section name header

Pronunciation

ven-la-FAX-een

Classifications

Therapeutic Classification: antidepressants, antianxiety agents

Pharmacologic Classification: selective serotonin and norepinephrine reuptake inhibitors-SSNRIs

Indications

REMS

Unlabeled Uses:

Action

Therapeutic Effects:

Pharmacokinetics

Absorption: 92–100% absorbed after oral administration.

Distribution: Extensive distribution into body tissues.

Metabolism/Excretion: Extensively metabolized on first pass through the liver (primarily through the CYP2D6 isoenzyme); the CYP2D6 isoenzyme exhibits genetic polymorphism (7% of population may be poor metabolizers and may have significantly venlafaxine concentrations and an risk of adverse effects). One metabolite, O-desmethylvenlafaxine (ODV), has antidepressant activity. 5% of venlafaxine is excreted unchanged in urine; 30% of the active metabolite is excreted in urine.

Half-life: Venlafaxine: 3–5 hr; ODV: 9–11 hr (both are in hepatic/renal impairment).

Time/Action Profile

(antidepressant action)

ROUTEONSETPEAKDURATION
POwithin 2 wk2–4 wkunknown

Contraind./Precautions

Contraindicated in:

Use Cautiously in:

Adv. Reactions/Side Effects

CV: chest pain, hypertension, palpitations, tachycardia.

Derm: ecchymoses, itching, photosensitivity, skin rash.

EENT: rhinitis, visual disturbances, epistaxis, tinnitus.

GI: abdominal pain, altered taste, anorexia, constipation, diarrhea, dry mouth, dyspepsia, nausea, vomiting, weight loss.

GU: libido, delayed/absent orgasm, ejaculatory delay/failure, erectile dysfunction, urinary frequency, urinary retention.

Hemat: BLEEDING.

Neuro: abnormal dreams, anxiety, dizziness, headache, insomnia, nervousness, paresthesia, weakness, abnormal thinking, agitation, confusion, depersonalization, drowsiness, emotional lability, NEUROLEPTIC MALIGNANT SYNDROME, SEIZURES, SUICIDAL THOUGHTS, twitching, worsening depression.
Misc: chills, discontinuation syndrome, SEROTONIN SYNDROME, yawning.

Interactions

Drug-Drug:

Drug-Natural Products:

Route/Dosage

Major Depressive Disorder

Renal Impairment

Hepatic Impairment

General Anxiety Disorder

Renal Impairment

Hepatic Impairment

Social Anxiety Disorder

Renal Impairment

Hepatic Impairment

Panic Disorder

Hepatic Impairment

Renal Impairment

Availability

(Generic available)

Assessment

Lab Test Considerations:

Implementation

Patient/Family Teaching

Evaluation/Desired Outcomes

US Brand Names

Effexor, Effexor XR

Pill Image

venlafaxine_195_8941.jpg