||Chemical Name |
(U.S. and Canada)
Primary Usage in MS
Venlafaxine is used to treat mental depression and certain types of anxiety.
Unless your physician has instructed otherwise, this medication should be taken with food or on a full stomach to reduce the chances of stomach upset.
If you miss a dose of this medication, take it as soon as possible. If, however, it is within two hours of your next dose, skip the missed dose and return to your regular schedule. Do not double dose.
It may take 4-6 weeks for you to feel the beneficial effects of this medication.
Your physician should monitor your progress at regularly scheduled visits in order to adjust the dose and help reduce any side effects.
Do not stop taking this medication without consulting your physician. The doctor may want you to reduce the amount you are taking gradually in order to decrease unwanted side effects.
This medication could add to the effects of alcohol and other central nervous system depressants (e.g., antihistamines, sedatives, tranquilizers, sleeping medicine, prescription pain medicine, barbiturates, seizure medication, muscle relaxants). Be sure that you doctor knows if you are taking these or any other medications. Venlafaxine may cause dryness of the mouth. If your mouth continues to feel dry for more than two weeks, check with your physician or dentist. Continuing dryness of the mouth may increase the risk of dental disease.
This medication may cause you to become drowsy or to have double vision.
Venlafaxine may cause dizziness, lightheadedness, or fainting, especially when you stand from a sitting or lying position. If rising slowly from a sitting or lying position does not relieve the problem, consult your physician.
Studies have not been done in pregnant women. However, studies in animals have shown that venlafaxine may cause decreased survival rates of offspring when given in doses that are many times the usual dose for humans. If you are pregnant, or planning to become pregnant, do not start this medication before you have discussed it with your physician.
It is not known whether venlafaxine passes into breast milk. Mothers who are taking this medication and wish to breastfeed should discuss this with their doctor.
Possible Side Effects
Side effects that will typically go away as your body adjusts to the medication and do not require medical attention unless they continue for several weeks or are bothersome: abnormal dreams; anxiety or nervousness; constipation*, dizziness, drowsiness*, dryness of mouth, tingling or burning sensations*, decreased appetite, nausea, stomach or abdominal cramps; trouble sleeping; tiredness*; tremor*.
Unusual side effects which should be discussed with the doctor as soon as possible: changes in vision or double vision*; changes in sexual desire or ability*; headache, chest pain; fast heartbeat; itching or skin rash; mood or mental changes; problems with urination*; menstrual changes; uncontrolled excitability; high blood pressure.
Symptoms of overdose include: extreme drowsiness, tiredness, or weakness*.
* Since it may be difficult to distinguish between certain common symptoms of MS and some side effects of venlafaxine, be sure to consult your health care professional if an abrupt change of this type occurs.