Desvenlafaxine Succinate is prescribed for the treatment of Major Depressive Disorder (MDD). It is generally recognized that acute episodes of MDD require ongoing pharmacological treatment for several months or more. Patients should be regularly evaluated to decide whether continued therapy is necessary.

Desvenlafaxine is a synthetic version of the primary active metabolite of venlafaxine and belongs to the class of Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs). It functions by inhibiting the reuptake transport proteins of key neurotransmitters involved in mood regulation, which increases their availability in the synaptic space. The affected neurotransmitters include serotonin (5-hydroxytryptamine) and norepinephrine (noradrenaline). It is about 10 times more effective at inhibiting serotonin reuptake than norepinephrine reuptake.

The exact antidepressant mechanism of desvenlafaxine is not fully understood, but it is believed to be related to the enhancement of serotonin and norepinephrine activity in the central nervous system by preventing their reabsorption. Non-clinical studies indicate that desvenlafaxine is a strong serotonin and norepinephrine reuptake inhibitor (SNRI).

The recommended dose for Desvenlafaxine Succinate is 50 mg once daily, with or without food. In clinical studies, doses of 50-400 mg/day were shown to be effective. When discontinuing therapy, gradual dose reduction is recommended whenever possible to minimize discontinuation symptoms. Desvenlafaxine Succinate should be taken at approximately the same time each day. Tablets must be swallowed whole with fluid and not divided, crushed, chewed, or dissolved.

Clinical studies indicate that desvenlafaxine at a dose of 100 mg daily does not have a clinically significant impact on CYP2D6 metabolism of drugs such as desipramine, atomoxetine, dextromethorphan, metoprolol, nebivolol, perphenazine, and tolterodine. However, when 400 mg of desvenlafaxine is co-administered, the dose of these substrates should be reduced by half. Desvenlafaxine should not be used together with other products containing desvenlafaxine or with venlafaxine, as this may increase blood levels of desvenlafaxine and raise the risk of dose-related side effects. As with other central nervous system (CNS) acting medications, patients are advised to avoid alcohol consumption while taking desvenlafaxine.

Desvenlafaxine Succinate is contraindicated in patients with known hypersensitivity to desvenlafaxine succinate, venlafaxine hydrochloride, or any of the excipients in the formulation. The use of monoamine oxidase inhibitors (MAOIs) intended for the treatment of psychiatric disorders with desvenlafaxine, or within 7 days of stopping desvenlafaxine therapy, is contraindicated. Similarly, desvenlafaxine should not be started within 14 days of discontinuing an MAOI used for psychiatric treatment.

Common side effects may include nausea, dizziness, insomnia, excessive sweating (hyperhidrosis), constipation, drowsiness (somnolence), reduced appetite, anxiety, dry mouth, and specific sexual dysfunctions in males.

Pregnancy Category C. Desvenlafaxine should be used during pregnancy only when the expected benefits outweigh the potential risks to the fetus. Desvenlafaxine (O-desmethylvenlafaxine) is known to pass into human breast milk. Due to the possibility of serious adverse effects in nursing infants, a decision should be made either to stop breastfeeding or to discontinue the drug, considering the importance of treatment for the mother.

Patients with Major Depressive Disorder (MDD), including both adults and children, may experience worsening depression, the emergence of suicidal thoughts or behaviors, or other unusual behavioral changes, whether or not they are receiving antidepressant treatment. This risk may continue until significant improvement occurs. A combined analysis of short-term placebo-controlled studies of antidepressants (including SSRIs and others) found an increased risk of suicidal thoughts and behaviors in children, adolescents, and young adults (aged 18 to 24) with MDD and other psychiatric conditions. However, in adults older than 24, these short-term studies did not show an increased risk of suicidality compared with placebo.

Dosage Adjustment in Renal Impairment: No dose adjustment is required for patients with mild renal impairment. In patients with moderate renal impairment, the recommended dose is 50 mg once daily. For patients with severe renal impairment or end-stage renal disease (ESRD), the maximum recommended dose is 50 mg every other day. No additional dose should be given after dialysis. Dose escalation is not recommended in patients with moderate or severe renal impairment or ESRD.

Dosage Adjustment in Hepatic Impairment: In patients with hepatic impairment, the recommended dose is 50 mg once daily. A dose higher than 100 mg per day is not recommended.

Serotonin-norepinephrine reuptake inhibitor (SNRI)

Store at a temperature below 30°C. Protect from light and moisture. Keep out of reach of children.