Note: This document contains side effect information about phenelzine. Some of the dosage forms listed on this page may not apply to the brand name Nardil.
Applies to phenelzine: oral tablet
Oral route (Tablet)
Antidepressants increased the risk of suicidal thinking and behavior in children, adolescents, and young adults in short-term studies with major depressive disorder (MDD) and other psychiatric disorders. Short term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond age 24, and there was a reduction in risk with antidepressants compared to placebo in adults aged 65 and older. This risk must be balanced with the clinical need. Monitor patients closely for clinical worsening, suicidality, or unusual changes in behavior. Families and caregivers should be advised of the need for close observation and communication with the prescriber. Not approved for use in pediatric patients.
Along with its needed effects, phenelzine (the active ingredient contained in Nardil) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur while taking phenelzine:
Some side effects of phenelzine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Applies to phenelzine: oral tablet
The most important adverse event reported is hypertensive crisis, which has been associated with intracranial bleeding and has been fatal.
Common (1% to 10%): Dizziness, drowsiness, headache, hyperreflexia, myoclonic movements, tremors
Uncommon (0.1% to 1%): Convulsions, palilalia, paresthesia, peripheral neuritis
Rare (0.01% to 0.1%): Acute dystonic reaction, ataxia, coma, neuroleptic malignant syndrome (occasionally fatal), sensorimotor peripheral neuropathy, shock-like coma, speech blockade, transient respiratory and cardiovascular depression following ECT
Frequency not reported: Intracranial bleeding/fatal intracranial bleeding, occipital headache/occipital headache which may radiate frontally
Common (1% to 10%): Anorgasmia, hypersomnia, hypomania, insomnia, sleep disturbances
Uncommon (0.1% to 1%): Agitation, behavioral changes, confusion, euphoria, frank psychosis, hallucinations, nervousness, vivid nightmares
Rare (0.01% to 0.1%): Acute anxiety reaction, delusional parasitosis, manic reaction, precipitation of schizophrenia, toxic delirium
Frequency not reported: suicidal behaviors, suicidal ideation
Common (1% to 10%): Constipation, dry mouth, gastrointestinal disturbances, nausea, vomiting
Common (1% to 10%): Anorgasmia, ejaculatory disturbances, impotence, sexual disturbances
Uncommon (0.1% to 1%): Delayed ejaculation, difficulty in micturition, urinary retention
Common (1% to 10%): Adverse effects on driving ability, fatigue, weakness
Uncommon (0.1% to 1%): Jitteriness, withdrawal/withdrawal syndrome
Rare (less than 0.1%): Fever associated with increased muscle tone, hyperpyrexia, malaise
Withdrawal may be associated with nausea, vomiting, and malaise.
Withdrawal syndrome occurred after abrupt drug discontinuation, and generally started after 24 to 72 hours; signs/symptoms varied from vivid nightmares and agitation to frank psychosis and convulsions. The withdrawal syndrome generally responded to reinstitution of low dose therapy, followed by cautious downward titration and discontinuation.
Common (1% to 10%): Edema, postural hypotension
Uncommon (0.1% to 1%): Arrhythmias
Rare (0.01% to 0.1%): Blood pressure changes, tachycardia
Frequency not reported: Bradycardia, constricting chest pain, hypertensive crisis, palpitation
Hyponatremia may be more likely to occur in older patients or in those with inappropriate secretion of antidiuretic hormone; this side effect should be considered in patients treated with antidepressants who present with confusion, convulsions, and/or drowsiness.
Hypermetabolic syndrome may resemble signs/symptoms of an overdose.
Common (1% to 10%): Weight gain
Uncommon (0.1% to 1%): Hypernatremia, increased appetite
Rare (0.01% to 0.1%): Hypermetabolic syndrome, metabolic acidosis
Frequency not reported: Hyponatremia
Common (1% to 10%): Blurred vision
Uncommon (0.1% to 1%): Glaucoma, nystagmus
Frequency not reported: Dilated pupils, photophobia
Common (1% to 10%): Twitching
Uncommon (0.1% to 1%): Muscle tremor
Rare (0.01% to 0.1%): Elevated creatine kinase levels, muscular rigidity
Frequency not reported: Neck soreness, neck stiffness
Common (1% to 10%): Elevated serum transaminases (without accompanying signs/symptoms)
Uncommon (0.1% to 1%): Elevated liver enzymes
Rare (less than 0.1%): Fatal progressive necrotizing hepatocellular damage, reversible jaundice
Uncommon (0.1% to 1%): Pruritus, purpura, rash/skin rash, sweating
Frequency not reported: Sweating with cold, clammy skin or fever
Uncommon (0.1% to 1%): Blood dyscrasias
Rare (less than 0.1%): Leucopenia
Uncommon (0.1% to 1%): Lupus-like illness
Rare (0.01% to 0.1%): Hypoxia, tachypnea
Rare (0.01% to 0.1%): Edema of the glottis
Rare (0.01% to 0.1%): Inappropriate secretion of antidiuretic hormone/ADH secretion
Medically reviewed by BestRx Medical Team Last updated on 1/1/2020.
Source: Drugs.com Nardil