75% of the medicine has been cleared.  For example, codeine has a half-life of 3 – 4 hours, therefore, as part of good prescribing practices, patients may be advised to wait at least eight hours after taking the medicine before driving (For approximate half-lives of commonly prescribed Schedule 5 medicines, see Appendix Table 1 in the NZMJ article)
  • A longer stand-down period before driving (i.e. four half-lives) is appropriate in certain situations, such as patients with renal or hepatic impairment, who are older, who are taking higher than standard doses or multiple psychoactive medicines, patients who take ”as needed” medicines more than two to three times weekly (driving may be more impaired because they do not develop tolerance as much as someone who takes the medicine daily) or any other situation identified by the prescriber

3.  Shingles vaccine and dementia

(i) When Zostavax was rolled out in the US in 2006, several studies found lower rates of dementia in people who received the shots although most studies compared vaccinated with unvaccinated cohorts, a design prone to selection bias, including healthy-vaccinee bias, meaning that individuals who decide to get vaccinated are generally healthier than those who choose not to.  The latest study published in Nature last month took advantage of a vaccination rollout that was undertaken in Wales more than a decade ago. Public health policy dictated that from 1 September 2013, people born on or after 2 September 1933 became eligible for the Zostavax shot, while those who were older missed out. Groups either side of the cutoff date were compared  (percentage of adults who received the vaccine increased from 0.01% among patients who were merely 1 week too old to be eligible, to 47.2% among those who were just 1 week younger).  Receiving the zoster vaccine reduced the probability of a new dementia diagnosis over a follow-up period of 7 years by 3.5 percentage points corresponding to a 20.0%  relative reduction. This protective effect was stronger among women than men.

(iii)  Possibly of more interest to us with the availability of Shingrix is a study published last year in  Nature Medicine that involved review of the health records of more than 200,000 US citizens vaccinated for shingles, about half of whom received Shingrix rather than Zostavax. Over the next six years, the risk of dementia was 17% lower in those who received Shingrix compared with Zostavax.  For those who went on to develop dementia, that amounts to an extra 164 days, or nearly six months, lived without the condition. The effect was stronger in women, at 22%, than in men at 13%.

(iv) It is unclear how shingles vaccines might protect against dementia, but one theory is that they reduce inflammation in the nervous system by preventing reactivation of the virus. Another theory is that the vaccines induce broader changes in the immune system that are protective. These wider effects are seen more often in women, potentially explaining the sex differences in the studies.

4. Denosumab for osteoporosis

(i) Pharmac has widened access to denosumab for osteoporosis and people with high calcium levels associated with cancer.  The Prolia brand is available for osteoporosis treatment as a subcutaneous injection given once every six months.  It is available on special authority from any relevant practitioner  for patients with established osteoporosis (see SA form for criteria) and:

  • Bisphosphonates are contraindicated because the patient’s creatinine clearance or eGFR is less than 35 mL/min; OR
  • The patient has experienced at least two symptomatic new fractures or a BMD loss greater than 2% per year, after at least 12 months’ continuous therapy with a funded antiresorptive agent; OR
  • Bisphosphonates result in intolerable side effects; OR
  • Intravenous bisphosphonates cannot be administered due to logistical or technical reasons

(ii) Health Pathways notes that any delay in subsequent doses, or cessation of denosumab can result in rapid loss of bone mass, roughly equivalent to what was gained on the medication. This results in an increased fracture risk and is an important consideration before starting treatment – essentially you need to have a backup plan in the event of need for cessation of denosumab.  The current recommendations is that you seek endocrinology advice before prescribing if considering using denosumab .

(iii) ONZ & FLNNZ  have published a very handy Summary of Denosumab Recommendations which covers all aspects of use of the medication and is worth downloading for rapid reference.  The advice reiterates that patients must understand and commit to ongoing injections every six months to avoid rapid bone loss and ‘rebound’ vertebral fractures. Denosumab should not be stopped abruptly due to the risk of rebound fractures. If discontinuation is necessary, a bisphosphonate (e.g., IV zoledronate) should be initiated six months after the last dose to prevent rapid bone loss.

5.  Practical hints

(i) Treating bacterial vaginosis (BV) as an STI could improve outcomes.   An Australian study published in NEJM and available as a 1-page summary document looked at 164 adult heterosexual couples who were in a monogamous relationship and where the female partner had BV.   The women were treated with standard first—line antimicrobials and half the male partners were treated concurrently (oral metronidazole and 2% clindamycin cream to the penile skin) while the other half received no treatment.   The primary efficacy outcome was recurrence of BV within 12 weeks.  The trial was stopped early when clear inferiority of treating only the female partner was demonstrated on interim analysis.  The recurrence rate with  both partners treated was 1.6 per person/year compared with 4.2 per person/year when only the female was treated.  No suitable topical clindamycin cream seems to be available in NZ although a 2% vaginal cream is awaiting a decision re funding from Pharmac.   Current NZ guidelines do not yet reflect these research findings. 

