phenterminPhentermin is one of two drugs in the Fen-phen anti-obesity medication, the other being fenfluramine or dexfenfluramine. Phentermin comes in tablets and extended-release capsules. It usually is taken as a single daily dose in the morning or three times a day 30 minutes before meals. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take phentermin exactly as directed. The anorectic drug phentermin produces dose-related toxic effects on brain dopamine (DA) neurons in animals. Until recently, phentermin was widely used in combination with fenfluramine for purposes of appetite suppression and weight loss. With the recent withdrawal of fenfluramine from the market, many people have begun combining phentermin with fluoxetine, a serotonin reuptake inhibitor which also produces mild anorectic effects. Fluoxetine, in addition to inhibiting serotonin reuptake, inhibits hepatic mixed function oxidase, which plays an important role in the metabolic degradation of amphetamines. The purpose of the present study was to assess the effects of fluoxetine on the anorectic and DA neurotoxic effects of phentermin in mice. Phentermin, in combination with fluoxetine, produced greater reductions in food intake and body weight than phentermin alone. The phentermin/fluoxetine combination also produced greater long-term reductions in brain DA levels than phentermin alone, likely reflecting greater DA neurotoxicity of the drug combination. Brain concentrations of phentermin were also found to be higher in animals pretreated with fluoxetine. These findings indicate that fluoxetine potentiates both the anorectic and DA neurotoxic effects of phentermin, probably by increasing phentermin brain levels. The clinical significance of these findings remains to be ascertained.
|