Publications
Published: December 2010
Answers to the Prescriber Update Quiz – December 2010
Prescriber Update 31(4): 35
December 2010
- There is evidence that these medicines are no more effective than maximum recommended doses of
paracetamol alone, and have the potential to cause more adverse reactions than paracetamol used at
recommended doses. Deaths related to overdose (intentional and unintentional) have occurred.
Prescribing restrictions failed to ensure these medicines were only used in patients for whom the
benefits outweigh the risks. Since these medicines were withdrawn in New Zealand, the FDA has also
required their withdrawal in the US, following new clinical trial evidence showing that
dextropropoxyphene causes QT interval prolongation at therapeutic doses.
- The ten most common are:
- Doxycycline
- Hydrochlorothiazide
- Amiodarone
- Piroxicam
- Chlorpromazine
- Trimethoprim/sulfamethoxazole
- Captopril
- Enalapril
- Bendroflumethiazide
- Carbamazepine
- Changing brands of fentanyl patches requires careful clinical monitoring as different brands may
not be interchangeable in an individual patient. A change in dose may be required for some patients.
- b) Class C(4) controlled drug
- True
- Finasteride (Fintral)
- Monitoring valproate plasma levels or adjusting the dose is unlikely to manage this interaction
given its extent and rapid onset. Prescribers are advised to avoid the use of carbapenem antibiotics
in patients taking sodium valproate.
- Acitretin is indicated for the treatment of severe psoriasis, disorders of keratinisation and
other dermatoses responsive to etretinate (Acitretin is an active metabolite of etretinate) whereas
isotretinoin is indicated to treat severe forms of nodulo-cystic acne which are resistant to
therapy.
- Any three of: clarithromycin, erythromycin, chloroquine, pentamidine, domperidone, cisapride,
haloperidol, chlorpromazine, methadone, terfenadine.
- Hypomagnesaemia
