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The New Zealand General Practice Podcast

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

June 2024

CLINICAL SNIPPETS JUNE 2024

1.  Child Disability Allowance

  • MSD wishes to remind primary care providers of the Child Disability Allowance (CDA).  CDA is paid in recognition of the extra care and attention a caregiver needs to provide for a child or young person with a serious ongoing health condition or disability. The eligibility criteria include the applicant being the main carer of the child and a NZ citizen or permanent resident with both carer and child living and intending to stay in NZ.  The child must be under 18 years and assessed by you as needing constant care and attention for 12 months or more because of a serious disability.
  • The child or young person must need constant care and attention, over and above the ordinary care and attention required by a child or young person of the same age.  This might include frequent attention from another person in connection with their bodily functions or daily living activities, substantially more attention and supervision than is normally required by a child of the same age and gender, or regular supervision from another person to avoid substantial danger to themselves or others.  Examples of situations where the CDA might or might not be considered, and review times, are available on the MSD website. 
  • The CDA is currently $59.23 per week.  It is not taxable or means tested and is provided in recognition of the extra care and attention the child requires.   It isn’t paid to cover costs associated with the child or young person’s disability as these costs aren’t in themselves a qualification for the Child Disability Allowance. However, if the child’s condition does result in significant costs, they may be eligible (in addition) for the Disability Allowance which is means tested. 

2.  Isotretinoin and suicide risk

  • A paper reviewed in issue 56 of Dermatology Research Review looked at risk of suicide and psychiatric disorders among isotretinoin users via a meta-analysis of studies involving  over one and a half million patients.  The findings included the 1-year absolute risk of completed suicide, suicide attempt, suicide ideation, and self-harm among isotretinoin users was less than 0.5% each, while that of depression was 3.83%. Isotretinoin was not associated with the relative risk of all psychiatric disorders, and isotretinoin users were less likely than nonusers to attempt suicide at 2 to 4 years following treatment.  These findings indicate that there is no epidemiological evidence to suggest an increased relative risk of suicide or psychiatric conditions among isotretinoin users at a population level.
  • The authors note that relationship among acne, isotretinoin, and psychiatric disorders is a complex one. Some studies have provided strong evidence for a direct causal relationship between isotretinoin use and mood changes in rare individuals, via biological effects on the central nervous system. This may be an idiosyncratic reaction that is difficult to predict. However, there may be a second indirect effect of isotretinoin on improved mood, mediated by improved acne and self-image which is consistent with the meta-analysis findings.  Hence, while clinicians should remain vigilant and continue to practice holistic psychodermatologic care and monitor patients for signs of mental distress during isotretinoin treatment, they should be aware that isotretinoin appears to be safe at a population level.

3.  Scabies

  • Another paper reviewed in Dermatology Research Review compared the efficacy of topical permethrin (the only topical scabies treatment available in NZ) with benzyl benzoate (BB) for treatment of scabies.  They found a dermoscopy-verified cure rate of 27% in the permethrin group and 87% in the BB group, although the permethrin was far better tolerated than the BB (43% experienced burning sensation).
  • The reviewer (dermatologist Dr L Reiche) noted there are concerns regarding resistance to permethrin.  The current regimen is to apply permethrin from head to toe and wash off after 8–12 hours and then repeat after 1 week.  She suggests with more severe infections permethrin can be applied either daily for 1 week or for 3 days in a row followed by a repeat course after 1 week. It is important to treat contacts. Make sure the hands, face, scalp and under the nails are treated.
  • Health Pathways has a section on scabies treatment that includes considering oral ivermectin (requires Special Authority) for certain situations where oral treatment will be easier to implement, or if topical treatment fails and to repeat the dose after 7 days.  For more comprehensive discussion and advice, there is an excellent 2022 BPAC article available.
  • NZF notes that ivermectin is not approved for more than 2 doses in a course of treatment for scabies and to round the dose to the nearest 3 mg for adults. There is a rare risk of serious or fatal encephalopathy if the patient is co-infected with Loa-loa (African eye worm – endemic to Central and West Africa, where it is transmitted by deerflies). 

