A non-proteinogenic amino acid derivative that is butanamide in which the pro-S hydrogen at position 2 is replaced by a (4R)-2-oxo-4-propylpyrrolidin-1-yl. Used for treatment of partial onset seizures related to epilepsy. ChEBI: Brivaracetam is a non-proteinogenic amino acid derivative that is butanamide in which the pro-S hydrogen at position 2 is replaced by a (4R)-2-oxo-4-propylpyrrolidin-1-yl. Used for treatment of partial onset seizures related to epilepsy. It has a role as an anticonvulsant. It is a gamma-lactam and a non-proteinogenic amino acid derivative. It is functionally related to a L-alpha-aminobutyric acid.