A mental disorder, also referred to as a mental illness or psychiatric disorder, is a behavioral or mental pattern that causes significant distress or impairment of personal functioning. Such features may be persistent, relapsing and remitting, or occur as single episodes. Many disorders have been described, with signs and symptoms that vary widely between specific disorders. Such disorders may be diagnosed by a mental health professional, usually a clinical psychologist or psychiatrist. The causes of mental disorders are often unclear. Theories may incorporate findings from a range of fields. Mental disorders are usually defined by a combination of how a person behaves, feels, perceives, or thinks. This may be associated with particular regions or functions of the brain, often in a social context. A mental disorder is one aspect of mental health. Cultural and religious beliefs, as well as social norms, should be taken into account when making a diagnosis.Services are based in psychiatric hospitals or in the community, and assessments are carried out by mental health professionals such as psychiatrists, psychologists, psychiatric nurses and clinical social workers, using various methods such as psychometric tests but often relying on observation and questioning. Treatments are provided by various mental health professionals. Psychotherapy and psychiatric medication are two major treatment options. Other treatments include lifestyle changes, social interventions, peer support, and self-help. In a minority of cases, there might be involuntary detention or treatment.
Pharmacokinetics
Brivaracetam exhibits linear pharmacokinetics over a wide dose range, is rapidly and completely absorbed after oral administration, has an elimination half-life of seven to eight 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. Pharmacogenetics
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. Chemical and physical properties
Brivaracetam is the 4R-propyl analogue of the anticonvulsant levetiracetam.