4.  ED in a young gym-goer

  • A recent NZ Doctor article presented the case of a younger male requesting sildenafil for ED.  It transpired this apparently fit gym goer was using self-obtained anabolic-androgenic steroids for muscle bulking and had developed secondary hypogonadism.  The author notes that anabolic-androgenic steroids (AASs) are one of the major concerns in professional and amateur athletes, particularly young men in their 20s and 30s who practise weightlifting to increase their muscle mass and improve their physical appearance. The prevalence of AAS use/abuse in this population is estimated to be approximately 5 per cent among all gym-goers (in a single study in Germany, it reached 13.5 per cent of gym clients) and 25–50 per cent among competitive bodybuilders.
  • The article discusses the multi-disciplinary approach (GP/endocrine/SH/psychologist) required if the patient wants to stop use of AASs and that on-demand sildenafil or daily tadalafil can be used temporarily to improve erectile function, as a component of the MDT plan. Isolated on-demand prescription of sildenafil for anabolic steroid induced hypogonadism (as requested by the patient) is futile as it is doomed to failure and can only serve the unhelpful purpose of delaying the comprehensive management of the syndrome.  However, one survey of AAS users found that 58.1 per cent of respondents felt it was unlikely or very unlikely they would stop AAS use in the next five years.  Message:  Ask about AAH use in younger patients presenting with ED. 

5.  PRESCRIBING UPDATES

(i)  Pharmac is funding the first single inhaler triple-therapy from 1 May 2024. Fluticasone furoate with umeclidinium and vilanterol (branded as Trelegy Ellipta) will benefit around 15,000 people with chronic obstructive pulmonary disease (COPD) in the first year of funding. For most people, this will mean switching from using two or three separate inhalers to using just one. NZ Formulary notes the indications as:  maintenance management of asthma in those not adequately controlled with combination inhaled corticosteroid and long-acting beta2-adrenergic agonist; maintenance treatment of moderate to severe chronic obstructive pulmonary disease.

(ii)  May NZF updates refer to a new section on Testosterone and management of menopausal symptoms.  This notes topical low-dose (10 mg/mL) testosterone cream may be considered for post-menopausal females who experience concern with hypoactive sexual desire dysfunction.  [Ssection 29, unapproved medicine – Androfeme $153 – 50mL tube, dose 0.5 – 1 mL daily.  The subsidised male formulations, Testogel, come in a 1% and 1.6% formulation with amounts dispensed per actuation of 12.5mg and 20.25mg respectively].     Careful education and correction of modifiable biopsychosocial factors affecting sexual desire should be trialled prior to testosterone treatment and referral to a specialist should be considered. Measure base-line testosterone level, liver function, full blood count, HbA1c, and lipids prior to treatment. Testosterone level should be measured again after 4–6 weeks to ensure the normal pre-menopausal female range is not exceeded. Reassess all parameters 6 and 12 months after initiation and then at least annually thereafter once treatment is stabilised. Discontinue after 6 months if no improvement in sexual function. Long-term safety data (longer than 24 months) for the use of testosterone in females at physiological doses is lacking, refer to product literature.

(iii)  ACEs – new starting dose for hypertension in individuals who are elderly, on concomitant diuretics, or at risk of ACE inhibitor-induced hypotension: 

  • Quinapril, lisinopril,   5mg daily
  • Captopril 6.25 – 12.5mg
  • Perindopril 2mg
  • Enalapril 2.5mg

(iv)  Quinolones:  new note added to cautions: Quinolones have been associated with prolonged, disabling, and potentially irreversible serious adverse reactions with reference to a September 2023 Prescriber Update .  Potential adverse reactions listed under this heading are:

  • Tendon damage
  • Aortic aneurysm/dissection
  • Heart valve regurgitation
  • Seizures
  • Psychiatric changes
  • Peripheral neuropathy

(v)  Aspen NZ, the supplier of Eltroxin® (levothyroxine) has informed Pharmac that the 50mcg and 100mcg tablets are changing in appearance. The new Eltroxin® (levothyroxine) 50mcg and 100mcg tablets were listed on the Pharmaceutical Schedule from 1 May 2024.  Aspen NZ has provided some materials to prepare you, and people who take Eltroxin, for this change:

(vi)  Medsafe have released a safety alert regarding oral promethazine products with the following information:

  • Promethazine (oral) is now contraindicated in children under 6 years of age (previously under 2 years of age).
  • A safety review identified a high risk of psychiatric and central nervous system side effects in this age group, including psychomotor hyperactivity, aggression and hallucination. Difficulties in learning and understanding, such as reversible cognitive deficit and intellectual disability, may also occur when high doses are given.
  • Use alternative treatment options for children under 6 years of age requiring allergy or nausea treatment. Refer to local guidelines.
  • There will be a time lag before medicines with updated package labelling are available in pharmacies.
  • Remind consumers who may have this medicine at home not to use it in children under 6 years of age and to consult a pharmacist or doctor for alternative treatment options and advice.

