II. Indications
III. Contraindications
- Porphyria
- Phenobarbital Hypersensitivity
IV. Mechanism
-
Barbiturate with 2 active metabolites
- Phenobarbital
- Phenylethylmalonamide (PEMA)
- Raises Seizure threshold
V. Dosing: Essential Tremor (Adults)
- Start 12.5 mg to 25 mg orally at bedtime
- Titrate weekly by 50 mg/day, up to 250 mg/day divided once to twice daily
- Maximum: 750 mg/day
VI. Dosing: Seizures - Adults and Children (over age 8 years)
- Titration to maintenance dose (over first 10 days)
- Days 1 to 3: Take 100 to 125 mg orally at bedtime
- Days 4 to 6: Take 100 to 125 mg orally twice daily
- Days 7 to 9: Take 100 to 125 mg orally three times daily
- Days >10: Take 250 mg orally three times daily
- Maintenance dosing
- Standard dosing: 250 mg orally three to four times daily
- Maximum dosing: 500 mg orally four time daily (do not exceed)
VII. Dosing: Seizures - Children (under age 8 years)
- Start 50 mg orally at bedtime
- TItrate dose over 10 days (similar stepped titration schedule as for adults)
- Typical: 125 to 250 mg orally three times daily (10 to 25 mg/kg/day in divided doses)
VIII. Monitoring: Labs every 6 months
- Complete Blood Count
- Chemistry panel (SMA-12)
IX. Adverse effects
X. Safety
- Pregnancy Category D
- Avoid in Lactation
XI. Resources
XII. References
- Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 56-7
- Hamilton (2020) Tarascon Pocket Pharmacopoeia
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