Venlafaxine (Effexor) for Depression Therapy

  • Type of Drug: Antidepressant.
  • Prescribed for: Depression.
  • Brand Name: Effexor.

General Information Venlafaxine (Effexor)

Venlafaxine is chemically different from other antidepressants. It is believed to work by affecting the ability of nerve endings in the brain to absorb serotonin, norepinephrine, and dopamine; it does not affect monoamine oxidase (MAO). Venlafaxine is well absorbed into the bloodstream and passes out of the body primarily via the urine.

Cautions and Warnings

People with severe liver or kidney disease may require smaller than usual doses of Venlafaxine because these conditions cart cause blood levels of the drug to increase by 30 to 50 percent.
Venlafaxine raises blood pressure. If this happens, your dosage of Venlafaxine may have to be reduced. Venlafaxine has not been studied in people with a recent heart attack or unstable heart disease, though a small study of the cardiograms of such patients revealed no unusual changes.

Possible Side Effects of Venlafaxine (Effexor)

Many drug side effects increase as you increase the dosage of Venlafaxine.

  • Most common: sleepiness, dry mouth, dizziness, sleeplessness, nervousness, tremors, weakness, sweating, nausea, constipation, loss of appetite, anorexia, vomiting, and impotence or abnormal ejaculation.
  • Less common: changes in taste perception, ringing in the ears, dilated pupils, blurred vision, high blood pressure, rapid heartbeat, anxiety, reduced sex drive, agitation, chills, yawning, orgasm disturbance, dizziness when rising from a sitting or lying position, unusual dreams, muscle stiffness, tingling in the hands or feet, confusion, abnormal thinking, depression, urinary difficulties, twitching, chest pain, trauma, weight loss, itching, rash, diarrhea, upset stomach, gas, menstrual disturbances, and urinary difficulty.
  • Rare: swelling, weight gain, a hangover-type reaction, hernia, unusual sensitivity to the sun, suicide attempts, appendicitis, thyroid changes, migraines, angina pains, heart rhythm changes, increased pulse rate, swallowing difficulty, stomach irritation, irritated or bleeding gums, salivation, soft stools, tongue discoloration, ulcers, reduced blood-cell counts, abnormal vision, ear pain, acne, hair loss, brittle nails, dry skin, herpes, and hairiness.

Drug Interactions

  • People who take Venlafaxine within 2 weeks after taking an MAO inhibitor antidepressant may experience severe reactions, including high fever, muscle rigidity or spasm, mental changes, and fluctuations in pulse, temperature, or breathing rate. People stopping an MAO inhibitor should wait at least 2 weeks before starting Venlafaxine. People stopping Venlafaxine should wait at least 1 week before starting an MAO inhibitor drug.
  • Cimetidine reduces the rate at which Venlafaxine is broken down in the body, and thus may increase drug levels in the blood, although the effect on your body may be minimal.

Venlafaxine (Effexor) Food Interactions

Take each dose of Venlafaxine with food.

Usual Dose

Adult: 75 to 350 mg per day, divided into 2 or 3 doses. People with severe kidney or liver disease should receive half the usual daily dose. Those with moderate kidney disease may have their daily dose reduced by only 25 percent.

Child: not recommended for children under age 18.

Overdosage

Most people taking overdoses of Venlafaxine reported no symptoms, although some experienced fatigue. One person experienced mild convulsions and cardiac effects – contact your doctor or emergency room if you experience similar effects. People who take an overdose of Venlafaxine should be taken to a hospital emergency room for treatment. ALWAYS bring the medicine bottle with you.

Special Information

Call your doctor if you develop rash, hives, or any other allergic reaction.

Venlafaxine can make you tired. Avoid alcoholic beverages while taking Venlafaxine, and take care while performing complicated functions, driving, or operating complex equipment.

Contact your doctor or pharmacist if you are taking any other medicines, because of possible adverse drug interactions. If you forget to take a dose of Venlafaxine, take it as soon as you remember. If it is almost time for your next dose, skip the forgotten dose and continue with your regular schedule.

Do not suddenly discontinue this medicine. It Is recommended that the dosage of Venlafaxine be gradually reduced over a 2-week period.

Venlafaxine (Effexor) Special Populations

Pregnancy/Breast-feeding
Animal studies of Venlafaxine in doses 10 times larger than the maximum human dose caused low birth weight and deaths. No information is available on the effect of Venlafaxine on human pregnancy; it should be taken during pregnancy only if it is clearly needed.
It is not known if Venlafaxine or its breakdown products pass into breast milk; therefore, risks to the infant should be carefully weighed against the benefits to the mother. Nursing mothers should consider bottle-feeding with formula.

Seniors
Some older adults may be more sensitive to Venlafaxine’s side effects.