6.  He Ako Hiringa and the EPIC Dashboard

  • Pharmac sponsorship of He Ako Hiringa ends on 30 June 2024 but the service will continue under new ownership although with reduced staffing resource which will mean a reduction in publication of new resources.  Prescribing data is currently available as at 31 December 2023. 
  • The EPiC dashboard uses dispensed medicine data to create an interactive, personalised, report-style dashboard. Once logged in, you can explore prescribing trends for your patient population, your practice and nationally for a range of defined themes with RNZCGP approved audit and reflection templates available for completion.  Prescribing themes you can explore currently include antibiotic use, type-2 diabetes, asthma, opioids, gout, CVD and youth mental health. 

7.  The end

The early May issue of NZ Doctor (requires log-in) contains a medicolegal article on knowing your rights in the face of threatening behaviour from patients.   It is presented as a series of scenarios including: 

  • The patient is verbally abusive and rants at staff, causing us to feel unsafe. We want to call the police, but the patient says that if we do, it will be a breach of their privacy. What can we do?   Rule 11 of the Health Information Privacy Code 2020 provides that you can disclose information if it is “necessary to prevent or lessen a serious threat to public health or public safety, or to the life or health of the individual concerned or another individual”. The disclosure must be to someone who can do something about the threat (eg, the police).
  • The patient yelled at the receptionist and upset waiting patients. We don’t feel safe having them on our books, but no other practice has room for new patients. Do we have to keep them as a patient?  No. You can end the relationship or, as a compromise, enter into a behaviour contract to give the patient another chance. As long as the patient does not require urgent care, then the Medical Council of New Zealand guidelines for ending a doctor–patient relationship specifically allow that “if the patient is abusive, violent or poses a significant safety risk to you or your colleagues”, you can end the relationship. This is provided the steps are followed as set out in the MCNZ guidelines.
  • The article also covers issues such as when and how to issue a trespass notice and when you might consider applying for a restraining order.  Of course lower level resolution of issues that might lead to such behaviours is preferred and de-escalation training is available through a number of agencies (eg WorksafeReps) and a 1 hour training webinar is presented on My Health Hub. 

The New Zealand General Practice Podcast

opotikigp family medicine, general practice, Healthcare , ,

Clinical Snippets May 2024

Clinical Snippets May 2024

1.  ACC – Integrated Care Pathways Musculoskeletal (ICPMSK)

(i)  ACC has launched the Integrated Care Pathways Musculoskeletal (ICPMSK) described as an innovative way of supporting people with injuries that require multiple rehabilitation services, designed for kiritaki/clients needing more integrated, specialised and coordinated treatment. Services may include physical rehabilitation, assistance with return to work, specialist opinion and navigation through the ACC and health system via a team of health providers called the ICPMSK interdisciplinary team.

(ii)  Referral into the programme require the following criteria:

  • Accepted cover for a non-permanent musculoskeletal injury to their lower back, shoulder and/ or knee.
  • Intend to reside in Aotearoa New Zealand for the duration of the programme.
  • The injury happened within the last 12 months at time of referral
  • [Exceptions:  If the time between the date of the accident on a claim and the date of the referral to ICPMSK is greater than 12 months, entry to ICPMSK will only be appropriate for kiritaki with these suspected or confirmed diagnoses:
  • ligament rupture with conservative management
  • post-traumatic osteoarthritis (for example, ACL rupture ≥ 15 years ago)
  • dislocation of shoulder
  • previous surgery with internal fixation where removal of metalware is being applied for.
  • The injury carries a high chance of needing surgery.
  • The injury must be of a level of complexity that is likely to require specialist oversight and interdisciplinary treatment to achieve a return to work or return to independence. For example, in the shoulder this might be a full-thickness tear of the rotator cuff, or an AC joint dislocation. In the knee it could be a rupture of the ACL. In the lower back it could be a lumbar disc prolapse that causes pain in the leg.

