Published: 23 July, 2021
Contents
COVID-19 vaccination and the risk of myocarditis
The Immunisation Advisory Centre (IMAC) is monitoring clinical aspects of the COVID-19 Pfizer vaccination programme. They have been made aware of an increased number of cases of myocarditis and pericarditis, occurring in particular after the second dose of the Pfizer vaccine and more often in younger people, especially younger males. Primary care clinicians should be aware of the risk, know the likely presenting symptoms of suspected vaccine-related myocarditis and pericarditis and how these people with should be managed (see: Read
more). Reported cases have generally been mild and guidance from the United States Advisory Committee on Immunization Practices (ACIP) is that “the benefits of mRNA COVID-19 vaccines continue to outweigh the risks of myocarditis and pericarditis even among young people”. The WHO Global Advisory Committee on Vaccine Safety will continue to monitor the data and provide updated information on the potential risks and recommendations for COVID-19 vaccination. Medsafe has also released
a safety communication regarding this rare adverse reaction and the data sheet for the vaccine will be updated.
Read more
A
statement from the WHO Global Advisory Committee on Vaccine Safety on 9 July, 2021 noted that clinicians need to be aware of the risks of myocarditis and pericarditis following COVID-19 mRNA vaccination and be aware of those who are most likely to be affected. Myocarditis or pericarditis should be considered in people who have been vaccinated who present with symptoms such as acute chest pain, shortness of breath and palpitations, especially younger males.
Since April, there have been increased reports of myocarditis or pericarditis being diagnosed in the first few days following receipt of the Comirnaty (Pfizer) mRNA vaccine. The cases have tended to follow the second dose of vaccine and have been more often in younger males. Countries most affected have been those with the largest number of vaccine recipients aged under 30 years, e.g. initially in Israel and then in the much larger United States (US) population.
Based on confirmed cases reported to the US Vaccine Adverse Events Reporting System (VAERS), a passive surveillance system equivalent to CARM in New Zealand, the incidence of myocarditis or pericarditis in young men aged 12-29 years was approximately 40 cases per million second doses of a mRNA vaccine (or 1 in 25,000). Cases in young women were around 10-fold lower (4.2 cases per million or 1 in 250,000). The incidence in those aged over 30 years is lower again (about 1 in 400,000 in males and 1 per million in females). N.B. It is not currently known if the risk differs between the Pfizer and Moderna vaccines as data is combined. Among people with reported myocarditis after mRNA vaccination, the median age was 26 years (range = 12 – 94 years), with median symptom onset interval of three days after vaccination (range = 0 – 179 days). Among the cases where the number of mRNA vaccine doses received was reported, 76% occurred after the second dose. In the US, approximately 90% of the 303 confirmed cases of myocarditis following mRNA vaccination were hospitalised; as of 23 June, 95% had been discharged and 81% were fully recovered.
The clinical presentation and severity of myocarditis and pericarditis varies among patients, however, most cases associated with vaccination are generally mild. Symptoms typically include chest pain, dyspnoea after exercise or lying down, or palpitations. When people with such symptoms are seen, it is important to ask if they have received their COVID-19 vaccination in the previous few weeks. Investigations should include requests for troponin and CRP and an electrocardiogram (ECG). Most patients with myocarditis and pericarditis following vaccination will respond to conservative treatment, e.g. rest and analgesia, but referral to cardiology for further management and follow-up may be indicated as admission for monitoring and supportive therapy may be required. Other potential causes of myocarditis, such as viral infections including COVID-19, or rheumatological causes will need to be ruled out. Current guidelines also recommend exercise restriction until the heart recovers.
All suspected cases of myocarditis and pericarditis should be reported to CARM. Medsafe is closely monitoring for any reports of myocarditis following COVID-19 vaccination in New Zealand. This information will be important to inform any possible changes to the vaccination schedule or strategy.
High demand for prednisolone oral liquid (Redipred)
Shipping disruptions and increased demand due to the high number of cases of respiratory conditions such as RSV in children in New Zealand have resulted in short
supply of prednisolone oral liquid (Redipred). PHARMAC has released figures stating that the average demand for prednisolone oral liquid is around 8,500 bottles per month, but during June, 2021, demand rose to over 15,500 bottles. PHARMAC has been able to access new stock rapidly with support from the Ministry of Foreign Affairs and Trade, Customs and the Ports of Auckland. Stock is being replenished urgently to wholesalers and most pharmacies should have had supplies back in stock this week. Demand remains high so plans are in place to ensure ongoing supply.
If prescribers become aware that their local pharmacy does not have stock of prednisolone oral liquid on hand, an alternative option is to prescribe an equivalent dose of prednisone tablets. These can be crushed and mixed with soft food or water immediately prior to administration to the child; clear instructions will need to be given by the pharmacist to parents and caregivers.
The United Kingdom has been experiencing a similar increase in the number of children with respiratory conditions as lockdown restrictions ease, despite being in the middle of summer. Large future outbreaks of RSV and other respiratory conditions post COVID-19 restrictions have been predicted
worldwide due to the increase in the susceptible populations for these types of infections.
Rasagiline funded from 1 August for Parkinson’s disease
Selegiline, a monoamine-oxidase-B inhibitor used in the treatment of Parkinson’s disease, is to be delisted in early 2022 due to the supplier (Apotex) leaving the market. An alternative brand of this medicine was unable to be sourced. Current restrictions to prescribing selegiline are outlined
here.
