desvenlafaxine
Pharmacologic class: Selective serotonin reuptake inhibitor
Therapeutic class: Antidepressant
Pregnancy risk category C
FDA Box Warning
• Drug may increase risk of suicidal thinking and behavior in children and adolescents with major depressive disorder and other psychiatric disorders. Risk must be balanced with clinical need, as depression itself increases suicide risk. With patient of any age, observe closely for clinical worsening, suicidality, and unusual behavior changes when therapy begins. Advise family and caregivers to observe patient closely and communicate with prescriber as needed.
• Drug isn't approved for use in children.
Action
Potentiates serotonin and norepinephrine in CNS
Availability
Tablets (extended-release): 50 mg, 100 mg
Indications and dosages
➣ Major depressive disorder
Adults: 50 mg P.O. daily
Dosage adjustment
• Severe renal impairment and end-stage renal disease
• Hepatic impairment (dosages above 100 mg daily not recommended)
Contraindications
• Hypersensitivity to drug, its components, or venlafaxine
• Within 14 days of an MAO inhibitor
Precautions
Use cautiously in:
• renal impairment, hypertension, cardiovascular or cerebrovascular disease, lipid metabolism disorders, abnormal bleeding, interstitial lung disease, eosinophilic pneumonia, seizure disorder, bipolar disorder or family history of mania or hypomania, increased intraocular pressure, increased risk of angle-closure glaucoma
• concurrent use of selective serotonin reuptake inhibitors (SSRIs) or serotonin norepinephrine reuptake inhibitors (SNRIs) (use not recommended)
• pregnant or breastfeeding patients
• children (safety and efficacy not established).
Administration
• Make sure hypertension is controlled before therapy starts.
• Give tablets whole with or without food at same time each day. Don't break, dissolve, or divide tablets.
• Reduce dosage gradually when discontinuing drug.
Adverse reactions
CNS: dizziness, insomnia, somnolence, anxiety, fatigue, irritability, abnormal dreams, hypomania, mania, seizures
CV: hypertension
EENT: mydriasis, blurred vision, tinnitus
GI: nausea, vomiting, diarrhea, constipation, dry mouth
GU: male sexual function disorder
Hematologic: abnormal bleeding
Respiratory: interstitial lung disease, eosinophilic pneumonia
Skin: hyperhidrosis
Other: decreased appetite, weight loss
Interactions
Drug-drug. Aspirin, NSAIDs, other drugs that affect coagulation: increased risk of bleeding
Drugs metabolized by CYP2D6 (such as despiramine): increased blood levels of these drugs
Drugs metabolized by CYP3A4 (such as midazolam): decreased blood levels of these drugs
MAO inhibitors, serotonergics (lithium, SNRIs, SSRIs, tricyclic antidepressants, triptans), tramadol: potentially life-threatening serotonin syndrome
Potent CYP3A4 inhibitors: increased desvenlafaxine blood level
Drug-diagnostic tests. Cholesterol, triglycerides: increased levels
Sodium: decreased level
Urine protein: transient elevation
Drug-food. Triptophan supplements: potentially life-threatening serotonin syndrome
Drug-herb. St. John's wort: potentially life-threatening serotonin syndrome
Patient monitoring
• Monitor patient's blood pressure regularly during therapy.
• Monitor cholesterol and triglyceride levels.
☞ Monitor patient closely for clinical worsening, suicidality, and unusual behavior changes, especially during first few months of therapy and after dosage changes.
☞ Monitor for progressive dyspnea, cough, or chest discomfort, which may signal serious lung disorders.
• Observe for signs and symptoms of hyponatremia (headache, poor concentration, memory impairment, confusion, weakness, and unsteadiness), especially in elderly patients.
☞ After discontinuing drug, monitor for dysphoric mood, irritability, agitation, dizziness, paresthesia, anxiety, confusion, headache, lethargy insomnia, tinnitus, and seizures.
Patient teaching
• Instruct patient to take tablets whole with or without food at same time each day. Caution patient not to chew, break, crush, dissolve, or divide tablets.
• Tell patient that full drug effects may take several weeks; advise patient not to stop taking drug.
• Caution patient not to discontinue drug abruptly.
☞ Advise patient's family or caregiver to monitor patient, especially for suicidality or new or worsening symptoms.
☞ Instruct patient to immediately report unusual bruising or bleeding.
• Advise patient not to take over-the-counter drugs containing aspirin or NSAIDs without consulting prescriber.
• Instruct patient to avoid herbs (especially St. John's wort) unless prescriber approves.
• Caution patient to avoid hazardous activities until drug's effects on concentration and alertness are known.
• Tell patient that inert matrix tablet may appear in stool, but active drug has already been absorbed.
• Advise female patient to notify prescriber if she is pregnant, intends to become pregnant, or is breastfeeding.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, foods, and herbs mentioned above.