Anorectic Phentermine can interact with certain drugs of other medicinal groups, including with antidepressants of the class of MAO inhibitors. Phentermine and MAO inhibitors belong to CNS stimulants and are synergistic drugs.
Phentermine has a small potential to suppress activity of monoamine oxidase enzyme. Phentermine can interact with MAO inhibitors, significantly increasing their therapeutic effect.
The results of clinical studies prove that risk of various adverse reactions significantly increases in interaction of Phentermine with MAO inhibitors, including:
Damage to the heart valves
Pulmonary arterial hypertension
A sharp increase in blood pressure.
In addition, Phentermine may cause increase in serotonin and dopamine concentrations in the body interacting with MAO inhibitors.
Thus, it is increased the likelihood of such symptoms of serotonin syndrome as:
- extremities tremor
- loss of coordination.
Because of high risk of drug interaction, it is contraindicated to take Phentermine simultaneously with MAO inhibitors, including Selegiline (Zelapar), Phenelzine (Nardil), Iproniazid (Marsilid), Rasagiline (Azilect), Isocarboxazid (Marplan) or Tranylcypromine (Parpromine).
To avoid drug interaction, it is recommended to start using Phentermine no earlier than two weeks after completion of a course of MAO inhibitors.