(iii)  To refer (with patient knowledge and consent):

  • Contact the ICPMSK supplier in your region. A list of suppliers can be found on the ACC website.  Ease of referral varies but e-referrals are possible with many.  Request ICPMSK pre-screen and provide the relevant claim number. 
  • A member of the supplier’s ICPMSK team contacts the kiritaki to discuss the injury and their recovery so far. This pre-screen will help establish if they’re likely to meet the service entry criteria.  Kiritaki that pass the pre-screen will go through further assessment (such as a physical exam, x-ray/CT, and/or medical specialist review) to determine suitability for the programme. 

2.  Amoxicillin dosing in acute otitis media

(i)  A recent article in the European Journal of Pediatrics reviewed in Issue 27 of NZ Child Health Research Review  compared the  efficacy and tolerance of amoxicillin administered twice and three times daily in children with acute otitis media.  The clinical course of acute otitis media was favourable in 92% of children who received amoxicillin twice daily and in 95% of those who received amoxicillin three times daily (not significant).

(ii)  Overall, 31% of those who were prescribed amoxicillin three times daily reported difficulties with the dosing schedule, and 9.6% found it difficult to take the specified volume of medication, compared with 5.8% and 25% of those who were prescribed the twice-daily regimen, respectively.

(iii)  The reviewer’s comment: I’m sure this finding applies to many drugs used in childhood where the evidence for three times daily administration is based on scant evidence. Linking dosages to when the child brushes their teeth morning and night may not only assist with successful treatment with oral medications but may possibly also benefit oral hygiene!

3.  Microplastics, nanoplastics and CVD risk

(i)  A study published in the NEJM in March reported on a prospective, multicenter, observational study involving patients who were undergoing carotid endarterectomy for asymptomatic carotid artery disease. The excised carotid plaque specimens were analyzed for the presence of MNPs.  The primary end point was a composite of myocardial infarction, stroke, or death from any cause among patients who had evidence of MNPs in plaque as compared with patients with plaque that showed no evidence of MNPs over approximately three years of follow-up. 

(ii)  58% of patients had polyethylene had MNPs detected in carotid plaque and 12% also had polyvinyl chloride MNPs detected.  Electron microscopy revealed visible, jagged-edged foreign particles among plaque macrophages and scattered in the external debris. Patients in whom MNPs were detected within the atheroma were at higher risk for a primary end-point event than those in whom these substances were not detected with a hazard ratio of 4.53. 

Stop drinking bottled water!

4.  COC + NSAID

(i)  A large Danish study reviewed in Issue 219 of Respiratory Research Review evaluated the risk of VTE while receiving hormonal contraception and NSAIDs in 2 million women aged 15–49 years, living in Denmark from 1996 to 2017. All women were free of known arterial or venous thrombotic conditions and did not have cancer or thrombophilia, and investigators excluded periods during which the women might have been put at higher VTE risk from other causes, including pregnancy and related events, surgeries requiring hospitalization, and the use of other drugs that carry a risk of thrombosis. Over 21 million person-years of follow-up, 8710 VTE events occurred. 

(ii)  With the use of NSAIDs, the risk of VTE was seven times higher than in non-users, among women who were not on hormonal contraception (HC).  Compared with non-NSAID users, the risk of VTE in women taking an NSAID was 11 times higher in women on high-risk HC[1], eight times higher in those on medium-risk HC and 4.5 time higher in those on low/no risk HC.   The corresponding numbers of extra venous thromboembolic events per 100 000 women over the first week of NSAID treatment compared with non-use of NSAIDs were 4 (3 to 5) in women not using hormonal contraception, 23 (19 to 27) in women using high risk hormonal contraception, 11 (7 to 15) in those using medium risk hormonal contraception, and 3 (0 to 5) in users of low/no risk hormonal contraception.

