Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.
Zoloft (Pfizer)
50 mg and 100 mg film coated tablets
Indication: depression
Sertraline is a serotonin (5-hydroxytryptamine, 5-HT) reuptake blocker. After absorption, it undergoes first pass hepatic metabolism before being extensively distributed. Metabolism also accounts for most of the elimination of sertraline, so a dose reduction is advised in patients with hepatic impairment. The cytochrome P450 system is involved in sertraline metabolism. The main metabolite has a longer half life than the parent compound (26 hours), but is inactive.
There are few published efficacy studies which compare sertraline to other antidepressants. Its efficacy may be similar to that of amitriptyline, but safety and efficacy have not been evaluated beyond 24 weeks' therapy.
The more common adverse effects are similar to those seen with other serotonin reuptake blockers and include gastrointestinal upset, somnolence and sweating. In pre marketing studies, 15% of patients discontinued treatment due to adverse effects.
There is little information on the use of sertraline in patients taking other psychiatric drugs. The clinical significance of recognised interactions is uncertain. Sertraline interacts with cimetidine, tolbutamide and warfarin. It should not be prescribed within two weeks of monoamine oxidase inhibitor therapy.
