Agent	Adverse Reactions	Additional Comments
Antibiotics
Linezolid	Serotonin syndrome	Reversible MAOI; selectively inhibits MAO-A. Combination with MAOI produces toxic levels of serotonin.
Antidepressants
Other MAOIs	Hypertensive crisis	Increase risk for severe side effects; convulsions
SNRIs	Serotonin syndrome, hypertensive crisis	Severe hypertensive crisis and serotonin syndrome
SSRIs	Serotonin syndrome	Severe serotonin toxicity and strongly associated with fatalities.
TCAs
Clomipramine	Severe serotonin toxicity	Causes potent inhibition of serotonin and should never be combined with an MAOI
Other TCAs (e.g., cyclobenzaprine, carbamazepine, oxcarbazepine)	Possible serotonin toxicity	Combination therapy with MAOI + TCA can be used for severe TRD with caution. Never start the MAOI first; take at the same time as TCA or after beginning the TCA first. Low doses should be given for both and titrated to a tolerable dose
Cold Medications
Decongestant
Oxymetazoline	Hypertensive crisis	Over-the-counter α1-adrenoceptor agonist
Phenylephrine	Hypertensive crisis	Over-the-counter α1-adrenoceptor agonist
Cough suppressant
Dextromethorphan	Serotonin syndrome	Weak 5-HT reuptake inhibitor
Illicit Drugs
Ecstasy	Severe serotonin syndrome	Acts as a serotonin releaser; can cause severe, fatal serotonin toxicity
Methylene Blue	Serotonin syndrome	Potent, reversible MAOI
Synthetic analgesics / Opioids	Serotonin syndrome	Analgesics that are weak SRIs should be avoided. Safe analgesics to use include morphine, codeine, oxycodone, and buprenorphine
Fluphenazine	May prolong or intensify the hypotensive, anticholinergic, or sedative effects of either agent	Due to the potential for additive CNS and cardiovascular effects, MAOIs and phenothiazines should be used together cautiously
Cimetidine	May increase steady-state plasma concentrations of MAOI	Dose of MAOI may have to be reduced for the duration of cimetidine treatment