(iii)  The authors concluded: NSAID use was positively associated with the development of VTE in women of reproductive age. The number of extra VTEs with NSAID use compared with non-use was significantly larger with concomitant use of high/medium risk hormonal contraception compared with concomitant use of low/no risk hormonal contraception. Women needing both hormonal contraception and regular use of NSAIDs should be advised accordingly.  The authors point out that the absolute risk of VTE remains low despite the increase in risk over the first week of NSAID use.

5.  MANA

(i)  Issue 95 of the Best Practice Bulletin refers to the New Zealand Dementia Foundation release of Māori Assessment of Neuropsychological Abilities (MANA), a suite of diagnostic tools for evaluating mate wareware (dementia) in Māori.  MANA is intended to facilitate comprehensive assessment that is sensitive to Māori cultural needs, and is thought to be the first dementia assessment in the world incorporating a wairua (spiritual) evaluation. It is encouraged that these resources are considered when assessing dementia in Māori, and they may be particularly useful for clinicians wanting to increase their cultural competency skills and knowledge.

(ii)  The MANA tool has four key components:

  • A history-taking tool that guides you through taking a comprehensive history when seeing a person and their whānau for an assessment of possible dementia mate wareware.
  • A wairua and well-being tool. This component covers areas such as wairua (spirit), role, and identity that were identified as important in the preparatory research.
  • A cognitive tool, that is scored, with lower scores suggestive of dementia mate wareware.
  • A whānau or family tool that assesses symptoms and signs from a whānau, friend, or care-giver perspective. This component is also scored.

(iii)  The MANA suite may take up to an hour to work through, in much the same way as the whole of the general Cognitive Impairment Community Health Pathway may take an hour to work through. Similarly, splitting the MANA process into sections and involving more than one clinician may be essential, especially in the primary care setting.

(iv)  The website includes training videos, tips on the hui process and a manual in addition to links to each of the tools.  For general information on diagnosing dementia, including special considerations for Māori, see: “Recognising and managing early dementia” bpacnz, 2020.

6.  Apathy in dementia

(i)  A recent Tools for Practice from the Canadian College of Family looked at evidence for efficacy of medications for apathy in dementia.  Specifically, in patients with dementia, how safe and effective are stimulants, antidepressants, and antipsychotics for treating apathy?  The bottom line was that methylphenidate (10mg BD immediate release) may improve apathy scores by a small but potentially clinically meaningful amount compared to placebo (example: 5 points more on a 72-point scale) at ~12 weeks. Methylphenidate does not impact cognition in randomized, controlled trials (RCTs). Antipsychotics and antidepressants do not improve apathy compared to placebo

(ii)  Additional referenced context is provided:

  • No improvement in apathy with cholinesterase inhibitors alone versus placebo, but 60-100% of RCT methylphenidate patients used cholinesterase inhibitors.
  • Methylphenidate associated with weight loss, behavioural changes, insomnia, and cardiovascular harms.
  • Depression and apathy often overlap and can be difficult to distinguish in practice.
  • Non-pharmacologic options include sensory stimulation (example music therapy) and pet therapy based on low-quality evidence of benefit.

7.  RSV vaccine for adults

(i)  GSK has registered their adult RSV vaccine Arexvy in New Zealand from 1 May 2024. A funding application for Arexvy has also been submitted to Pharmac for their assessment.  The Medsafe data sheet notes Arexvy is indicated for active immunisation for the prevention of lower respiratory tract disease (LRTD) caused by respiratory syncytial virus RSV-A and RSV-B subtypes in adults 60 years of age and older.  

(ii)  Further information regarding the vaccine is available on the IMAC website.  This notes Arexvy is a recombinant protein vaccine that causes the immune system to produce RSV antibodies. It includes an adjuvant that enhances the immune response to the vaccination.    A single dose of Arexvy is highly effective at preventing serious respiratory illness from RSV for at least two seasons (around 80% effective overall, 94% effective against severe RSV illness), including in those aged over 70 and those with at least one underlying health condition.  Getting a second dose a year later offered little additional benefit compared to just one dose for two seasons and research is ongoing regarding optimal revaccination timing.

