According to The Doctor's People (the American newsletter founded by the late medical critic Dr Robert Mendelsohn and until recently edited by its co-founder, Vera Chatz), numerous Prozac users are in the process of suing Lilly, claiming that the drug caused suicidal and homicidal thoughts and actions.

In one case, a Prozac user killed five and wounded l2 others at the printing plant where he worked. In another, a 40 year old New York secretary claimed that she became "obsessed with dying" and began harming herself with whatever sharp implements she could find.

Although there was no evidence of "suicide ideation or activity," with Seroxat, says Chandler, SmithKline Beecham, to his knowledge, did not test for an increase in homicidal tendencies.

In keeping with US regulations (and American drug company caution), Lilly has published page after page of warnings about potential side effects of Prozac. Some l0 to l5 per cent of patients in initial clinical trials reported having anxiety and insomnia and a "significant number", particularly underweight patients, report significant weight loss or anorexia. About l0 per cent of patients in clinical trials reported anxiety as a side effect and almost 9 per cent, anorexia. In other words, l in l0 patients, experience the same symptoms from the drug that they are trying to treat. In one study, says Silverman in The Pill Book, l3 per cent of patients on the drug lost more than 5 per cent of their body weight.

Although there was no significant change in body weight in the 4000 test subjects who took Seroxat for a year, SmithKline Beecham warns that the most common side effect includes insomnia. Again, the drug can cause one of the symptoms that you are trying to treat.

Prozac has also been known to affect nearly every system of the body, including nervous, digestive, respiratory, cardiovascular, musculoskeletal, urogenital and skin and appendages. These side effects include, most commonly, visual disturbances, palpitations, mania/hypomania, tremors, symptoms of flu, cardiac arythmia, back pain, rashes, sweating, nausea, diarrhoea, abdominal pain, loss of sex drive. Less common effects include antisocial behaviour, double vision, memory loss, cataracts or glaucoma, asthma, arthritis, osteoporosis, stomach bleeding, kidney inflammation and impotence. According to The Pill Book, fluoxetine also, albeit infrequently, causes "abnormal dreams, agitation, convulsions, delusions and euphoria."

The side effects reported by SmithKline Beecham about Seroxat include nausea, somnolence (drowsiness), sweating, tremor, asthenia (loss of physical strength), dry mouth, and sexual dysfunction. And although the company boasts that this drug is not addictive, they recommend that patients be weaned off the drug gradually "as abrupt or sudden discontinuation may lead to symptoms such as disturbed sleep, irritability or dizziness". The company also warns that it shouldn't be used by patients with a history of mania.

Both drugs have side effects when taken with other psychoactive drugs. Prozac interacts with numerous other drugs and should not be taken with them. For instance, it may prolong the effects of benzodiazepines like Valium and increase the action of warfarin, used to treat blood clots, and digitalis preparation digoxin, for congestive heart failure and cardiac arrhythmias. Patients taking Prozac with tryptophan can become agitated with upset stomachs.

SmithKline Beecham warns that Seroxat should not be taken in combination with MAO inhibitors (or even two weeks after finishing treatment with them, and vice versa), oral anticoagulants, tryptophan, drugs affecting liver metabolizing enzymes, lithium, anticonvulsants and warfarin.