Sertraline

Originator

Lustral,Pfizer,UK

Uses

Antidepressant;5-HT uptake inhibitor

Uses

cis-Sertraline is an isomer of Sertraline. Sertraline is a selective serotonin reuptake inhibitor. It is used as an antidepressant.

Definition

ChEBI: A member of the class of tetralins that is tetralin which is substituted at positions 1 and 4 by a methylamino and a 3,4-dichlorophenyl group, respectively (the S,S diastereoisomer). A selective serotonin-reuptake inhibito (SSRI), it is administered orally as the hydrochloride salt as an antidepressant for the treatment of depression, obsessive-compulsive disorder, panic disorder and post-traumatic stress disorder.

brand name

Zoloft (Pfizer).

Therapeutic Function

Antidepressant

Biological Functions

Sertraline (Zoloft) has an elimination half-life of 25 hours and can be administered once a day, usually in the morning to avoid insomnia. Sertraline undergoes extensive hepatic metabolism, and doses must be reduced in patients with liver disease. Sertraline may produce more gastrointestinal side effects, such as nausea and diarrhea, than does fluoxetine and is generally thought to be less activating than fluoxetine. It is highly bound to serum proteins (98%) and may alter plasma protein binding of other medications.A 14-day washout period is recommended before starting a MAOI. Sertraline is a weak inhibitor of cytochrome P450 2D6. Intensive therapeutic drug monitoring is indicated when combining sertraline with drugs metabolized by this route that have a narrow therapeutic index, such as the TCAs and the type 1C antiarrhythmics propafenone, encainide, and flecainide.

General Description

Inspection of sertraline (Zoloft) (1S,4S) reveals the pharmacophorefor SERT inhibition. The Cl substituents alsopredict tropism for a 5-HT system. The depicted stereochemistryis important for activity.

Mechanism of action

Sertraline is a potent and selective inhibitor of the neuronal reuptake 5-HT transporter. In vitro binding studies suggest that sertraline has a substantially higher selectivity for inhibiting 5-HT reuptake than other SSRIs or TCAs, including clomipramine. It has only weak effects on neuronal uptake of NE and dopamine. Its mechanism of action is common to the SSRIs. Sertraline is very selective, lacking affinity for other neuroreceptors at therapeutic concentrations.

Pharmacokinetics

Sertraline appears to be slowly but well absorbed from the GI tract following oral administration. The oral bioavailability of sertraline in humans ranges from 20 to 36%, suggesting extensive first-pass metabolism to its N-desmethylated metabolite. Food enhances its oral absorption decreasing the time to achieve peak plasma concentrations from approximately 8 to 6 hours. Following multiple dosing, steady-state plasma sertraline concentrations are proportional and linearly related to dose (half-life: single dose, 24 hours; multiple dose, 24 hours). N-desmethylsertraline, sertraline's principal metabolite, exhibits dose-dependent pharmacokinetics. Sertraline and N-desmethylsertraline are distributed into breast milk. Although in elderly patients the elimination half-life is increased to approximately 36 hours, this effect does not appear to be clinically important and does not warrant dosing alterations. Sertraline is primarily metabolized by CYP3A4 N-demethylation in the intestine and liver to its principal metabolite N-desmethylsertraline and several other metabolites. N-desmethylsertraline is approximately 5- to 10 times less potent as an inhibitor of 5-HT reuptake than sertraline. Sertraline and N-desmethylsertraline undergo further metabolism via oxidative deamination and ring hydroxylation and glucuronide conjugation. N-desmethylsertraline has an elimination half-life approximately 2.5 times that of sertraline. Following oral administration, sertraline and its conjugated metabolites are excreted in both urine and feces, and unmetabolized sertraline accounts for less than 5% of oral dose. Plasma clearance of sertraline was approximately 40% lower in geriatric patients. The elimination half-life of sertraline in patients with hepatic disease was prolonged to a mean of 52 hours, compared with 22 hours in individuals without hepatic disease.

Clinical Use

SSRI:
Antidepressant
Post-traumatic stress disorder
Obsessive compulsive disorder

Drug interactions

Sertraline is not a potent inhibitor of CYP3A4, and because CYP2D6 metabolism is a minor pathway for sertraline, drug–drug interactions with these isoforms is unlikely to be of clinical importance. Sertraline is metabolized by more than one CYP isoform in parallel; therefore, drug interactions or genetic polymorphisms are unlikely to cause clinically significant drug interaction via CYP isoform inhibition. Caution is advised, however, when coadministering sertraline with potential object drugs, especially those with narrow therapeutic indices in elderly patients. For example, sertraline has been shown to reduce the clearance of desipramine and imipramine as a result of CYP2D6 inhibition.
Because sertraline is highly protein bound, patients receiving it concurrently with any highly protein-bound drug should be observed for potential adverse effects associated with combined therapy.

Metabolism

Sertraline undergoes extensive first-pass metabolism in the liver. The main pathway is demethylation to inactive N-desmethylsertraline, a process that appears to involve multiple cytochrome P450 isoenzymes; further metabolism and glucuronide conjugation occurs. Sertraline is excreted in about equal amounts in the urine and faeces, mainly as metabolites.