(iii)  Those adults aged 60 years and older who are at higher risk of severe RSV disease include:

  • people with chronic medical conditions including: respiratory, cardiovascular, neurological, haematological conditions, diabetes, or liver or kidney disorders
  • people with moderate or severe immune compromise
  • people who are frail
  • people aged over 80 years*
  • people living in nursing homes or other long-term care facilities
  • older people of Maori and Pacific ethnicity, especially if living in areas of high deprivation

*The risk of severe RSV among adults increases with age, with the highest rates of hospitalisation among those aged 75 years and older. Although age may be considered in determining an older adult patient’s risk for severe RSV-associated disease, there is no specific age threshold at which RSV vaccination is universally recommended within the age group of adults ages 60 years and older.

(iv) The vaccine press release (picked up by several newspapers at the start of the month) concluded: The Arexvy vaccine will be available for private purchase from GP clinics from 1 May 2024. The most common side effects are injection site pain, fatigue, muscle pain, headache, and joint pain.  The vaccine is currently unsubsidised. I have been unable to confirm a NZ price for the vaccine but in the US the list price is $US280 ($NZ470)

(v)  An unrelated aside:  Astra Zeneca announced yesterday that it is withdrawing its Covid vaccine, Vaxzevria, from the European market and likely globally citing reduced demand with sales not generating a profit since mid-2023.  IMAC notes Vaxzevria has not been available in NZ since September 2022 when exiting supplies expired.      Novavax’s Nuvaxovid remains as the non-mRNA option for those not wanting or not being able to have a Pfizer COVID-19 vaccine.  However, Pharmac have advised changes to the availability of Nuvaxovid from 1 May 2024. The current supply of this vaccine has expired.  The latest Novavax XBB vaccine application is currently being considered by Medsafe and the assessment is in its final stages.  This means there will be no Novavax XBB vaccine available from 1 May until the new vaccine is approved. Supply of the Pfizer XBB.1.5 COVID-19 vaccine (branded as Comirnaty) is unaffected, and continues to be available in New Zealand.

8.  Cycling to work

(i)  Issue 232 of GP Research Review reported on a paper ‘ Does cycle commuting reduce the risk of mental ill-health?’.   The paper reported on data from almost 400,00 individuals in Scotland, detailing their mode of transport to work according to the 2011 population census, and their prescriptions for mental health as per national records.  In Glasgow and Edinburgh, 1.85% and 4.8% of commuters cycled to work, respectively. A lower proportion of cyclists received a prescription for mental health than non-cyclists (9% vs. 14%), and cyclists were estimated to receive 15% fewer prescriptions for antidepressants or anxiolytics over the following 5 years.

(ii)  The reviewer noted there are many potential variables that are not addressed or acknowledged in the research such as is there a specific advantage in cycling as exercise, social or socioeconomic differences between the two groups and age loading.   In the meantime cycle commuting may be beneficial for your mental health provided you wear a helmet and don’t fall off!  

[1] High-risk HC includes tablets containing 50 µg ethinyl oestradiol, or the progestins desogestrel, gestodene, drospirenone, or the anti-androgen cyproterone. Medium-risk HC comprises all other combined oral contraceptives and depot medroxyprogesterone injections. No- or low-risk HC includes progestin-only oral contraceptives and implants and the LNG-IUDs.

The New Zealand General Practice Podcast

opotikigp family medicine, general practice, Healthcare , , , , , , ,
Clinical Snippets February 2024

Shownotes

Clinical Snippets February 2024

1.  ACE and ARB and statin use in pregnancy – DON’T

The NZF notes that ACE inhibitors should be avoided at all stages of pregnancy. Fetal skull defects have been reported following first trimester exposure to ACE inhibitors although evidence of teratogenicity is inconclusive. In the second and third trimesters ACE inhibitors can cause abnormalities including fetal growth retardation, oligohydramnios and fetal or neonatal renal failure. Fetal death in utero has also been reported. Pregnant women who are taking an ACE inhibitor should be changed to an alternative antihypertensive as soon as possible.  Like ACE inhibitors ARBs should be avoided in pregnancy, particularly in the second and third trimesters, as similar effects to those caused by ACE inhibitors in pregnancy are expected.  

NZF notes also that Statins should be avoided in pregnancy as congenital anomalies have been reported and the decreased synthesis of cholesterol possibly affects fetal development. The individualstatin monographs state the drug is contraindicated during the first trimester and adequate contraception is required during treatment and for 1 month afterwards.  However, a 2022 metanalysis and systematic review noted there are some patients for whom there may be a significant benefit of maintaining statin therapy, in particular in the second and third trimesters. The risk and benefit of statins treatment during pregnancy need to be evaluated in an individualized approach and every trimester apart.

