OBJECT DRUGS

MAO Inhibitors (nonselective):

• Furazolidone (Furoxone)
• Isocarboxazid
• Methylene Blue
• Phenelzine (Nardil)
• Tranylcypromine (Parnate)

PRECIPITANT DRUGS

Sympathomimetics:

• Amphetamines
• Atomoxetine (Strattera)
• Bupropion (Wellbutrin, etc.)
• Cocaine
• Diethylpropion (Tenuate, etc.)
• Dopamine
• Ephedrine
• Isometheptene (Midrin)
• Mazindol (Sanorex)
• Metaraminol (Aramine)
• Methylphenidate (Ritalin, etc.)
• Phendimetrazine (Bontril)
• Phentermine (Ionamin, etc.)
• Phenylephrine
• Pseudoephedrine (Sudafed, etc.)
• Tapentadol (Nucynta, etc.)

Comment:

Indirect acting sympathomimetics result in release of the increased stores of norepinephrine, and may result in severe hypertension, hyperpyrexia, seizures, arrhythmias and death in patients on nonselective MAO inhibitors (MAOI). Direct acting sympathomimetics such as epinephrine, isoproterenol and norepinephrine do not appear to interact as much, because they do not cause release of norepinephrine. Nonetheless, one should still be alert for increased pressor effects. Phenylephrine is a direct acting sympathomimetic, but it can also cause hypertensive reactions in patients on nonselective MAOI, because it is a substrate for intestinal and hepatic MAOI. Bupropion purportedly may increase the risk of a hypertensive reaction in patients on nonselective MAO inhibitors, and the combination is considered contraindicated in the bupropion product information. Although some patients with refractory depression have taken the combination of bupropion and nonselective MAOI without serious consequences, there is too little clinical information to suggest that the combination is safe.

Class 1: Avoid Combination

• Avoid: Avoid the sympathomimetics for at least 14 days (preferably 18-20 days) after stopping an MAOI.