OBJECT DRUGS

MAO Inhibitors (Nonselective):

• Linezolid (Zyvox)

MAO-B Inhibitors:

• Rasagiline (Azilect)
• Selegiline (Eldepryl, etc.)

PRECIPITANT DRUGS

Antidepressants, Tricyclic:

• Clomipramine (Anafranil)
• Imipramine (Tofranil, etc.)

Comment:

Linezolid appears to be a weak MAOI, but serotonin syndrome has been reported when it is combined with serotonergic agents such as clomipramine and imipramine. Selective MAO-B inhibitors theoretically should not interact with TCAs, but in some patients MAO-B inhibitors may become nonselective thus increasing the risk of serotonin syndrome. Rasagiline is metabolized by CYP1A2, so theoretically, patients on CYP1A2 inhibitors may be more likely to develop nonselective MAO inhibition due to rasagiline. (For a list of CYP1A2 inhibitors, see CYP 450 Table at front of book.)

Class 2: Use only if Benefit Felt to Outweigh Risk

• Use Alternative: If a TCA is given to patients on linezolid or MAO-B inhibitors, use a TCA other than clomipramine or imipramine. Avoiding amitriptyline, doxepin and desipramine would also be prudent. The product information for linezolid states that it should not be used with serotonergic agents unless the patient is closely observed for evidence of serotonin syndrome. Depending on the antibiogram, consider alternative antibiotics such as vancomycin or telavancin (Vibativ) for linezolid.
• Monitor: If any TCA is used with linezolid or an MAO-B inhibitor, monitor for evidence of serotonin syndrome (myoclonus, rigidity, tremor, hyperreflexia, fever, sweating, seizures, confusion, agitation, incoordination, and coma).