2.  Monitoring lithium drug interactions

A September NZ Doctor article on monitoring drug interactions with lithium is a helpful refresher on monitoring recommendations for patients on lithium therapy:

(i)  Usual monitoring: (current reference range for chronic use is 0.6-0.8 mmoL/L):

  • Three to six-monthly (depending on stability) – serum lithium level, electrolytes, eGFR.
  • Six-monthly – thyroid function, calcium, weight.
  • Annually (if over age 40 or obese) – HbA1c, lipids, consider ECG.

(ii)  When adding or removing medicines:

  • ACE inhibitors – baseline serum lithium level and renal function tests, then weekly for six weeks or until stable. For “at-risk” people (impaired renal function, volume depletion or heart failure) consider further two-weekly checks for six weeks.

20 to 35 % of people will have an increase in lithium levels if an ACE inhibitor is added to their regime, usually by around 33 %. The interaction can be delayed for up to five weeks, so it is important not to be reassured by steady lithium levels initially.  ARB interaction less likely but dose dependent (ARB) increases in lithium levels of up to 20 % after up to five weeks of treatment have been reported. 

  • Diuretics – baseline serum lithium level and renal function tests, then weekly for four weeks.

If a thiazide needs to be introduced, there may be a rapid increase in serum lithium levels by 20-25 % in 3-10 days, although this effect may also be delayed.  Loop diuretics have less impact, with potentially only up to a 20% increase in levels, and potassium-sparing diuretics appear to have no effect.

  • NSAIDs – baseline serum lithium level and renal function tests, then weekly for two weeks or until stable.

This interaction is well described for decreasing lithium clearance and increasing its toxicity, although it is unpredictable. While the average decrease in lithium clearance is usually 10-25%, there is wide variation, especially in people with impaired renal function. It is unlikely that COX-2 inhibitors would be any different to traditional NSAIDs regarding this interaction.

The risk is cumulative with concomitant use of ACE inhibitors, diuretics and NSAIDs.

3.  Shared care clozapine

The October 2023 NZ Doctor includes a refresher on shared care prescribing of clozapine.  Points include:

(i)  Clozapine can only be initiated by a psychiatrist. In some localities within Te Whatu Ora, GPs and nurse practitioners can be responsible for ongoing prescribing under the supervision of a psychiatrist. GPs can also prescribe for those with stable illness in collaboration with a community mental health team.  Patients are considered stable if they have been taking clozapine continuously for two years, had no mental-health-related hospital admissions in the last 12 months, are not taking other medications requiring close monitoring by a psychiatrist, and have been adherent to treatment and attending appointments.

(ii)  Due to the risk of agranulocytosis, all patients prescribed Clopine in New Zealand must be registered to ClopineCentral™ (the Clopine Monitoring System) or CareLink Plus (the Clozaril Monitoring System) by a registered medical practitioner.  Prescribing physicians must also register themselves onto the relevant monitoring system to access patient information. Brand swapping between clozapine products is discouraged and should occur on the advice of the initiating clinician or team. 

(iii)  The adverse effect and drug interaction profile of clozapine is wide (in particular agranulocytosis, severe constipation and cardiomyopathy/myocarditis) and there are specific requirements for pre-prescribing screening and subsequent monitoring which are critical to reduce the risk of patient harm.  There is comprehensive practical information available on HealthPathways (not yet localised for Midlands) and in publications by BPAC (2017) and SafeRx. 

(iv) Clozapine levels are reduced by cigarette smoking; however, it is the constituents of smoke, not nicotine itself, that is responsible.  Elevated clozapine levels, up to double baseline, may occur when patients stop smoking and this is not affected by NRT.  If patients stop smoking it is advisable to monitor plasma clozapine levels, dose reduction may be required in conjunction with mental health service advice. Conversely, if a patient starts smoking during treatment, the therapeutic effect of clozapine may be reduced. The plasma concentration of clozapine can also be increased by a high caffeine intake (more than 400mg/day – colas, tea and many energy drinks contain significant amounts of caffeine). Clozapine levels can subsequently decrease by nearly 50% after a 5-day caffeine-free period.

