Brivaracetam

Brivaracetam (trade name Briviact), a chemical analog of levetiracetam, is a racetam derivative with anticonvulsant (antiepileptic) properties. It is marketed by the pharmaceutical company UCB. In India it is co-promoted and distributed by Dr. Reddy's Laboratories. Brivaracetam (trade name Briviact), a chemical analog of levetiracetam, is a racetam derivative with anticonvulsant (antiepileptic) properties. It is marketed by the pharmaceutical company UCB. In India it is co-promoted and distributed by Dr. Reddy's Laboratories. Brivaracetam is used to treat partial-onset seizures with or without secondary generalisation, in combination with other antiepileptic drugs. No data are available for its effectiveness and safety in patients younger than 16 years. It is sometimes prescribed as an alternative to the drug's analogue levetiracetam to avoid neuropsychiatric adverse effects such as mood swings, anxiety, emotional lability, and depression. The most common adverse effects include sleepiness, dizziness, nausea and vomiting. More rarely, coordination problems and changes in behaviour can occur. Coadministration of brivaracetam with carbamazepine may increase exposure to carbamazepine-epoxide, the active metabolite of carbamazepine, and could theoretically lead to reduced tolerability. Coadministration of brivaracetam with phenytoin may increase phenytoin levels. Coadministration of other antiseizure drugs are unlikely to affect brivaracetam exposure. Brivaracetam provides no added therapeutic benefit when administered in conjunction with levetiracetam that acts on the same protein. Brivaracetam is believed to act by binding to the ubiquitous synaptic vesicle glycoprotein 2A (SV2A), like levetiracetam. but with 20-fold greater affinity. There is some evidence that racetams including levetiracetam and brivaracetam access the luminal side of recycling synaptic vesicles during vesicular endocytosis. They may reduce excitatory neurotransmitter release and enhance synaptic depression during trains of high-frequency activity, such as is believed to occur during epileptic activity. Brivaracetam exhibits linear pharmacokinetics over a wide dose range, is rapidly and completely absorbed after oral administration, has an elimination half-life of 7 to 8 hours, and has plasma protein binding of less than 20%. It is extensively metabolized (>90%), primarily via hydrolysis of the acetamide group, and secondarily through hydroxylation mediated by the liver enzyme CYP2C19. The three major metabolites (hydroxy, acid, and hydroxyacid) are pharmacologically inactive. Brivaracetam is eliminated as urinary metabolites, with over 95% of a radioactive test dose recovered in the urine within 72 hours, including only 8.6% as unchanged brivaracetam. As noted above, brivaracetam is primarily metabolized by hydrolysis, via amidase enzymes, to an inactive metabolite. To a lesser extent, it is also metabolized by a minor metabolic pathway via CYP2C19-dependent hydroxylation. Individuals who have no CYP2C19 enzyme activity, “CYP2C19 poor metabolizers”, will have a greater exposure to standard doses of brivaracetam. Because they are less able to metabolize the drug to its inactive form for excretion, they may have an increased risk of adverse effects. The most common adverse effects of brivaracetam therapy include sedation, fatigue, dizziness, and nausea. The FDA-approved drug label for brivaracetam states that patients who are CYPC19 poor metabolizers, or are taking medicines that inhibit CYP2C19, may require a dose reduction. Brivaracetam is the 4R-propyl analogue of the anticonvulsant levetiracetam.