Classifications: smoking deterrent agent; nicotinic partial agonist; Therapeutic:smoking cessation agent; nicotinic receptor agonist
Pregnancy Category: C
0.5 mg, 1 mg capsules
Nicotine increases dopamine release in the brain and cravings for nicotine are stimulated by low levels of dopamine during
periods of abstinence. Varenicline is a partial agonist at nicotinic acetylcholine receptors (nAChRs), the sites responsible
for the dopamine effects of nicotine. It partially stimulates these receptors to produce a modest level of dopamine but
blocks nicotine from binding to many of the nicotinic receptor sites.
Varenicline binds to nicotinic receptors more potently than nicotine itself. By blocking these receptors, it reduces effects
of nicotine in cases where patient relapses and uses tobacco.
Adjunct for smoking cessation in patients experiencing nicotine withdrawal.
Pregnancy (category C), lactation. Safe use in children or adolescents <18 y is not known.
Renal disease, impaired renal function, renal failure, older adults.
Route & Dosage
Adult: PO Begin with 0.5 mg/d for 3 d, increase to 0.5 mg b.i.d. for 4 d, then increase to 1 mg b.i.d. on day 8. Treatment duration
is 12 wk and may be repeated an additional 12 wk.
Clcr ≤50 mL/min: titrate to 0.5 mg b.i.d. (max)
- Give after a meal with a full glass of water.
- Dose titration over 8 d (from 0.5 mg to 2 mg daily) is recommended to minimize adverse effects.
- Store at 15°30° C (59°86° F).
Adverse Effects (≥1%)Body as a Whole: Fatigue
, flushing, gingivitis, headache, influenza-like symptoms, lethargy, malaise, thirst. CNS: Abnormal dreams,
anorexia, anxiety, asthenia, disturbance in attention, depression
, dizziness, drowsiness, emotional lability, insomnia,
restlessness, sensory disturbance, sleep disorder. CV:
Chest pain, hypertension. GI:
Abdominal pain, constipation,
diarrhea, dyspepsia, flatulence,
gastroesophageal reflux, nausea, vomiting. Metabolic:
Abnormal liver function test, appetite stimulation, weight gain. Musculoskeletal:
Arthralgia, back pain, muscle cramps, musculoskeletal pain, myalgia. Respiratory:
Dyspnea, epistaxis, respiratory disorder, rhinorrhea. Skin:
Hyperhidrosis, pruritus, rash. Special Senses:
Dysgeusia, xerostomia. Urogenital:
Menstrual irregularity, polyuria.
increases systemic exposure to varenicline by 29%.
Complete absorption from GI tract. Peak:
34 h. Distribution:
<20% protein bound. Metabolism:
Primarily eliminated unchanged in the urine. Half-Life:
Assessment & Drug Effects
- Monitor smoking cessation behavior and adverse effects.
- Monitor BP for new-onset hypertension.
- Monitor diabetics for loss of glycemic control.
Patient & Family Education
- Follow directions for taking the drug (see Administration).
- Report persistent nausea, vomiting, or insomnia to a health care provider.