Phenobarbital is a long-acting barbiturate sedative, hypnotic and anticonvulsant working by depressing the central nervous system, hence used for sedation, and treatment and prevention of seizures and epilepsy.
Phenobarbital is available in Hong Kong as injections, syrups and tablets. It can be taken with or without food. If it is to be injected into muscles, inject deep into muscle at a volume of less than 5 mL per injection site to minimize tissue irritation.
Oral, intravenous, intramuscular: 30-120 mg daily in 2 to 3 divided doses increased up to 400 mg daily.
Intramuscular: 100-200 mg 60-90 minutes before operations
Maintenance of seizures
Oral, intravenous: 2 mg/kg daily in divided doses
Oral: 3-6 mg/kg daily in divided doses
Intravenous: 15-20 mg/kg daily in divided doses
Intravenous: 15-20 mg/kg daily in divided doses up to 1000 mg per dose
For those being administered with IV infusion:
Common dosing schedule:
Oral Phenobarbital is to be taken at divided doses, usually 2-3 times. Take it with meals for convenience.
For the injections, they are to be injected when you are hospitalized.
This schedule is for reference only, adjustments may be made according to individual needs.
Some common medications Phenobarbital may interact with:
Phenobarbital may interact with many other medications. Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.
In Hong Kong, Phenobarbital is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.
For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at https://www.drugoffice.gov.hk
Need more information?
For detailed information about the use of Phenobarbital in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.
Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.