Epilepsy Ontario :: Bupropion (Zyban®) & Seizures

Bupropion (Zyban®) & Seizures

Bupropion, classified by Health Canada as an antidepressant, is available in Canada under the brand names Zyban® and Wellbutrin® SR. Introduced in May 1998, Wellbutrin® SR is used to treat depression. Zyban® (bupropion hydrochloride), introduced in August 1998, is used to help stop smoking.

GlaxoSmithKline, the Canadian manufacturer, released statements about its safety to health care professionals in July 2001, and to the general public in September 2001.

Although bupropion is "generally well tolerated", the most common side effects of bupropion are dry mouth and difficulty sleeping. Others may include nausea, constipation, headache, shakiness and an altered sense of taste. Other reactions may be associated also with stopping smoking: difficulty concentrating, dizziness, confusion, anxiousness, agitation, irritability, depression, or rarely, very marked mood changes. High blood pressure, sometimes severe, has been reported in patients taking Zyban® alone and in combination with nicotine replacement therapy (nicotine patch). Chest pain, possibly heart related, an increase in heart rate and, rarely, fainting have also been reported.

Approximately 1 person per 1000 taking standard doses of bupropion may have a seizure. The risk may increase with specific medical conditions or while taking other medications or alcohol.

Factors which may increase the risk for seizures:

having a seizure disorder (epilepsy) or a history of seizures;
currently taking Wellbutrin® SR tablets;
having a serious head injury;
having a central nervous system tumour;
having, or having had, an eating disorder (anorexia nervosa or bulimia);
drinking alcohol, especially in excess;
taking benzodiazepine drugs and abruptly stopping;
treating diabetes with insulin or hypoglycemics;
having liver impairment;
using of over the counter stimulants or anorectics (appetite suppressants);
having an addiction to opiates, cocaine, or stimulants;
using medications known to lower the seizure threshold (antidepressants, antipsychotics, lithium, theophylline, systemic steroids, quinolone antibiotics, antimalarials).

The seizure risk may be reduced by taking no more than 150 mg (1 pill) at a time, and, if taking 2 daily doses of 150 mg each (2 pills per day), ensuring that doses are taken at least 8 hours apart.

Anyone who experiences a seizure while taking bupropion should go to a hospital or doctor immediately and stop taking the drug.Bupropion should not be taken:

with a monoamine oxidase (MAO) inhibitor;
with thioridazine (Mellaril®), if taken within the past 14 days, or;
if allergic to bupropion or any of the ingredients in the tablets.
(Allergic reactions may include skin rash, difficulty breathing, itching, hives, chest pain, swelling of the mouth or face, or anaphylactic reactions. If these symptoms occur, stop taking bupropion immediately and contact your doctor.)Carbamazepine, phenobarbital and phenytoin may reduce the plasma levels of bupropion. In addition bupropion may interact with other medications.

More Information

GlaxoSmithKline Inc.
http://ca.gsk.com/HealthInfo/hcp/2001_07_03_buproprion.pdf
http://ca.gsk.com/HealthInfo/patient/2001_09_24_ZYBANPAfinal.pdf