Selective serotonin reuptake inhibitor (SSRI)

Citalopram is a widely prescribed SSRI for major depressive disorder and anxiety, marketed as Celexa and Cipramil. It is the racemic mixture from which escitalopram (the more active S-enantiomer) was developed; modern dosing is capped at 40mg daily because of dose-related QT prolongation.

Escitalopram is a selective serotonin reuptake inhibitor (SSRI) widely used for major depression and anxiety disorders. It is the active S-enantiomer of citalopram and is marketed as Lexapro and Cipralex.

Fluoxetine is the first SSRI introduced into clinical practice, marketed as Prozac since 1987 and known for its very long half-life and active metabolite. It is used for depression, OCD, bulimia nervosa and premenstrual dysphoric disorder, and is on the WHO Essential Medicines List.

Paroxetine is one of the older SSRI antidepressants, marketed as Paxil and Seroxat. It has a stronger anticholinergic profile and shorter half-life than other SSRIs, which makes its discontinuation syndrome notably more pronounced and warrants careful tapering.

Sertraline is a selective serotonin reuptake inhibitor (SSRI) used to treat major depressive disorder, panic disorder, OCD, PTSD and social anxiety disorder in adults. Marketed as Zoloft and as authorised generics.