Luvox is the most recent of the SSRI's to become available in this country. It was recently approved by the FDA for the treatment of obsessive-compulsive disorder (OCD), and has not been officially approved in this country for the treatment of depression. However, it is also an antidepressant, and is probably no less effective than the other SSRI's in treating depression and no better than the other SSRI's at treating OCD.
Luvox's chemical name is fluvoxamine, suggesting its chemical similarity to Prozac, or fluoxetine. Although they are both SSRI antidepressants, however, they otherwise not terribly similar. Luvox does not have the long half-life of Prozac, it is not as activating, it is metabolized by a different liver enzyme system, and does not have active metabolites.
Luvox has been available in Europe, where it is primarily used as an antidepressant, almost as long as Prozac, but we have less experience with it in this country.
In my experience, Luvox is less activating than Prozac, but not as sedating as Paxil. Because it was the most recent to be released of the SSRI's it is less often used as a first-line agent, but it appears to be a useful addition to our armormentarium. In particular, I have found Luvox to be effective in some patients who have failed multiple other antidepressants. However, it is well known individuals vary in their reaction to individual SSRI's, and this could probably be said of the others as well.
Solvay, the company which makes Luvox, is claiming it is less likely to cause sexual difficulties such as delayed ejaculation, based on some research reports. They suggest this is due to its high specificity for blocking reuptake of serotonin over dopamine. If true, Luvox would be theoretically more likely to cause the tiredness and lethargy which can occur as a result of "dopaminergic downregulation." I am not sure I am convinced I have seen either of these effects in clinical practice.
Fluvoxamine is an inhibitor of several liver enzyme systems (P450 1A2, 2C9, and 3A4). This may raise blood levels of certain other drugs such as warfarin (coumadin), theophylline, propranolol, and some benzodiazepine tranquilizers (Xanax, Valium, and others). Thus the doses of these other drugs may have to be decreased, and side effects must be carefully monitored. Luvox itself is metabolized by the 2D6 system, so its blood level will be raised if Prozac is taken concurrently.
Like all SSRI's, Prozac can cause the Serotonin Syndrome if mixed with other agents which increase serotonin.