Nembutal Side Effects

Generic name: pentobarbital

Medically reviewed by Drugs.com. Last updated on Jul 10, 2025.

Note: This document provides detailed information about Nembutal.

Applies to pentobarbital: parenteral solution for injection Side Effects associated with pentobarbital. Some dosage forms listed on this page may not apply specifically to the brand name Nembutal.

Applies to pentobarbital: parenteral solution for injection.

Side effects include:

Somnolence reported in up to 3% of patients; less common adverse effects reported in <1% of patients include agitation, confusion, hyperkinesia, ataxia, CNS depression, nightmares, nervousness, psychiatric disturbance, hallucinations, insomnia, anxiety, dizziness, thinking abnormalities, hypoventilation, apnea, bradycardia, hypotension, syncope, nausea and vomiting, constipation, headache, injection site reactions, hypersensitivity reactions (angioedema, skin rash, exfoliative dermatitis), fever, liver damage, megaloblastic anemia (following chronic use).

For healthcare professionals

Applies to pentobarbital: compounding powder, injectable solution, oral capsule, oral elixir, rectal suppository.

Nervous system adverse events

• Common (1% to 10%): Somnolence
• Uncommon (0.1% to 1%): Ataxia, central nervous system (CNS) depression, dizziness, hyperkinesia, syncope
• Frequency not reported: Headache^[Ref]

Psychiatric

• Uncommon (0.1% to 1%): Abnormal thinking, agitation, anxiety, confusion, dizziness, hallucination, nervousness, nightmares, psychiatric disturbance^[Ref]

Gastrointestinal

• Uncommon (0.1% to 1%): Constipation, nausea, vomiting^[Ref]

Respiratory

• Uncommon (0.1% to 1%): Apnea, hypoventilation^[Ref]

Cardiovascular

• Uncommon (0.1% to 1%): Bradycardia, hypotension^[Ref]

Hypersensitivity

• Frequency not reported: Angioedema, hypersensitivity reactions^[Ref]

Dermatologic

• Frequency not reported: Exfoliative dermatitis, skin rashes^[Ref]

Hematologic

• Frequency not reported: Megaloblastic anemia^[Ref]

Megaloblastic anemia occurred with chronic phenobarbital use.^[Ref]

Hepatic

• Frequency not reported: Liver damage^[Ref]

Other

• Frequency not reported: Fever^[Ref]

Local

• Frequency not reported: Injection site reactions^[Ref]

See also:

Further information

Nembutal side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer