Pharmacological management of bipolar affective disorder

Abstract

Many drug treatments are used in bipolar disorder. Lithium is the gold standard. It has efficacy in the treatment of mania, prophylaxis against manic relapses, and to a lesser extent prophylaxis against depressive relapses. It has been shown to decrease suicidal risk. Therapeutic blood monitoring of lithium is necessary. In addition to side effects, problems include rebound mania on abrupt secession of lithium, and teratogenetic risks. Carbamazepine, valproate and lamotrigine are anticonvulsants with an evidence base in bipolar disorder. Carbamazepine is anti-manic but poorly tolerated and associated with many pharmacokinetic interactions. Valproate is also anti-manic and has some data suggesting it is anti-depressant in bipolar disorder and is prophylactic, especially against mania. It is associated with many problems if used during pregnancy and this should be avoided if possible. Lamotrigine is not licensed for use in the treatment of bipolar disorder in the UK but has some evidence for effectiveness against bipolar depression or more particularly prophylaxis against depressive relapse. It must be introduced slowly to avoid dangerous skin reactions. Other anticonvulsants have no evidence supporting their use. Antipsychotics, including the atypicals, are effective in treating mania. Olanzapine is also licensed for long-term prophylaxis and quetiapine has evidence for effectiveness in treating bipolar depression. Antidepressants, especially tricylcics and MAOIs, should be avoided due to risks of switching to mania. In general if an antidepressant is used it should ideally be an SSRI and using in conjuncture with a mood stabiliser and for the shortest period necessary.