Antidepressants increase risk of suicidal thinking and behavior in children, adolescents, and young adults (18-24 years of age) with major depressive disorder and other psychiatric disorders. Venlafaxine not FDA approved for use in children. Possibility of suicide attempt inherent in major depression and may persist until remission occurs. May worsen psychosis in some patients or precipitate shift to mania or hypomania in bipolar disorder. Monotherapy in bipolar disorder should be avoided. Venlafaxine not FDA approved for treatment of bipolar depression. May cause increase in anxiety, nervousness, and insomnia. May impair platelet aggregation resulting in increased risk of bleeding events, particularly if used concomitantly with aspirin or NSAIDs due to ulcerogenic potential. Has low potential to cause CNS depression. May cause hypercholesterolemia. Dose-related increases in systolic and diastolic blood pressure documented. Interstitial lung disease and eosinophilic pneumonia rarely reported (may present as progressive dyspnea, cough, and/or chest pain). May cause or exacerbate sexual dysfunction. SSRIs and SNRIs associated with development of SIADH. Hyponatremia reported rarely (including severe cases with serum sodium <110 mmol/L), predominately in the elderly. Dose-dependent weight loss observed in both pediatric and adult patients. May cause sustained increase in blood pressure or tachycardia (use caution in recent history of myocardial infarction, unstable heart disease, or hyperthyroidism). Use caution in hepatic and renal impairment (clearance decreased and plasma concentrations increased). May cause mydriasis (use caution in increased intraocular pressure or risk of acute narrow-angle glaucoma). Use caution with previous seizure disorder or condition predisposing to seizures such as brain damage or alcoholism. Use caution with concomitant use of NSAIDs, ASA, or other drugs which affect coagulation (risk of bleeding may be potentiated). Concurrent use with MAOIs contraindicated (potential for serotonin syndrome). Do not begin venlafaxine within 14 days of terminating MAOI therapy. Do not initiate MAOI treatment within 7 days of discontinuing venlafaxine. Serotonin syndrome (e.g. symptoms of agitation, confusion, hallucinations, hyper-reflexia, myoclonus, shivering, and tachycardia) may occur with concomitant proserotonergic drugs (i.e. SSRIs/SNRIs or triptans) or agents which reduce metabolism of venlafaxine. Concurrent use of serotonin precursors (e.g. tryptophan) not recommended. Agents causing weight loss or anorectic effects should be avoided. Not FDA approved for use in children. May increase risks associated with electroconvulsive therapy. Withdrawal syndrome might occur upon abrupt discontinuation or dosage reduction.