venlafaxine

Effexor

Effexor XR

Indications

Action

Pharmacokinetics

Time/action profile (antidepressant action)

Contraindications/Precautions

Adverse Reactions/Side Effects

Central nervous system

• neuroleptic malignant syndrome (life-threatening)
• seizures (life-threatening)
• suicidal thoughts (life-threatening)
• abnormal dreams (most frequent)
• anxiety (most frequent)
• dizziness (most frequent)
• headache (most frequent)
• insomnia (most frequent)
• nervousness (most frequent)
• weakness (most frequent)
• abnormal thinking
• agitation
• confusion
• depersonalization
• drowsiness
• emotional lability
• worsening depression

Ear, Eye, Nose, Throat

• rhinitis (most frequent)
• visual disturbances (most frequent)
• epistaxis
• tinnitus

Cardiovascular

• chest pain
• hypertension
• palpitations
• tachycardia

Gastrointestinal

• abdominal pain (most frequent)
• altered taste (most frequent)
• anorexia (most frequent)
• constipation (most frequent)
• diarrhea (most frequent)
• dry mouth (most frequent)
• dyspepsia (most frequent)
• nausea (most frequent)
• vomiting (most frequent)
• weight loss (most frequent)

Genitourinary

• sexual dysfunction (most frequent)
• urinary frequency
• urinary retention

Dermatologic

• ecchymoses (most frequent)
• itching
• photosensitivity
• skin rash

Neurologic

• paresthesia (most frequent)
• twitching

Miscellaneous

• serotonin syndrome (life-threatening)
• chills (most frequent)
• bleeding
• yawning

Interactions

Drug-Drug interaction

Route/Dosage

Availability (generic available)

Nursing implications

Nursing assessment

• Assess mental status and mood changes. Inform health care professional if patient demonstrates significant increase in anxiety, nervousness, or insomnia.
• Assess suicidal tendencies, especially in early therapy. Restrict amount of drug available to patient. Risk may be increased in children, adolescents, and adults ≤24 yr.
• Monitor BP before and periodically during therapy. Sustained hypertension may be dose-related; decrease dose or discontinue therapy if this occurs.
• Monitor appetite and nutritional intake. Weigh weekly. Report continued weight loss. Adjust diet as tolerated to support nutritional status.
• Assess for serotonin syndrome (mental changes [agitation, hallucinations, coma], autonomic instability [tachycardia, labile BP, hyperthermia], neuromuscular aberrations [hyper-reflexia, incoordination], and/or GI symptoms [nausea, vomiting, diarrhea]), especially in patients taking other serotonergic drugs (SSRIs, SNRIs, triptans).
• Lab Test Considerations: Monitor CBC with differential and platelet count periodically during therapy. May cause anemia, leukocytosis, leukopenia, thrombocytopenia, basophilia, and eosinophilia.
  • May cause an ↑ in serum alkaline phosphatase, bilirubin, AST, ALT, BUN, and creatinine.
  • May also cause ↑ serum cholesterol.
  • May cause electrolyte abnormalities (hyperglycemia or hypoglycemia, hyperkalemia or hypokalemia, hyperuricemia, hyperphosphatemia or hypophosphatemia, and hyponatremia).
  • May cause false-positive immunoassay screening tests for phencyclidine (PCP) and amphetamine.

Potential Nursing Diagnoses

Implementation

• Do not confuse Effexor with Effexor XR.
• Oral: Administer venlafaxine with food.
  • Extended-release capsules should be swallowed whole; do not crush, break, or chew.
  • Extended-release capsules may be opened and contents sprinkled on a spoonful of applesauce. Take immediately and follow with a glass of water. Do not store mixture for later use.

Patient/Family Teaching

• Instruct patient to take venlafaxine as directed at the same time each day. Take missed doses as soon as possible unless almost time for next dose. Do not double doses or discontinue abruptly. Patients taking venlafaxine for >6 wk should have dose gradually decreased before discontinuation.
• Advise patient, family, and caregivers to look for suicidality, especially during early therapy or dose changes. Notify health care professional immediately if thoughts about suicide or dying, attempts to commit suicide; new or worse depression or anxiety; agitation or restlessness; panic attacks; insomnia; new or worse irritability; aggressiveness; acting on dangerous impulses, mania, or other changes in mood or behavior or if symptoms of serotonin syndrome occur.
• May cause drowsiness or dizziness. Caution patient to avoid driving or other activities requiring alertness until response to the drug is known.
• Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and consult health care professional before taking any new medications. Caution patient to avoid taking alcohol or other CNS-depressant drugs during therapy.
• Instruct patient to notify health care professional if signs of allergy (rash, hives) occur.
• Instruct female patients to inform health care professional if pregnancy is planned or suspected or if breast feeding.
• Emphasize the importance of follow-up exams to monitor progress. Encourage patient participation in psychotherapy.

Evaluation/Desired Outcomes

• Increased sense of well-being.
  • Renewed interest in surroundings. Need for therapy should be periodically reassessed. Therapy is usually continued for several months.
• Decreased anxiety.