(ii)  Tools for Practice #388  looked at the use of topical tranexamic acid for nose bleeds.  Tranexamic acid intravenous solution applied to a cotton pledget increases the proportion of patients who stop bleeding within 10 minutes from 55% (saline) to 82%. Another randomized controlled trial showed tranexamic acid may be better than vasoconstrictors (ie. phenylephrine-lidocaine) with 90% stopping bleeding at 10 minutes versus 14% (vasoconstrictors). However, efficacy of combining agents is unclear.  Epistaxis is listed in NZF as an indication for oral administration of tranexamic acid while control of oral mucosal bleeding using the IV solution as a mouthwash is listed as an unapproved indication.   The price listed in the NZ Pharmaceutical schedule for the 100m/mL 5mL amps is $5.39 for five amps.   

6.  Resources

(i)  The Antibiotic Conservation Aotearoa website has been set up by a  dedicated group of researchers passionate about promoting responsible antibiotic use and antibiotic stewardship that benefits our whānau.  It includes a resource hub with videos, webinars and infographics which can be used for both prescriber and patient education.  An infographic example can be found here.  

(ii)  An excellent resource for helping you decide whether your patient is fit to undertake a recreational dive medicine course can be found in the on-line document Diving Medical Guidance to the Physician produced by the Diving Medical Screen Committee as part of a new medical screening system for divers set up in 2020. The  guidance looks at various commonly encountered conditions by system and grades them as severe risk, relative risk and temporary risk (and why)  which enables you to have an informed discussion with the patient regarding your recommendations.  

7.  Drug updates

(i) Pharmac has announced the FreeStyle Libre 2 Plus continuous glucose monitor is to be funded from 1 May 2025 for patients with type 1 or type 3c diabetes (due to damage or dysfunction of the pancreas, either from disease or surgery). The new monitor is an upgraded model of the currently funded FreeStyle Libre 2, which will be discontinued in 2026. It can be worn for an additional day (15 instead of 14), and is considered more accurate than the FreeStyle Libre 2. Patients will need a new prescription for this CGM; up to 28 FreeStyle Libre 2 Plus CGMs will be funded each year, or six per prescription.

(ii)  Pharmac has announced that from 1st May, 2025, insulin degludec and insulin aspart (Ryzodeg) will be funded without restriction for patients with type 1 and type 2 diabetes. Ryzodeg is an insulin co-formulation which combines the ultralong-acting insulin degludec (70%) with the rapid-acting insulin aspart (30%). It can reduce the number of insulin injections required for some patients and may improve blood glucose stability. Ryzodeg may also be an appropriate alternative for patients prescribed NovoMix 30 FlexPen, which is being discontinued (supplies expected to run out by mid-2026).

See the latest  Best Practice Bulletin for further details.

8.  Ig Nobel award contenders? 

(i) A recent Medscape update reported findings of an observational study (125 patients undergoing screening colonoscopy given a questionnaire – 43% had hemorrhoids visualized on colonoscopy) that links smartphone use on the toilet with presence of haemorrhoids.  The takeaway points included: 

  • Overall, 66% of respondents used smartphones while on the toilet; 93% of those used a smartphone on the toilet at least one to two times per week or more, and more than half (55.4%) used it most of the time.
  • Smartphone use on the toilet was associated with a 46% increased risk for hemorrhoids after adjustment for age, sex, body mass index, exercise activity, and fiber intake.
  • Participants who used smartphones on the toilet spent significantly more time there than those who did not; 37.3% of them spent more than 6 minutes per visit on the toilet compared with 7.1% of nonusers, and 35% said they believed they spent more time on the toilet because of their smartphone use.
  • The most common activity performed while on the toilet was reading “news” (54.3%), followed by “social media” (44.4%), and email/texting (30.5%)

(ii) Another recent study reported in Medscape looked at that vexed question Can Sharing a Kiss Lead to Gluten Transfer?  It was a small study (10 couples) with the non-coeliac member receiving a gluten load and providing a saliva sample at fixed periods following ingestion, and following a glass of water.   There were two protocols to test gluten transfer via kissing: Waiting 5 minutes after gluten ingestion and then kissing and drinking 125 mL of water after gluten ingestion and then kissing without waiting. The couples were instructed to kiss with an open mouth for at least 1 minute, involving the tongue and saliva transfer. saliva was collected from the partner with celiac disease immediately after the kiss and urine was tested for gluten absorption each evening and the morning after each kissing exposure. Gluten was detectable in the saliva of the partner without celiac disease in all protocols, though not at worrisome levels, according to the authors.  The concluding practice point:  Patients with celiac disease can be more relaxed, knowing that the risk of gluten cross-contact through kissing a partner who has consumed gluten can be brought down to safe levels if food is followed by a small glass of water. 