(v)  The article concludes:  Every time a patient comes in, there is an opportunity to query about adverse effects (with a focus on smoking status and bowel habits), check they are taking their medication appropriately, and offer lifestyle advice. Blood test results should be checked and compared with baseline. It is also important to ensure patients are aware of the need for blood tests to be done on the day they are due.  The Porirua Protocol is an evidence-based bowel management regime for patients taking clozapine.  

4.  PAD – best practice and equity

Issue 106 of the Maori Health Review reported a recent retrospective study from the Midland region on prescribing of cardioprotective medications and the impact on survival for patients with peripheral artery disease that undergo intervention.  Findings included:

  • Overall, 80.7% of patients received a prescription for antihypertensive medication, 77.4% for lipid-lowering medication and 89.9% for antithrombotic medication with prescribing of all three noted as ‘best medical therapy’.
  • Patients with concomitant ischaemic heart disease were more likely to be prescribed cardioprotective medication. Women were less likely to be prescribed lipid-lowering medication than men and younger patients were less likely to be prescribed lipid lowering medication than older patients.  Māori men were less likely to be prescribed antiplatelet medication compared with non-Māori men although were more often prescribed antihypertensive agents and no significant difference in statin prescribing.
  • Lipid-lowering and antiplatelet medication showed a survival advantage on univariate analysis, while antihypertensive and anticoagulant medication did not. Best medical therapy was associated with better survival after adjustment for age, sex, end stage renal failure and presence of chronic limb-threatening ischaemia.

On the equity theme, there is a great article from Cook Street Medical Centre in the January edition of GP Voice about their equity journey and outcomes. 

5.  Medsafe monitoring communication

In January Medsafe released a monitoring communication regarding the DPP4 inhibitor vildagliptin (Galvus, Galvumet).  The communication requested reporting to CARM of any patients on the medication being diagnosed with ileus.  While there is insufficient evidence currently to confirm any association between use of DPP4 inhibitors and ileus, the association may have biological plausibility as DPP-4 inhibitors act by inhibiting the breakdown of endogenous glucagon-like peptide-1 (GLP-1), which has a role in inhibition of gastrointestinal motility.

6.  Resource 1:  Pregnancy-related and post-natal depression and anxiety

Online mental health provider, Just a Thought, has launched CBT courses titled Pregnancy Wellbeing and Postnatal Wellbeing for women who experience depression and anxiety during their perinatal journey. The courses are evidence-based and free of charge.  You can refer your patients and follow their progress via the on-line dashboard once you are registered as a clinician with Just a Thought, or the patient can self-access.

7.  Resource 2:  Skin Cancer Symposiums

Educational provider Skin Cancer Symposiums offers a variety of on-line and in-person courses aimed at facilitating accurate and timely diagnosis of skin cancers, particularly melanoma.  They are currently offering a complimentary on-line mini-course on the basics of dermatoscopy and diagnosing melanomas (Register here)  with the goal of the course described as: to facilitate the basic understanding of the visual “red flags” of diagnosing melanoma.  In all of the cases presented, we include clinical and dermatoscopic images. In some, the diagnosis will be evident in the clinical image and reviewing the dermatoscopic image will further reinforce this. In some examples, the diagnosis is only evident in the dermatoscopic image.

8.  Covid vaccine 2024

Manatu Hauora confirmed at the end of December that a vaccine to combat the newer strains of COVID-19 has been approved by Medsafe and will be available to New Zealanders in time for winter 2024.  The COVID-19 XBB.1.5 (Comirnaty® Omicron XBB.1.5) has been approved for the 12+ age group with no plan reported for any changes in current eligibility criteria.   Eligible people are encouraged not to defer booster shots of the existing vaccine if due in view of prevalence of Covid-19 in the community.  While the most prevalent subvariant currently internationally and in NZ is JN.1, the receipt of updated SARS-CoV-2 vaccines containing the monovalent XBB.1.5 spike protein is anticipated to provide protection against JN.1[1].

[1] https://www.idsociety.org/covid-19-real-time-learning-network/vaccines/will-covid-vaccines-continue-to-work-against-jn.1-and-other-new-variants#/+/0/publishedDate_na_dt/desc/