Zybancpipextractc.pdf

EXTRACT FROM FORTHCOMING ISSUE
The Committee on Safety of Medicines has reviewed the available data on the safety of
Zyban. Doctors should be aware of the known adverse effects, particularly the risk of
seizures (1 in 1000 patients) and are reminded to follow carefully the guidelines for
prescribing of Zyban which are in the product information. The Medicines Control
Agency and the Committee on Safety of Medicines will continue to closely monitor
reports of adverse reactions to Zyban.
The following article will appear in the March 2001 issue of Current Problems in
Pharmacovigilance. We are distributing this article additionally to GPs and smoking
cessation specialists as it contains important prescribing information.
If further information is required, contact the Medicines Control Agency on
020 7273 0000
tZyban [bupropion (amfebutamone)] - safety reminder
Bupropion is contraindicated in individuals with a previous or current seizure disorder. Bupropion was licensed in June 2000 as an aid to smoking cessation in combination withmotivational support in nicotine-dependent individuals aged 18 or more. The initial dose is150mg to be taken daily for three days, increasing to 150mg twice daily. The maximumsingle dose should not exceed 150mg and the total daily dose should not exceed 300mg.
It is estimated that approximately 276,000 people have received bupropion in the UK in thefirst six months of marketing. Up to 12 February 2001, a total of 3,457 reports of suspectedadverse reactions have been received via the Yellow Card Scheme in the UK.
The most frequently reported suspected reactions are those known to occur commonly (i.e.
>1/100 individuals treated) and include: • CNS reactions (e.g. insomnia, dizziness, depression, tremor, anxiety, agitation) • skin and hypersensitivity reactions (e.g. urticaria, rash pruritus) Other less frequently reported recognised reactions include angioedema, chest pain,increased blood pressure and rarely reported reactions include erythema multiforme andStevens-Johnson syndrome.
It is important to note that the suspected reactions are not necessarily caused by the drugand may relate to other factors such as nicotine withdrawal, other illnesses or othermedicines taken concurrently.
There have been 18 reports of suspected adverse reactions to bupropion which had a fataloutcome. The contribution of bupropion to these fatal cases is unproven and in the majorityof cases the individual’s underlying condition may provide an alternative explanation.
Seizures
Bupropion is associated with a dose-related risk of seizure with an estimated incidence of
approximately 0.1% (1/1,000) based on doses up to the maximum recommended daily dose
of 300 mg daily. There have been 74 reports in the UK of seizures suspected as being
associated with the use of bupropion. In approximately half of the reports, individuals had
either a past history of seizure or risk factors for their occurrence.
Prescribers are reminded that bupropion:
• is contraindicated in individuals with a current seizure disorder or previous history of seizures and those with a current or previous diagnosis of bulimia or anorexia nervosa.
• should be administered with extreme caution in individuals with conditions which predispose to a lowered seizure threshold (including a history of head trauma andcentral nervous system tumour).
• should be administered with caution in individuals who are concurrently taking medicines known to lower the seizure threshold (including antipsychotics,antidepressants, theophylline, systemic steroids).
• treatment should be discontinued and not recommenced in individuals who have Co-prescribing:
• bupropion inhibits metabolism by cytochrome P450 2D6. Caution is therefore advised when other medicines predominantly metabolised by this enzyme are co-administered.
These include certain antidepressants (e.g. paroxetine), antipsychotics (e.g. risperidone),beta-blockers and Type 1C antiarrhythmics (e.g. propafenone, flecainide).
Full prescribing information can be found in the SPC.
As with all new drugs, the safety of bupropion remains under close review. Please
report all suspected adverse reactions through the Yellow Card Scheme.

Source: http://www.adr.org.uk/zybancp1.pdf