The New Zealand General Practice Podcast

opotikigp family medicine, general practice, Healthcare , , , ,

Clinical Snippets July 2024

Shownotes

Clinical Snippets July 2024

1.  Heart Foundation resources

New home blood pressure resources – The Heart Foundation has created some handy guidance for patients using a blood pressure monitor at home. There’s a step-by-step guide and a video on how to take accurate blood pressure readings at home, along with a logbook for recording readings.  There are a number pf phone apps available for logging home blood pressure data eg. Blood Pressure Diary. 

2.  Atrial fibrillation and anticoagulation

I have recently reviewed a case where a patient with AF and a mechanical heart valve was swapped from warfarin to rivaroxaban and suffered a stroke several weeks later.  BPAC have published an updated article on atrial fibrillation management.  With respect to anticoagulation in AF:

  • The need for anticoagulant treatment to reduce this risk should therefore be considered immediately following diagnosis.  In primary care, this decision can be guided by balancing the patient’s CHA2DS2-VASc score (stroke risk) against their HAS-BLED score (bleeding risk), although there are no specific cut-offs in the HAS-BLED score to identify patients who should not be initiated on an anticoagulant, particularly as the consequences of a stroke are typically more severe than the consequences of a bleed ie.  an elevated bleeding risk alone does not automatically make patients ineligible for oral anticoagulant use.
  • ACC/AHA 2023 AF guidelines outline that stroke scoring tools such as ATRIA and GARFIELD-AF potentially improve the accuracy of stroke risk assessment compared with CHA2DS2-VASc scoring, and the GARFIELD-AF scoring includes mortality and bleeding risk assessment. However, the guidelines also note that the calibration and performance of ATRIA and GARFIELD-AF has not been as robustly evaluated as CHA2DS2-VASc.
  • Direct oral anticoagulants (DOACs) are typically preferred over warfarin as they are superior for reducing the risk of stroke and all-cause mortality, reduce the risk of intracranial bleeding and have a comparable risk of major bleeding. However, there are some situations in which DOACs are contraindicated (e.g. mechanical heart valves) or there is insufficient evidence to support their use (e.g. moderate-to-severe mitral stenosis, severe liver or renal dysfunction), and warfarin should be used instead.
  • Oral anticoagulants are superior to aspirin and/or clopidogrel for the prevention of stroke, systemic embolism and myocardial infarction in patients with AF, and are associated with a lower risk of major bleeding and intracranial haemorrhage. Long-term antiplatelet medicine use alone is therefore no longer recommended in patients with AF, even if they are at very low risk of stroke (i.e. CHA2DS2-VASc score of 1 for females or 0 for males).  NB Post acute MI situation – confirm intended duration of antiplatelet therapy if unclear.
  • The decision to stop anticoagulant medicines should be based on a continued evaluation of the patient’s stroke and bleeding risk (e.g. determined by CHA2DS2-VASc and HAS-BLED scores) and not because AF has reverted to sinus rhythm or symptom resolution. 
  • With respect to diagnosis of AF, the positive predictive values for AF reported in studies involving wearable devices using photoplethysmography and AF algorithms range from 84 – 98%,suggesting that these alerts are of clinical significance. However, this does not replace the need for usual diagnostic investigations for AF, i.e. pulse palpation and ECG

3.  Pharmac supply updates

(i)  Liquid morphine:  The latest Pharmac update re liquid morphine supplies –  Pharmac listed Oramorph CDC (2mg/mL) from 9 May 2024. It is not Medsafe approved so must be prescribed and dispensed as a section 29 medicine.

Important differences from the RA-Morph brand:

  • Labelled 10 mg per 5 ml (equivalent to 2 mg per ml)
  • Different morphine salt (sulphate instead of hydrochloride)
  • Contains alcohol (ethanol) 10%v/v as a preservative. The alcohol content in 5 ml of Oramorph is equivalent to 10 ml beer or 4 ml wine.
  • Colourless to pale yellow

It appears RA-Morph 1 mg per ml is now back in stock. The supplier has shipped stock to wholesalers in the week beginning 3 June 2024 but there may be some delay in pharmacies replenishing stock.

