Molecule

Drug Groups

approved

Description

Desvenlafaxine, the major active metabolite of venlafaxine, is an antidepressant from the serotonin-norepinephrine reuptake inhibitor (SNRI class). Desvenlafaxine may be used to treat major depressive disorder and is being studied for use in the management of vasomotor symptoms in postmenopausal women.

Indication

Desvenlafaxine is indicated for the treatment of major depressive disorder in adults.

Pharmacology

Desvenlafaxine is a selective serotonin and norepinephrine reuptake inhibitor. It lacks significant activity on muscarinic-cholinergic, H₁-histaminergic, or α₁-adrenergic receptors in vitro. Desvenlafaxine does not appear to exert activity against calcium, chloride, potassium and sodium ion channels and also lacks monoamine oxidase (MAO) inhibitory activity. It was also shown to lack significant activity again the cardiac potassium channel, hERG, in vitro. Compared to other SNRIs, desvenlafaxine undergoes simple metabolism, has a low risk of drug-drug interactions and does not have to be extensively titrated to reach a therapeutic dose. Some of the limitations of desvenlafaxine include moderate efficacy in the treatment of major depressive disorder, similar safety and tolerability profile to other SNRIs and possible transient discontinuation symptoms upon cessation of therapy.

Toxicity

The safety and tolerability of desvenlafaxine is similar to other SNRIs. Common side effects upon initiation or dose increase include increased blood pressure and heart rate, agitation, tremor, sweating, nausea, headache, and sleep disturbances. May cause sexual dysfunction and weight loss in some patients. May cause increases in fasting serum total cholesterol, LDL cholesterol, and triglycerides. Withdrawal effects may occur and thus, the dose of desvenlafaxine should be titrated down prior to discontinuation.

Affected Organisms

Biotransformation

The primary route of metabolism is via conjugation mediated by UGT isoforms. Desvenlafaxine also undergoes oxidative N-demethylation via cytochrome P450 3A4 to a minor extent.

Absorption

Absolute bioavailability is ~ 80% and is unaffected by food.

Half Life

The mean terminal half life is 11.1 hours and may be prolonged in patients with renal and/or moderate to severe hepatic impairment.

Protein Binding

~ 30%, protein binding is independent of drug concentration.

Elimination

Excreted in the urine. Approximately 45% of the total oral dose is excreted unchanged in urine. Approximately 19% of the total oral dose is excreted as the glucuronide metabolite and < 5% is excreted as the oxidative metabolite, N,O-didesmethylvenlafaxine. Excreted in human milk.

Distribution

3.4 L/kg, distribution into nonvascular compartments

References

External Links