The edition · Clinical Pharmacology
Serotonergic and vasoactive drugs dominate reports of drug-associated RCVS
A VigiBase analysis of 1553 reversible cerebral vasoconstriction cases links them to triptans, ergots, SSRIs and cannabis, with onset in about nine days, and flags teprotumumab as a new signal. Also: repeated switching to a ustekinumab biosimilar, pharmacogenomic exposure in a multi-ethnic Asian population, benzodiazepine trends in England, and an FDA supplement for tirzepatide.
The edition in brief
A case–non-case analysis of the WHO VigiBase database found 1553 reports of reversible cerebral vasoconstriction syndrome (RCVS) and 735 of central nervous system vasculitis. RCVS was mainly associated with triptans, ergot derivatives, SSRIs and cannabis, with median onset 8.75 days; the strongest signal was teprotumumab (6 cases, adjusted reporting OR 60.2). CNS vasculitis was linked to pembrolizumab, nivolumab and propylthiouracil, with onset around five weeks. In thunderclap headache, the drug history is part of the diagnosis and withdrawal is part of treatment. A randomised trial in 453 psoriasis patients found three alternating switches between the ustekinumab biosimilar ABP 654 and the reference product gave equivalent drug exposure, efficacy and immunogenicity. In Singapore, 38 to 43% of patients received a pharmacogenomically actionable drug each year, and an estimated 18.4% could have had a prescription changed by pre-emptive testing; CYP2C19, CYP2D6 and SLCO1B1 dominated. Benzodiazepine prescribing in England fell 4.3% a year from 2020 to 2025, while clobazam rose. FDA's database lists a supplement to the tirzepatide (Mounjaro) application; its content is not stated.
Repeated switching to a ustekinumab biosimilar kept exposure equivalent
Stable patients on ustekinumab can be switched to the ABP 654 biosimilar, even repeatedly, without loss of exposure or response.
Pharmacogenomically actionable drugs reach 4 in 10 patients a year in Singapore
Watch the common gene–drug pairs — CYP2C19, CYP2D6, SLCO1B1 — when prescribing PPIs, clopidogrel, statins, codeine and tramadol.
Benzodiazepine prescribing in England falls, but clobazam rises
Keep deprescribing long-term benzodiazepines with a gradual taper, and avoid starting short-acting agents.
FDA lists a supplement to the tirzepatide (Mounjaro) application
An FDA supplement to the Mounjaro application has been listed; it changes nothing until the revised label is published.
The drug history in thunderclap headache
In thunderclap headache without haemorrhage, take a targeted drug history and avoid giving a triptan.
Drug-associated RCVS and CNS vasculitis have distinct culprits and timing
In suspected RCVS or CNS vasculitis, identify and stop the likely drug: serotonergic agents within days, checkpoint inhibitors or propylthiouracil over weeks.
Read the rest in the app
You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this one is waiting in it.
Scan to keep reading on your phone. No account needed to start.
Tomorrow morning, before your first patient
One edition a day for clinical pharmacology, written by the desk, every claim tied to its paper. Six minutes.
Get the app — free