The concept of pharmahuasca and its relationship to ayahuasca is discussed. This novel binary system is extremely safe and effective when used responsibly, though some basic principles are essential for responsible use. Particular attention has been given to the potential hazards of enzyme inhibition as a mode of drug delivery, in addition to some factual information on monoamine oxidase (MAO) and its relationship to neurotransmission. Specific contraindications for these preparations are also discussed. Antidepressant medications, in particular, should not be combined with inhibitors of MAO under any circumstances.