(ii)  Liraglutide and dulaglutide:  A reminder that from 1 May 2024, Pharmac is limiting funded access to dulaglutide and liraglutide to people already taking these diabetes medicines.  The suppliers of dulaglutide (Eli Lilly) and liraglutide (Novo Nordisk) in New Zealand have advised Pharmac that stock of both medicines for 2024 and 2025 is only enough to meet current demand.

Prescribers should consider clinically appropriate alternative medications, including SGLT2 inhibitors.

(iii)  Oestrogen patches:  Supply of all oestradiol patches remains very limited with Pharmac stating this situation will continue through 2024 and likely for some time into 2025.  The current supply status of each brand and strength of patches is available on the Pharmac website.  As at 13 June 2024 the 25 mcg patches are out of stock in all brands.  Stock of the 50, 75 and 100 mcg strengths is arriving but may not be available at your pharmacy.  

  • Update on 3 July 2024, a new funded brand (Lyllana) is becoming available.  25 mcg patches will be available from late July and 50 mcg Lyllana patches to be available in late August/early September. Monthly deliveries of all strengths of Lyllana patches until the end of the year to start in late September.
  • These patches are not Medsafe approved so will need to be prescribed and dispensed in line with section 29 of the Medicines Act. Pharmac has encouraged the supplier to apply for Medsafe approval.
  • Dr Samantha Newman of the FemaleGP Clinic has produced a very helpful resource for patients and GPs with respect to management options in light of the patch shortage.  This is available from the FemaleGP website (bottom of Home page under  ‘Files for Healthcare Professionals’ – When there are no patches (v2).)

4.  Prescriber Update

The June 2024 Prescriber Update is now available on the Medsafe website.  Brief highlights include:

(i)  Potassium in dietary supplements may lead to hyperkalaemia.  In patients with hyperkalaemia or signs and symptoms suggestive of hyperkalaemia, remember to ask about dietary supplement use. Hyperkalaemia-inducing medicines include angiotensin converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), non-steroidal anti-inflammatory drugs (NSAIDs), spironolactone, potassium supplements, beta blockers, digoxin and trimethoprim.  Some herbal ingredients in supplements contain potassium, including (but not limited to) stinging nettle, evening primrose, turmeric, dandelion. Other supplements may contain potassium as an ingredient or excipient, for example, glucosamine sulfate–potassium chloride complex.

(ii)  Medicine-induced hyponatraemia: increased risks in older people.  Hyponatraemia signs and symptoms range from mild and nonspecific (such as weakness or nausea) to severe and life-threatening (such as seizures or coma).   Hyponatraemia may also be asymptomatic.  In older people, hyponatraemia can be associated with cognitive impairment, gait disturbances and falls and fractures.  The most frequently reported suspect medicines for people >65 years were bendroflumethazide, omeprazole, citalopram, fluoxetine and cholecalciferol but the list of potential culprits is long!   

(iii)  With pseudoephedrine now available again there is a reminder that the drug must not be used in people with uncontrolled hypertension or severe coronary artery disease, concomitantly with monoamine oxidase inhibitors (MAOIs), or in people with hypersensitivity to pseudoephedrine.  Do not use in children aged under 12 years.  Use pseudoephedrine with caution in patients with hepatic or renal impairment, severe hepatic or renal dysfunction, controlled hypertension, hyperthyroidism, diabetes mellitus, coronary or ischaemic heart disease, glaucoma and enlarged prostate.  Additionally, pseudoephedrine is included on the World Anti-Doping Agency (WADA) in-competition prohibited list.  Athletes must stop taking pseudoephedrine at least 24 hours before competition.

5.  Prescribing to competitive athletes subject to drug testing

A recent NZ Doctor article reported the case of a competitive archer banned from the sport for two years after failing a drug test.  The archer tested positive for metoprolol after winning an event at the North Island Senior Target Archery Championships in April. The competitor stated he had been using the substance on the advice of his doctor. All beta-blockers are banned in and out of competition for the sports of archery, shooting and underwater sports.  In addition, they are banned in-competition for some automobile sports, billiards, darts, golf and mini-golf, some ski and snowboarding events   

An earlier NZ Doctor article on prescribing for competitive athletes subject to drug testing included the following points:

  • Athletes must take utmost care in ensuring they do not take any prohibited substances – they cannot rely on doctors and trainers.
  • Before prescribing to a competitive athlete, check whether they are subject to doping testing.
  • Advise athletes to check any medications you prescribe with their medical team.
  • Use an online tool (eg, globaldro.com) to check whether medications and ingredients of supplements are prohibited or permitted.

