Read Mosby's 2014 Nursing Drug Reference Online
Authors: Linda Skidmore-Roth
Potent inhibitor of neuronal serotonin and norepinephrine uptake, weak inhibitor of dopamine; no muscarinic, histaminergic, or α-adrenergic receptors in vitro
Prevention/treatment of major depression; depression at the end of life; long-term treatment of general anxiety disorder, panic disorder, social anxiety disorder (Effexor XR only)
Unlabeled uses:
Hot flashes, premenstrual dysphoric disorder (PMDD), headache, neuropathic pain, fibromyalgia, diabetic neuropathy
Hypersensitivity, bipolar disorder, interstitial lung disease
Precautions:
Pregnancy (C), breastfeeding, geriatric patients, mania, hypertension, seizure disorder, recent MI, cardiac/renal/hepatic disease, eosinophilic pneumonia, desvenlafaxine hypersensitivity
Black Box Warning:
Children, suicidal ideation
• Adult:
PO
75 mg/day in 2-3 divided doses; taken with food, may be increased to 150 mg/day; if needed, may be further increased to 225 mg/day; increments of 75 mg/day at intervals of ≥4 days; some hospitalized patients may require up to 375 mg/day in 3 divided doses;
EXT REL
37.5-75 mg PO daily, max 225 mg/day; give XR daily
• Adult:
PO
75 mg/day or 37.5 mg/day × 4-7 days initially, max 225 mg/day
• Adult:
PO
CCr 10-70 ml/min, reduce dose by 25%-50%; CCr <10 ml/min, reduce dose by 50%
• Adult:
PO
Moderate impairment, 50% of dose
• Adult (male, prostate cancer):
PO
12.5 mg bid × 4 wk; females 37.5-75 mg/day
• Adult:
PO
37.5-75 mg/day, max 75 mg bid (regular rel) or 150 mg/day (ext rel)
• Adult female:
PO
50-200 mg/day, start at 50 mg/day for 1st cycle, titrate upward
Available forms:
Tabs scored 25, 37.5, 50, 75, 100 mg; ext rel cap (Effexor XR) 37.5, 75, 150 mg; ext rel tab 37.5, 75, 150, 225 mg
•
With food, milk for GI symptoms; do not crush, chew caps; caps can be opened and contents sprinkled on applesauce, given with full glass of water
•
Sugarless gum, hard candy, frequent sips of water for dry mouth
•
Avoid use with CNS depressants
•
In small amounts because of suicide potential, especially at beginning of therapy
CNS:
Emotional lability,
vertigo, dizziness, weakness
, apathy, ataxia, CNS stimulation, euphoria, hallucinations, hostility, increased libido, hypertonia, hypotonia, psychosis, insomnia, anxiety,
suicidal ideation in children/adolescents, seizures, neuroleptic-malignant-syndrome–like reaction
CV:
Migraine
, angina pectoris, hypertension,
sustained hypertension, change in QTc interval,
increased pulse, increased cholesterol, extrasystoles, postural hypotension, syncope, thrombophlebitis
EENT:
Abnormal vision
, taste,
ear pain
, cataract, conjunctivitis, corneal lesions, dry eyes, otitis media, photophobia
GI:
Dysphagia, eructation
, nausea, anorexia, dry mouth, colitis, gastritis, gingivitis,
rectal hemorrhage,
stomatitis, stomach and mouth ulceration
GU:
Anorgasmia
, abnormal ejaculation,
dysuria, hematuria, metrorrhagia, vaginitis, impaired urination
, albuminuria, amenorrhea, kidney calculus, cystitis, nocturia, breast and bladder pain, polyuria,
uterine hemorrhage, vaginal hemorrhage,
moniliasis
HEMA:
Agranulocytosis, aplastic anemia, neutropenia, pancytopenia, abnormal bleeding
INTEG:
Ecchymosis, acne, alopecia, brittle nails, dry skin, photosensitivity, sweating,
angioedema (ext rel)
META:
Peripheral edema, weight loss or gain
, diabetes mellitus, edema, glycosuria, hyperlipemia, hypokalemia
MS:
Arthritis, bone pain, bursitis, myasthenia, tenosynovitis, arthralgia
RESP:
Bronchitis, dyspnea
, asthma, chest congestion, epistaxis, hyperventilation, laryngitis
SYST:
Malaise, neck pain
, enlarged abdomen, cyst, facial edema, hangover, hernia
Well absorbed; extensively metabolized in liver by CYP2D6 to active metabolite; 87% of product recovered in urine; 27% protein binding; half-life 5, 11 hr (active metabolite), respectively
Hyperthermia, rigidity, rapid fluctuations of vital signs, mental status changes, neuroleptic malignant syndrome: MAOIs
Increase:
bleeding risk—salicylates, NSAIDs, platelet inhibitors, anticoagulants
Increase:
venlafaxine effect—cimetidine
Increase:
CNS depression—alcohol, opioids, antihistamines, sedative/hypnotics
Increase:
levels of cloZAPine, desipramine, haloperidol, warfarin
Increase:
serotonin syndrome—sibutramine, SUMAtriptan, traZODone, traMADol, SSRIs, serotonin receptor agonist, linezolid, methylene blue, tryptophan
Decrease:
effect of indinavir
Decrease:
venlafaxine effect—cyproheptadine
•
Serotonin syndrome: St. John’s wort, tryptophan
Increase:
CNS depression—kava, valerian
Increase:
alk phos, bilirubin, AST, ALT, BUN, creatinine, serum cholesterol, CPK, LDH
False positive:
amphetamines, phencyclidine
Black Box Warning:
Mental status: mood, sensorium, affect, increase in psychiatric symptoms; depression, panic; assess for suicidal ideation in children/adolescents
•
B/P lying, standing; pulse q4hr; if systolic B/P drops 20 mm Hg, hold product, notify prescriber; take VS q4hr in patients with CV disease
Bleeding:
GI, ecchymosis, epistaxis, hematomas, petechiae, hemorrhage
•
Blood studies: CBC, differential, leukocytes, cardiac enzymes if patient is receiving long-term therapy
•
Hepatic studies: AST, ALT, bilirubin
•
Weight weekly; weight loss or gain; appetite may increase; peripheral edema may occur; monitor cholesterol
•
Withdrawal symptoms:
flulike symptoms, headache, nervousness, agitation, nausea, vomiting, muscle pain, weakness; not usual unless product is discontinued abruptly
Serotonin syndrome, neuroleptic malignant syndrome:
increased heart rate, shivering, sweating, dilated pupils, tremors, high B/P, hyperthermia, head
ache, confusion; if these occur, stop product, administer serotonin antagonist if needed, usually worse if given with linezolid, methylene blue, tryptophan
•
Storage in tight container at room temp; do not freeze
•
Assistance with ambulation during beginning therapy because drowsiness, dizziness occur
•
Therapeutic response: decreased depression, anxiety; increased well-being
•
To notify prescriber of rash, hives, allergic reactions, bleeding
•
To use with caution when driving, performing other activities requiring alertness because of drowsiness, dizziness, blurred vision
Black Box Warning:
That worsening of symptoms, suicidal thoughts/behaviors may occur in children/young adults
•
To avoid alcohol ingestion
•
Not to discontinue medication abruptly after long-term use; may cause nausea, headache, malaise
•
To wear sunscreen or large hat because photosensitivity occurs
•
To avoid pregnancy or breastfeeding while taking this product, birth defects have occurred when used in the 3rd trimester
•
To monitor B/P with hypertension
ECG monitoring; lavage, activated charcoal; administer anticonvulsant; may require whole-bowel irrigation for ext rel product
Canada only Side effects:
italics
= common;
bold
= life-threatening
Nurse Alert