New Drug For Major Depression

Adults experiencing major depression now have a new Food and Drug Administration-approved treatment option. Desvenlafaxine (Pristiq) is a serotonin-norepinephrine reuptake inhibitor (SNRI) approved for the treatment of major depressive disorder in adults.

Available in 50 mg and 100 mg tablets, desvenlafaxine is typically prescribed as a 50 mg dose taken once daily either with or without food. Patients with renal impairment are typically dosed at 50 mg every other day. Those with hepatic impairment may be dosed up to 100 mg daily (but not greater).

Adverse reactions: Common adverse reactions include nausea, insomnia, dizziness, hyperhidrosis, constipation, somnolence, decreased appetite, anxiety, and male sexual dysfunction. Other less-common but more serious adverse reactions include hypertension, abnormal bleeding, narrow-angle glaucoma, and seizures.

Contraindications: Patients must not use desvenlafaxine in combination with a monoamine oxidase inhibitor. There must also be a “washout period” of 14 days after an MAOI has been stopped and the introduction of desvenlafaxine therapy. Likewise, if desvenlafaxine therapy is discontinued, a MAOI must not be started for seven days to avoid serious and sometimes fatal drug interactions. Symptoms of drug interactions include myoclonus, hyperthermia with features resembling neuroleptic malignant syndrome, seizures, autonomic instability with possible rapid fluctuations of vital signs, and progression to delirium and coma.

Patient monitoring: Abnormal lab values have been reported, including hyponatremia and elevated cholesterol and triglyceride levels. Encourage patients to follow their prescribing professionals’ recommendations regarding scheduled laboratory testing.

The drug carries a black box warning for increased risk of suicidal thinking and behavior in children, adolescents, and young adults taking antidepressants for major depressive disorder and other psychiatric disorders. While desvenlafaxine is not approved for use in pediatric patients, it may be prescribed “off label” and warrant special concern and observation.

Activation of mania and hypomania has also occurred, warranting special caution and observation when used for patients with bipolar disorder.

Patient teaching: Remind patients that the tablets must be swallowed whole with fluid and not divided, crushed, chewed, or dissolved. To avoid discontinuation symptoms, recommend gradually tapering off the medication.

Caution: Review current drug information before administering and monitoring medications.