Prescriber Update is a quarterly medical safety publication issued by Medsafe, the New Zealand Medicines and Medical Devices Safety Authority. It is intended for healthcare professionals to communicate emerging safety signals, drug risks, regulatory updates, and clinical advice.
This issue (December 2025) contains 73 pages and includes:
- Feature articles on specific drug safety topics
- A summary of recent safety communications
- An end-of-year knowledge quiz
- Updates from the Medicines Adverse Reactions Committee (MARC)
- Recent approvals of new medicines and indications
- Updated data sheets with new safety information
Main Articles & Key Messages
a) Intestinal Angioedema with ACE Inhibitors and ARBs
- Risk: ACE inhibitors and ARBs can cause angioedema not only in the face and airways but also in the intestines, which is often under-recognized.
- Mechanism: ACE inhibitors cause bradykinin buildup; ARBs have a lower risk but can still cause angioedema via an unknown mechanism.
- Presentation: Symptoms include abdominal pain, diarrhea, nausea, vomiting, and imaging may show bowel wall thickening or ascites.
- Management: Suspect intestinal angioedema in patients on ACE inhibitors/ARBs with unexplained GI symptoms; discontinue the drug if confirmed.
- NZ Data: Between 2010–2025, 278 ACE inhibitor and 26 ARB angioedema cases were reported, but no intestinal cases yet.
b) Paracetamol-Induced High Anion Gap Metabolic Acidosis (HAGMA)
- Risk: Long-term therapeutic use of paracetamol, especially in patients with severe illness, malnutrition, alcoholism, or on flucloxacillin, can cause pyroglutamic acidosis.
- Mechanism: Glutathione depletion leads to accumulation of pyroglutamate (5-oxoproline).
- Diagnosis: Suspect in patients with metabolic acidosis and risk factors; measure urinary 5-oxoproline.
- Management: Discontinue paracetamol promptly and follow local treatment guidelines.
- NZ Data: Four cases reported, three with concomitant flucloxacillin.
c) Allergic Reactions with Andrographis paniculata
- Risk: Andrographis-containing natural health products (marketed for immune support) can cause serious allergic reactions, including anaphylaxis.
- Advice: Healthcare professionals should ask patients about natural health product use when evaluating hypersensitivity reactions. Patients should stop using andrographis products if a reaction occurs.
d) Triple M Overlap Syndrome with Immune Checkpoint Inhibitors (ICIs)
- Syndrome: Myocarditis, myositis, and myasthenia gravis can occur together (“Triple M”) in patients on ICIs (e.g., pembrolizumab, nivolumab).
- Severity: High morbidity and mortality (~40% in-hospital mortality).
- Recommendation: If one of these conditions is suspected in a patient on an ICI, screen for the others. Prompt recognition and treatment are critical.
- NZ Data: Three cases reported.
Quarterly Safety Communications Summary
The table lists recent alerts and letters, including:
- Estradot patches: Quality and efficacy concerns
- Paxlovid: Use in severe renal impairment
- Topiramate: New pregnancy exposure prevention measures
- Valproate: Updated pregnancy risks (lower birth weight)
- Risperdal and Ribomustin: Product discontinuations
Prescriber Update Quiz 2025
A 10-question quiz tests knowledge on topics such as:
- Contraindications for Contrave
- Timing of fluoroquinolone-induced tendon rupture
- GLP-1 agonists and renal injury risk
- Colchicine toxicity and interactions
- Paracetamol-induced HAGMA mechanism
- Methotrexate contraception timelines
(Answers provided on page 72)
MARC’s Remarks (September 2025 Meeting)
Highlights from the Medicines Adverse Reactions Committee:
- GLP-1 agonists and oral contraceptives: Insufficient evidence to update data sheets.
- Intestinal angioedema with ACE inhibitors/ARBs: Recommended data sheet updates.
- Beta-2 agonists and seizures: No clear causal association found; data sheet consistency needed.
Gathering Knowledge from Adverse Reaction Reports
Presents real NZ case reports, such as:
- Goserelin + finasteride: Cardiac failure
- Atorvastatin + fusidic acid: Rhabdomyolysis (contraindicated combination)
- Botulinum toxin: Tinnitus, facial paralysis, hearing loss
- Semaglutide: Small bowel obstruction
- Terbinafine + fluoxetine: Mood changes, suicidal ideation
Recent Approvals & New Indications
Lists newly approved active ingredients and new therapeutic indications:
- New actives: e.g., Vanzacaftor (cystic fibrosis), Mavacamten (cardiomyopathy), Anifrolumab (lupus)
- New indication: Nicorette Quick Mist for nicotine vaping dependence
Recent Data Sheet Updates
Table of updated safety information, including:
- Abemaciclib: Lactation warning, erythema multiforme
- Atomoxetine: Serotonin syndrome risk, bruxism
- Colchicine: Narrow therapeutic index, toxicity warnings
- MMR vaccine: Contraindicated with immunosuppressive therapy
- Semaglutide: Hypotension, pen disposal advice
- Valproate: Lower birth weight risk in pregnancy
Editorial and Administrative Information
- Published by Medsafe, Ministry of Health, New Zealand
- Editorial team and medical advisors listed
- Encourages adverse reaction reporting via the Medsafe website
- Available under a Creative Commons license
Summary for Healthcare Professionals:
This issue emphasizes lesser-known drug risks (intestinal angioedema, paracetamol acidosis, Triple M syndrome) and reinforces monitoring and reporting responsibilities. It combines clinical guidance, regulatory updates, and case-based learning to enhance patient safety in New Zealand.
