Dutonin, an antidepressant, was launched with the claim that it is as effective as Prozac, but with far fewer side-effects. But the marketing men may have to do a rethink following new reports from the US that the drug could cause liver failure so severe as to result in a transplant or death.
The US drug regulator, the Food and Drug Administration, knows that the problem affects about 1 in 60,000 patients but, because of serious underreporting, recognises that the problem is much worse.
Patients with liver disease shouldn't take the drug, and doctors in the US have been put on the alert for warning signs such as jaundice, anorexia and gastrointestinal complaints.
Dutonin (nefazodone), called Serzone in North America, was heralded as a new kind of antidepressant when the FDA licensed it in 1994. Unlike SSRIs like Prozac that boost serotonin levels and tricyclics that block serotonin receptors, Dutonin is supposed to do both, as well as block the receptors called 5HT2, which are among those most likely to cause depression.
Despite the early claims of fewer side-effects than Prozac, 16 per cent of patients in a trial of 3496 patients had to discontinue treatment because of an adverse reaction. The most common reactions included nausea, dizziness, insomnia, asthenia (feeling weak) and agitation.
Other common side-effects have included sleepiness, dry mouth, constipation, blurred and abnormal vision, lightheadedness and confusion.
It can also be dangerous to take Dutonin with other drugs, especially antihistamines like Seldane and Hismanal, as the combination can increase blood drug levels to the point of being life-threatening.
When Dutonin was launched, doctors were not convinced that it was as effective as the SSRIs. They now have a further reason to pause before writing the prescription.