Paroxetine (marketed in the UK as Seroxat and in the US as Paxil) is an antidepressant that has been blamed for causing chronic hepatitis. The drug, manufactured by Smithkline Beecham, is a selective serotonin reuptake inhibitor (SSRI), designed to treat depressive illnesses such as obsessive-compulsive disorder and panic disorders.
At least six cases of hepatitis related to the drug have been reported to the UK's drug regulator, the Committee on Safety of Medicines (CSM). Doctors at the Royal Liverpool University Hospital also have reported one case of a 54-year-old woman who developed chronic hepatitis after being on the drug for 17 months (BMJ, 1997; 314: 1387). Her liver had functioned well before starting treatment, and it eventually returned to normal after the drug was withdrawn.
This development should come as no great surprise, as liver problems have been associated with the drug for some time. At least 54 cases have been reported to the CSM, and warnings have been included both in the UK Compendium of Data Sheets and the American Physicians' Desk Reference.
It seems to be a hard drug to tolerate. In several studies, up to 20 per cent of patients had to come off the drug because of some side effect. Common side effects - occurring in at least 5 per cent of all users, and at least twice that of placebo - include nausea, somnolence, sweating, tremor, dry mouth, insomnia, sexual dysfunction, dizziness, constipation, diarrhoea, and decreased appetite.
Rare side effects reported in early trials have included mania, seizures, suicidal tendencies and abnormal bleeding.
As with most antidepressants, paroxetine should not be taken with a monoamine oxidase inhibitor (MAOI). When they have been taken in combination, the effects can sometimes be fatal, and include hyperthermia and extreme agitation, leading to delirium and coma.