The Medicines and Healthcare products Regulatory Agency (MHRA) has published Drug Safety Update Issue 5 (PDF).
This fifth issue includes the following drug safety advice articles:
- Recombinant human erythropoietins: new prescribing advice
- Rosiglitazone and pioglitazone: cardiovascular safety
- Dosulepin: measures to reduce risk of fatal overdose
- ACE inhibitors and angiotensin II receptor antagonists: not for use in pregnancy
- Short-acting β agonists: myocardial ischaemia
In addition, this issue contains hot topics focussing on potential side effects of varenicline and balancing of cardiovascular and gastrointestinal risks of NSAIDs. There is also a reminder to prescribers about the withdrawal of lumiracoxib and the risk of severe allergic reactions with strontium ranelate.
Action: Clinicians will find this publication to be a useful review of current issues in drug safety.
Toparimate (Topamax®) is growing in popularity for the prevention of migraine. This is a licensed indication but current Clinical Knowledge Summary (CKS) recommendations suggest that this drug should only be initiated by specialists.
A recent assessment conducted by the National Prescribing Service in Australia has supported this second line position and also provides some useful information regarding efficacy and side effects.
The NPS assessment concludes:
- Topiramate is an alternative migraine-prevention option for adults unable to take beta blockers or pizotifen
- Around 50% of patients using topiramate experienced paraesthesia
- Cognitive effects (cognitive slowing, language difficulties and difficulties with memory and concentration) are common (6% to 7%) and lead to treatment withdrawal in up to 3% of patients
- There is no evidence that topiramate is more effective than other migraine-prevention drugs
Action: Based upon these conclusions and the information provided in the CKS on Migraine, topiramate should be restricted to use in patients where beta-blockers and amitriptyline have proven to be ineffective or are not tolerated.
