Information about Phenobarbital
Phenobarbital is a barbiturate that is widely used as a sedative and an antiseizure medication.
Liver safety of Phenobarbital
Phenobarbital has been linked to rare instances of idiosyncratic liver injury that can be severe and even fatal.
Mechanism of action of Phenobarbital
Phenobarbital (fee" noe bar' bi tal) is a barbiturate and is believed to act as a nonselective depressant. Phenobarbital also has anticonvulsant activity and is believed to act by suppressing spread of seizure activity by enhancing the effect of gamma aminobutyric acid (GABA), raising the seizure threshold.
FDA approval information for Phenobarbital
Phenobarbital was introduced into clinical medicine in 1911 but was never subjected to critical controlled studies to demonstrate safety and efficacy. For these reasons, phenobarbital is now considered of unproven benefit in controlling seizures. Neverthess, it is commonly used for prevention and management of partial and generalized seizures, usually as an adjunctive agent in combination with other anticonvulsants. Phenobarbital is also used for sedation and insomnia although its use for these conditions is now uncommon. Phenobarbital is also used in fixed combinations with other antispasmotics or anticholinergic agents and used for gastrointestinal complaints, including irritable bowel syndrome.
Dosage and administration for Phenobarbital
The typical starting dose in treating seizures in adults is 60 to 100 mg in three divided doses daily. Oral formulations of tablets or capsules of 15, 16, 30, 60, 90 and 100 mg are available in multiple generic forms. Parenteral formations and oral elixirs for pediatric use are also available.
Side effects of Phenobarbital
Frequent side effects include drowsiness, sedation, hypotension, and skin rash.