Effexor XR (venlafaxine) is a prescription capsule that’s used to treat depression, anxiety, and panic disorder. Learn about side effects, dosage, and more. EFFEXOR XR prescription and dosage information for physicians and health care professionals. Pharmacology, adverse reactions, warnings, and EFFEXOR XRside effects. Taking EFFEXOR XR can cause a potentially life-threatening problem called serotonin syndrome. The risk of developing serotonin syndrome is increased when EFFEXOR XR is taken with certain other medicines. Find medical information for Effexor XR on epocrates online, including its dosing, contraindications, drug interactions, and pill pictures. Review the most frequently asked questions for EFFEXOR XR® (venlafaxine HCl) and talk to your doctor. Please see the Med Guide & Full Prescribing Info, including Boxed WARNING. Extended-release venlafaxine dosage increases can be made at intervals of 2 weeks or more, but not less than 4 days. Patients treated with venlafaxine immediate-release tablets may be switched to venlafaxine extended-release capsules at the nearest equivalent daily dosage. Effexor XR (venlafaxine) is used to treat major depressive disorder, anxiety, and panic disorder. Includes Effexor XR side effects, interactions and indications. Find patient medical information for Venlafaxine (Effexor) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings Effexor XR: side effects, dosage, interactions, FAQs, reviews. Used for: anxiety, autism, depression, generalized anxiety disorder, major depressive disorder, panic disorder, and more. Effexor XR (Venlafaxine Hydrochloride Extended-Release) may treat, side effects, dosage, drug interactions, warnings, patient labeling, reviews, and related medications including drug comparison and health resources.