Often used for:
Seizures, procedural sedation
What is phenobarbital?
Phenobarbital is a barbiturate used to treat seizures and provide sedation. It may also be used for anxiety, neonatal opioid withdrawal, or hyperbilirubinemia. It can be administered in the clinic, hospital, or at home.
Phenobarbital at home
- May be taken with or without food; take with food if stomach upset occurs.
- Tablets: swallow as directed; liquid: shake well and use the provided measuring device.
- Take doses exactly as prescribed to maintain consistent blood levels.
- If a dose is missed and the next dose is due in 4 hours or more, give the missed dose; otherwise skip it. Do not double doses.
- Store at room temperature in a dry place.
Possible side effects
- Low blood pressure
- Increased excitement, agitation, or hyperactivity
- Depressed mood
- Shortness of breath or slow breathing
- Fatigue or weakness
- Nausea and vomiting
- Loss of appetite (especially in neonates)
- Headache
- Constipation
- Dizziness or confusion
- Sleep problems or nightmares
- Slow heart rate
- Temporary liver function changes
- Allergic reactions (rash, hives, itching, runny nose, fever, chills, headache, muscle ache, shortness of breath, coughing, tightness in throat, swelling of face or neck, dizziness, low blood pressure, chest pain)
- Not all patients experience these effects. Report all symptoms.
Tips for patients and families
- Discuss all medicines with the care team; phenobarbital has many interactions.
- May be habit-forming with long-term use; share concerns with the care team.
- Blood levels may be monitored; follow lab instructions carefully.
- Use caution with activities requiring alertness until the medicine's effects are known.
- Monitor mood changes and report worsening depression or anxiety.
- Do not stop the medicine abruptly without medical guidance.
- Use additional birth control as hormone-based methods may be less effective.
- Inform the care team if sexually active, pregnant, or breastfeeding.
