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Effexor XR - Warnings & Precautions

[venlafaxine hydrochloride]

WARNINGS

Potential for Interaction with Monoamine Oxidase Inhibitors

Adverse reactions, some of which were serious, have been reported in patients who have recently been discontinued from a monoamine oxidase inhibitor (MAOI) and started on venlafaxine, or who have recently had venlafaxine therapy discontinued prior to initiation of an MAOI. These reactions have included

tremor,

myoclonus,

diaphoresis,

nausea,

vomiting,

flushing,

dizziness,

hyperthermia with features resembling neuroleptic malignant syndrome, seizures,

death.

In patients receiving antidepressants with pharmacological properties similar to venlafaxine in combination with an MAOI, there have also been reports of serious, sometimes fatal, reactions.

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For a selective serotonin reuptake inhibitor, these reactions have included hyperthermia,

rigidity,

myoclonus,

autonomic instability with possible rapid fluctuations of vital signs,

mental status changes that include extreme agitation progressing to delirium and coma.

Some cases presented with features resembling neuroleptic malignant syndrome. Severe hyperthermia and seizures, sometimes fatal, have been reported in association with the combined use of tricyclic antidepressants and MAOIs. These reactions have also been reported in patients who have recently discontinued these drugs and have been started on an MAOI. The effects of combined use of venlafaxine and MAOIs have not been evaluated in humans or animals.

Therefore, because venlafaxine is an inhibitor of both norepinephrine and serotonin reuptake, it is recommended that Effexor XR (venlafaxine hydrochloride) extended-release capsules not be used in combination with an MAOI, or within at least 14 days of discontinuing treatment with an MAOI. Based on the half-life of venlafaxine, at least 7 days should be allowed after stopping venlafaxine before starting an MAOI.

Sustained Hypertension

Venlafaxine treatment is associated with sustained increases in blood pressure in some patients. Among patients treated with 75 to 375 mg/ day of Effexor XR in premarketing studies in patients with major depressive disorder, 3 (19/ 705) experienced sustained hypertension [defined as treatment-emergent supine diastolic blood pressure (SDBP) 90 mm Hg and 10 mm Hg above baseline for 3 consecutive on-therapy visits]. Among patients treated with 37.5 to 225 mg/ day of Effexor XR in premarketing GAD studies, 0.5 (5/ 1011) experienced sustained hypertension. Among patients treated with 75 to 225 mg/ day of Effexor XR in premarketing Social Anxiety Disorder studies, 1.4% (4/ 277) experienced sustained hypertension.