phenelzine sulfate: clinical use

Prescribing considerations

• Confirm that the patient can understand and follow MAOI food restrictions and will check all prescribed and non-prescription products.
• Switches to or from an MAOI are complex, should involve a mental-health specialist and generally should not use cross-tapering.
• Avoid abrupt withdrawal because a severe withdrawal syndrome can occur.
• Review planned surgery or major dentistry in advance because the selected SmPC requires phenelzine withdrawal before elective procedures.
• Use particular caution with agitation, cardiovascular disease, epilepsy, blood dyscrasias, porphyria, diabetes, diuretics, schizophrenia, bipolar illness or concurrent ECT.

Contraindications and cautions

• Hypersensitivity to phenelzine or an excipient
• Phaeochromocytoma, cerebrovascular disease or congestive heart failure
• Current or previous liver disease, or abnormal liver-function tests
• Manic phase
• Use with other MAOIs, other antidepressants, 5-HT1 agonists or dibenzazepine derivatives
• Use with guanethidine, dextromethorphan, alcohol, narcotic analgesics or other central nervous system depressants
• Elective surgery under the circumstances specified in the product information

Monitoring

• Check blood pressure frequently and assess for pressor responses, palpitations and recurrent headache.
• Assess postural blood pressure and symptoms of orthostatic hypotension, especially in older people.
• Monitor depression, suicidal thinking and behavioural change closely during early treatment and after treatment changes.
• Watch for manic switching, excessive stimulation, serotonin toxicity and clinically important food or medicine interactions.
• Consider hyponatraemia if drowsiness, confusion or seizures develop.

Clinical pharmacology

Phenelzine is a hydrazine, irreversible, non-selective MAO inhibitor. Its antidepressant action is attributed to increased availability of monoamines, while prolonged biological activity reflects irreversible enzyme inactivation; metabolism is primarily by acetylation.

Formulation and product differences

• The selected SmPC covers orange, round, film-coated tablets marketed under Nardil and Phenelzine names; no formulation difference between those names is described.
• The coating contains sunset yellow and carmine. The product requires refrigerated storage, with short unavoidable periods outside refrigeration permitted.

Tablet

Route: Oral

Strengths: 15 mg