Medications and Drugs
GENERIC NAME: venlafaxine
BRAND NAME: Effexor, Effexor XR
DRUG CLASS AND MECHANISM: Venlafaxine is in a new class
of
anti-depressant medications that affects chemical messengers
within the
brain. These chemical messengers are called neurotransmitters,
and some
examples are serotonin, dopamine, and norepinephrine. Neurotransmitters are manufactured by nerve cells and are released by the cells. The neurotransmitters travel to nearby nerve cells and cause the cells to become more or less active. Many
experts believe
that an imbalance in these neurotransmitters is the cause of
depression and also may
play a role in anxiety. Venlafaxine is believed to work by inhibiting the release or
affecting the action of these neurotransmitters. Venlafaxine is available in
an extended
release formulation (Effexor XR).
PRESCRIPTION: Yes
GENERIC AVAILABLE: Yes
PREPARATIONS: Effexor is available in tablets of 25, 37.5,
50, 75,
and 100 mg. Effexor XR is available in capsules of 37.5, 75, and 150 mg.
STORAGE: Store in a dry place at 20-25°C (68-77°F).
PRESCRIBED FOR: Venlafaxine is
prescribed for the treatment of depression, depression with associated symptoms
of anxiety, generalized anxiety disorder, and social anxiety disorder. Effexor XR is approved for the treatment of adults with panic disorder.
DOSING: Venlafaxine should be taken with food at doses
specifically directed by a physician. Individual doses vary
greatly
among individuals. The anti-depressant effects are not maximal for 1-2 weeks. If discontinued, the dose of venlafaxine should gradually be reduced under the direction of a physician. For patients with difficulty swallowing tablets or capsules, capsules of Effexor XR can be opened and the contents sprinkled on a spoonful of applesauce.
DRUG INTERACTIONS: Life-threatening interactions can occur in
combination with
MAO inhibitors such as Nardil and Parnate. MAO inhibitors and
venlafaxine
should not be taken together, and a waiting period of 14 days
between
taking these two classes of medications is strongly advised.
Most medications affecting the
brain such as venlafaxine have the
potential to slow reflexes or impair judgment. Therefore, caution is
advised especially early in the course of treatment.
Safety has not been established in children below the age of
18 years.
PREGNANCY: The effects of venlafaxine on the fetus are unknown.
NURSING MOTHERS: It is not known if venlafaxine is secreted in milk and, therefore, if it may have an effect on nursing infants.
SIDE EFFECTS: Venlafaxine, like most anti-depressants,
can cause
nausea, headaches, anxiety, insomnia, drowsiness, and loss of
appetite.
Increased blood pressure can occur, and blood pressure should be monitored.
Seizures have
been reported.
"If anti-depressants are discontinued abruptly, symptoms may occur
such as
dizziness, headache, nausea, changes in mood, or changes in the sense
of
smell, taste, etc. (Such symptoms even may occur when even a few
doses of
anti-depressant are missed.) Therefore, it is recommended that the
dose of
anti-depressant be reduced gradually when therapy is discontinued."
Reference: FDA Prescribing Information
Last Editorial Review: 1/10/2006
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
- Drug Interactions - Learn about potential drug interactions you may be exposed to. Drug interactions can occur with prescription drugs, OTC medication, vitamins, herbs, and supplements.
- Anxiety - Read about anxiety (generalized anxiety disorder, GAD) causes, physical symptoms and signs, medications and treatment. Learn about symptoms (worry, fear) and other types of anxiety disorders.
- Antidepressants - Read about the differnent types of antidepressants (used to treat depression) their side effects, drug interactions, and warnings and precautions.
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