Drugs may be prohibited out of competition or just in-competition, and some prohibitions are sport specific.  In some circumstances, use of a prohibited drug may be allowed but the athlete must apply for a therapeutic use exemption (TUE).  Some athletes must apply for a TUE in advance (i.e. before using any banned medications or methods). Others can only apply retroactively (i.e. after a positive test).  TUE information and application forms are available on the Drug Free Sport website.   The advice provided to athletes is:

  • Tell your doctor that you’re an athlete and subject to anti-doping rules;
  • If prescribed a medication containing a banned ingredient, ask for a permitted alternative;
  • Know your TUE status (in-advance or retroactive);
  • Keep detailed medical notes for any diagnoses or treatments that involve a banned substance or method;
  • In an emergency, always get the treatment you need.

6.  Montelukast

A recent news article in the BMJ notes the asthma drug montelukast (Singulair) will carry more prominent warnings in the UK to alert doctors and patients to its potentially serious behavioural and neuropsychiatric side effects.  Previously noted side effects associated with the oral treatment include sleep disturbances, depression, and agitation (which may affect up to one in 100 people); disturbances of attention or memory (up to one in 1000); and hallucinations and suicidal ideation (up to one in 10,000).  A similar warning was provided to NZ prescriber in a 2017 Prescriber Update which included the recommendations that prescribers should advise patients that neuropsychiatric reactions can occur with montelukast and patients and/or family members should be instructed to contact a healthcare professional should any neuropsychiatric reaction occur.

7.  Vitamin D supplementation in pregnancy and infants

With winter upon us it’s time to consider local recommendations for Vitamin D supplementation in pregnancy and infants.  The Te Whatu Ora publication covers additional aspects such as appropriate risk benefit discussion, when you might test Vitamin D levels and sun safety advice but the basics include:

  • Risk factors during pregnancy:  naturally dark skin tone; live south of Nelson Marlborough during winter or spring; spend limited time outdoors and/or have minimal sun exposure due to religious, cultural, personal or medical reasons.
  • Offer vitamin D supplementation during pregnancy for women with any of the risk factors.  Prescribe 400 to 800 IU colecalciferol oral liquid per day (Clinicians Vitamin D brand 10mcg/drop is subsidised – dose 1-2 drops per day).  Individuals with all three risk factors in pregnancy may be at higher risk of vitamin D deficiency and blood testing may be considered. Where vitamin D insufficiency or deficiency is confirmed through testing, follow the advice from NZF regarding supplementation doses.
  • Advise people at lower risk of vitamin D deficiency during pregnancy that they may benefit (and are unlikely to suffer harm) from vitamin D supplementation of between 400 IU per day (10 micrograms/day) and 800 IU per day (20 micrograms/day) throughout their pregnancy, particularly in the third trimester.
  • Risk factors for infants less than 6 months:  exclusively breastfed or partially breastfed receiving less than 500 mL of infant formula per day; breastfed over winter/spring months;  a sibling diagnosed with rickets or hypocalcaemic seizures; maternal vitamin D deficiency or higher risk of maternal deficiency; preterm infants and infants who weigh less than 2.5 kg at birth;  naturally dark skin.
  • Offer to prescribe vitamin D supplements to all exclusively or partially breastfed infants as soon as practical, but by 4 weeks until 12 months of age.  Prescribe colecalciferol oral liquid (7,500 IU/mL vitamin D drops, one drop per day.  The subsidised formulation is Puria Vitamin D. Infant formula is fortified with vitamin D so fully formula fed infants or those receiving formula supplementation of >500mL per day should receive adequate vitamin D and do not require supplementation.

8.  Abortion reversal

The RNZCGP has recently released a statement on abortion reversal noting claims that medical abortion can be ‘reversed’ by a dose of progesterone after a woman has taken the first medical abortion medication are not based on reputable scientific evidence. The College upholds views by other medical Colleges’ that the promotion of the term ‘abortion reversal is ‘unproven and unethical’ based on the strength of evidence.   Abortion reversal involves administration of high dose progesterone (vaginally, orally or by injection) after the woman has taken mifepristone but prior to administration of misoprostol if she changes her mind about proceeding with medical abortion.   A 2024 systematic review concluded that based mostly on poor-quality data, it appears the ongoing pregnancy rate in individuals treated with progesterone after mifepristone is not significantly higher compared to that of individuals receiving mifepristone alone.  Despite this, a significant number of states in the USA have enacted medical abortion reversal laws that require patients receive information during pre-abortion counselling, require physicians or physicians’ agents to inform patients, instruct patients to contact a health care provider or visit “abortion pill reversal” resources for more information, and require reversal information be posted on state-managed Web sites.