Hi Thanks for posting your query on HCM. Incomplete data like what is the purpose of using Venlafaxine, I mean what is your problem for which it is being prescribed??? I appreciate your doubt about the possible similarity between Venlafaxine and Amphetamine. Venlafaxine is an important drug used in the treatment of depression, painful nerve conditions like post herpetic neuralgia, trigeminal neuralgia, etc. Its use is associated with increased heart rate, BP, sleep disturbances, sexual dysfunctions, and constipation. On the other hand, Amphetamine is nervous system stimulant drug, it is used only in the treatment of attention deficit hyperactivity disorder and narcolepsy however most of the time it is abused for its effects like euphoria, alertness, increased physical activity. The side effects produced by Amphetamine are quite similar but in increased intensity like sleep disturbances, loss of appetite, increased heart rate and BP, palpitations, hallucinations and delusions. Yes, it gives a false positive test for PCP. Hope the information given above have cleared your doubts. Regards.