Medicines that normally reach your bloodstream in very small to moderate amounts are more likely to have significant interactions with grapefruit. This is because the effect of grapefruit can cause much larger amounts of the medicine to get into your bloodstream and cause side effects.
Safety of weight-loss drugs. Drugs for short-term use. Diethylpropion (Tenuate), phentermine (Adipex-P), benzphetamine (Didrex) and phendimetrazine are approved for only short-term use â generally less than 12 weeks. These drugs are classified as controlled substances because they have the potential to be abused.
In fact, Meridia, a weight-loss drug, is an SNRI. Another SNRI, Effexor, has no weight-loss properties, but it is an antidepressant. Fernstrom also adds that Prozac, Celexa, and Lexapro do not cause weight gain. However, in reading some of the forums and other literature, the reviews are very mixed on these drugs.