Effexor (Venlafaxine) is a prescription medication that belongs to a class of medications called the serotonin-norepiniphrine reuptake inhibitors (SNRIs). It is indicated for the treatment of major depressive disorder, generalized anxiety disorder (GAD), social anxiety disorder and panic disorder. It alleviates symptoms by correcting the imbalance of two chemicals in the brain, serotonin and norepiniphrine. Because this drug is actively working in the body, it is normal to experience side effects during the course of administration.
Common Side Effects
Like all medications, Effexor can give rise to many common side effects. These side effects usually occur when treatment is initiated and will slowly decrease as the body adjusts to the medication. Headaches and nausea are two major side effects, occurring in about 30 percent of people. Dizziness, dry mouth, and difficulty sleeping are also common and occur in about 15 percent of people. About 14 percent of the individuals taking Effexor may experience loss of appetite; this may account for the weight changes seen in some. Other common side effects of this medication include constipation, nervousness, abnormal dreams, sweating and muscle weakness. Collaborating with a health care provider may help in managing potential side effects and solve any issues.
Sexual Side Effects
Effexor may decrease libido, or sexual desire, and has been associated with delayed ejaculation or abnormal orgasm in about 10 percent of people. Impotence and lack of an orgasm are less common but have occurred about 5 percent of people. It is important to discuss any major concerns about sexual dysfunction with a health care provider.
Hypertension
Effexor may cause hypertension, which is an increase in the blood pressure. Therefore, it is extremely important that individuals inform their physician if they have or ever have had high blood pressure. According to the Drug Information Handbook, this effect is directly related to the dose given. Only about 3 percent of people may experience a rise in blood pressure if the dose is less than 100mg per day. However, when the dose is more than 300mg per day, occurrence increases to 13 percent. Fast or uneven heartbeat or chest pain may be signs of an elevated blood pressure. This requires the discontinuation of the drug and medical attention.
References
- Drugs.com: Effexor Side Effects
- Effexor XR: Managing Potential Side Effects
- "Drug Information Handbook 15th Edition"; Charles F. Lacy, RPh, PharmD, FCSHP, Lora L. Armstrong, RPh,PharmD, BCPS, et al; 2007
