EUTONYL
Clinical safety rating: caution
Comprehensive clinical and safety monograph for EUTONYL (EUTONYL).
Irreversible monoamine oxidase inhibitor (MAOI) selective for MAO-B at low doses, increasing synaptic concentrations of dopamine and phenylethylamine; at higher doses, also inhibits MAO-A.
| Metabolism | Hepatic metabolism, primarily via CYP2C19 and CYP2E1; undergoes N-dealkylation to desmethylselegiline and amphetamine metabolites. |
| Excretion | Renal: ~50-70% as unchanged drug and metabolites; fecal: ~30-50% via biliary elimination. |
| Half-life | Terminal elimination half-life of 1-2 hours (short half-life; may require multiple daily doses for sustained effect). |
| Protein binding | ~20-30% bound to albumin. |
| Volume of Distribution | 1-2 L/kg (indicates extensive extravascular distribution, primarily in tissues). |
| Bioavailability | Oral: ~50-70% (first-pass metabolism); intravenous: 100%. |
| Onset of Action | Oral: 30-60 minutes; intravenous: 5-10 minutes. |
| Duration of Action | 4-6 hours (shorter duration of action relative to half-life due to rapid distribution). |
10 mg orally twice daily; maximum 60 mg/day.
| Dosage form | TABLET |
| Renal impairment | Contraindicated in severe renal impairment (GFR <30 mL/min). No adjustment recommended for mild to moderate impairment (GFR 30-89 mL/min). |
| Liver impairment | Contraindicated in Child-Pugh class C. For Class A or B, reduce dose by 50% (start 5 mg orally twice daily). |
| Pediatric use | Not recommended for use in children; efficacy and safety not established. |
| Geriatric use | Initiate at 5 mg orally twice daily due to increased sensitivity; monitor for orthostatic hypotension and anticholinergic effects. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for EUTONYL (EUTONYL).
| Breastfeeding | Pargyline is excreted into human breast milk; however, the milk-to-plasma (M/P) ratio is not established. Based on other MAOIs, low levels are expected. However, due to potential for serious adverse reactions in nursing infants (e.g., hypertensive crisis, serotonin syndrome), breastfeeding is not recommended during therapy. Consider alternative agents. |
| Teratogenic Risk | Eutonyl (pargyline) is a monoamine oxidase inhibitor (MAOI) with limited human pregnancy data. Animal studies have shown embryotoxicity and teratogenicity at high doses. In the first trimester, there is a potential risk of congenital malformations, particularly cardiovascular defects, based on other MAOIs. In the second and third trimesters, use may be associated with fetal growth restriction, preterm birth, and neonatal withdrawal symptoms (irritability, tremors). Avoid use during pregnancy unless no safer alternative exists. |
■ FDA Black Box Warning
WARNING: Hypertensive crisis (tyramine reaction) is a serious risk; patients must avoid tyramine-rich foods and certain medications.
| Serious Effects |
Concomitant use with SSRIs, SNRIs, TCAs, MAOIs, or other serotonergic drugs; pheochromocytoma; severe renal/hepatic impairment; uncontrolled hypertension; concurrent use with dextromethorphan, bupropion, or sympathomimetics.
| Precautions | Risk of hypertensive crisis with tyramine ingestion; contraindicated with serotonergic drugs (risk of serotonin syndrome); may cause orthostatic hypotension; dietary restrictions required. |
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| Fetal Monitoring | Monitor maternal blood pressure, heart rate, and symptoms of hypertensive crisis (severe headache, palpitations, chest pain). Fetal monitoring should include serial ultrasound for growth and amniotic fluid volume assessment. Evaluate for fetal distress via nonstress test or biophysical profile in third trimester. Neonates should be observed for withdrawal symptoms and hypertensive effects. |
| Fertility Effects | Pargyline may impair fertility in both males and females due to inhibition of monoamine oxidase affecting hormonal regulation and sexual function. In males, reported ejaculatory dysfunction and decreased libido; in females, possible menstrual irregularities. These effects are typically reversible upon discontinuation. |