PHARMAC
has announced that it will fund rasagiline (brand name Azilect) from 1 August, 2021; this is also a monoamine-oxidase-B inhibitor for the treatment of Parkinson's disease. PHARMAC has received clinical advice from the Neurological Subcommittee of PTAC that rasagiline may be a suitable alternative treatment for people currently taking selegiline. Short-term supplies (approximately six months) of two brands of selegiline will be available to help provide more time to transition people taking selegiline to rasagiline or another treatment. One patient co-payment will be paid by PHARMAC for one general practice visit per patient to support patients through this change. No new patients will be able to be initiated on selegiline from 1 August, 2021.
Rasagiline does not have Medsafe approval as yet (application is underway), therefore, it will need to be prescribed and supplied under Section 29 of the Medicines Act (Apo-Selegiline has also been supplied under Section 29 for some time). The Australian medicine data sheet for rasagiline lists the recommended dose as 1 mg, once daily.
Brand change for febuxostat
PHARMAC has advised that the funded brand of febuxostat (Adenuric) is to change. From 1 August, 2021, the funded brand will be Febuxostat Multichem. Adenuric will be delisted on 1 January, 2022. PHARMAC has produced a patient information pamphlet which can be downloaded
and printed here. If febuxostat is prescribed generically, prescribers will not need to change anything as pharmacists will be able to dispense Febuxostat Multichem when new prescriptions are presented from 1 August onwards and explain the change to patients. A brand switch fee will be available for pharmacists. The new brand of febuxostat is no different in appearance to the current funded brand.
Boron-containing medicines and fertility concerns in children
The Medicines Adverse Reactions Committee (MARC) has
recommended that a statement be added to medicine data sheets of boron-containing medicines, such as chloramphenicol eye drops, based on theoretical evidence that use may adversely affect future fertility. This advice specifically relates to use of boron-containing eye drops in children aged under two years.
Chloramphenicol eye drops administered as one drop four times a day for the treatment of bacterial conjunctivitis is unlikely to exceed the threshold for boron in children aged under two years. Chloramphenicol ointment does not contain boron and therefore can be used as an alternative if caregivers are concerned.
Read more
In 2017 the European Medicines Agency (EMA) advised that data sheets and patient information must contain a contraindication and a warning about fertility concerns for children aged under two years where a medicine is used with a dose exceeding the threshold of 1 mg boron/day. The fertility concerns are based on animal studies where boric acid is associated with dose-related effects on developmental and reproductive toxicity, however, the significance of this in humans is unclear.
Medicines that contain boric acid or borates as excipients include chloramphenicol 0.5 % eye drops, tobramycin 0.3% eye drops, naphazoline (Clear Eyes) 0.01% eye drops (Pharmacy Only Medicine) and pilocarpine (Isopto Carpine) 4% eye drops. Chloramphenicol eye drops are the main focus of the advice for children as these could theoretically be administered at a dose that would exceed the recommended threshold for boron if used at the maximum dose currently listed in the New Zealand data sheet. Tobramycin drops, if used at the maximum dose in the data sheet, could also exceed the threshold, however they are not widely prescribed for children. The Clear Eyes brand of naphazoline drops should not be used in children aged under 12 years and pilocarpine drops are rarely required in children and usually only with specialist input.
Chloramphenicol drops given as one drop four times a day for the treatment of bacterial conjunctivitis is unlikely to exceed the threshold for boron in the under two years age group. This dosing regimen is
endorsed by the Royal College of Ophthalmologists in the UK. Chloramphenicol ointment does not contain boron and therefore is a suitable alternative but it can be difficult to administer in children. Pressure applied to the tear duct during administration may help to reduce systemic absorption of boric acid from eye drops, however, this may be impractical in a child.
The threshold for safety concerns for boron in older children is 3 mg/day in children aged 2- 12 years, 7 mg/day in children aged 12- 18 years and 10 mg/day in adults; these thresholds would not be exceeded if using recommended doses of currently available boron-containing medicines.
Paper of the week: Common skin complaints in primary care
This week, we once again depart from our paper of the week to bring you another podcast from The Curbsiders, a group of doctors, clinical educators and medical students from across the United States. The group produces regular audio episodes, approximately one hour in length, with a relaxed and entertaining approach, where they "curbside" the experts to discuss a topic and provide key clinical messages and practice changing knowledge.
In this episode, Common Skin Complaints in Primary Care, the hosts ("Dermsiders") interview Dr Helena Pasieka, Director of Dermatology at MedStar Washington Hospital and Georgetown University Hospital, Washington D.C. She is presented with a number of dermatological cases and then discusses some good clinical tips and tricks (e.g. the “fluff test” for tinea versicolor – we refer to it as pityriasis versicolor) to use when diagnosing and managing all those potentially confusing rashes, lumps, bumps and terrible looking toenails. If you want to skip the preamble, Dr Pasieka begins addressing the dermatological cases from around 8 minutes. Note, the “KOH” test they refer to is when skin scrapings or nail clippings are examined using potassium hydroxide (KOH) preparation and stained with blue or black ink. N.B. This podcast series does contain some advertisements from sponsors.
If you don't have time to listen to the podcast, the webpage has a great summary, including common skin complaint pearls (of wisdom), notes and images.
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