The Medicines Control Agency has issued a safety update statement for bupropion
(Zyban). It says that, while there are no new safety issues, it must be remembered
that bupropion is contraindicated in patients with previous or current seizure
disorder.
Between June this year, when the drug was launched, and October 31, there had
been 1,038 reports of suspected adverse reactions to bupropion via the “yellow
card” scheme. All reactions were listed in the summary of product characteristics.
There were 40 reports of seizures. In about half of these cases, the patient
had either a past history of seizure and/or risk factors for their occurrence,
the MCA says. However, the reporting rate of seizures was no greater than the
estimated incidence of 0.1 per cent. The MCA estimates that 150,000 patients
have received bupropion since its launch.
The agency adds that bupropion should be administered with extreme caution in
patients with conditions that predispose them to a lowered seizure threshold.
Other reported reactions included insomnia (125 reports), urticaria (110), nausea
(103), dizziness (100) and angioedema (94). Events such as depression, anxiety,
dry mouth and chest pain were also reported.
There had been 10 reports of suspected adverse reactions with fatal outcomes,
although the contribution that bupropion had made in any of these cases was
unproven. The statement can be found on the MCA’s website (http://www.open.gov.uk/mca/).