Secobarbital Side Effects

Medically reviewed by Drugs.com. Last updated on Feb 27, 2025.

Applies to secobarbital: injectable solution, oral capsule.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Some people using this medicine have engaged in activity such as driving, eating, walking, making phone calls, or having sex and later having no memory of the activity. If this happens to you, stop taking secobarbital and talk with your doctor about another treatment for your sleep disorder.

Stop using secobarbital and call your doctor at once if you have:

• unusual thoughts or behavior;

• new or worsening depression;

• confusion, hallucinations;

• anxiety, agitation; or

• thoughts of suicide or hurting yourself.

The sedative effects of secobarbital may be stronger in older adults.

Common side effects may include:

• drowsiness, feeling tired;

• "hangover" effect (drowsiness the day after a dose);

• headache, dizziness;

• memory problems;

• dry mouth;

• upset stomach; or

• feeling restless or excited (especially in children).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

See also:

For healthcare professionals

Applies to secobarbital: injectable solution, oral capsule.

Nervous system adverse events

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

Psychiatric

• Frequency not reported: Abnormal thinking, agitation, anxiety, confusion, dependence, excitement, hallucinations, insomnia, nervousness, nightmares, other complex behaviors, psychiatric disturbance, sleep driving^[Ref]

Other

• Frequency not reported: Fever, tolerance, withdrawal symptoms^[Ref]

Gastrointestinal

• Frequency not reported: Constipation, nausea, vomiting^[Ref]

Respiratory

• Frequency not reported: Apnea, hypoventilation^[Ref]

Hypersensitivity

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

Dermatologic

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

Cardiovascular

• Frequency not reported: Bradycardia, hypotension^[Ref]

Hematologic

• Frequency not reported: Megaloblastic anemia^[Ref]

Hepatic

• Frequency not reported: Liver damage^[Ref]

Local

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

Further information

Secobarbital 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