vareniclina

Varenicline is a prescription medication used to help adults quit smoking. It is sold under brand names such as Chantix and Champix and is a selective partial agonist of the alpha4beta2 nicotinic acetylcholine receptor in the brain. By partially activating these receptors, varenicline can lessen withdrawal symptoms and cravings while blocking the rewarding effects of nicotine if smoking resumes, which supports smoking cessation efforts.

Administration and dosing typically follow a structured 12-week regimen. The recommended starting dose is 0.5 mg once daily for the first three days, then 0.5 mg twice daily for days 4 through 7, and thereafter 1 mg twice daily for the remaining weeks. Some patients may continue treatment beyond 12 weeks depending on clinical response. Dose adjustments are advised for moderate to severe renal impairment, and the medication is not routinely recommended during pregnancy or in patients with certain psychiatric conditions unless clearly indicated by a clinician. Caution is advised for individuals with a history of suicidal thoughts or behaviors; patients should report any mood changes, agitation, or unusual sleep disturbances.

Pharmacokinetics and metabolism: After oral administration, varenicline achieves peak plasma concentrations within a few hours and is excreted primarily unchanged in the urine. It is not extensively metabolized by hepatic enzymes, and there are relatively few clinically meaningful drug interactions.

Common adverse effects include nausea, insomnia, abnormal dreams, headache, constipation, and vomiting. More serious but less frequent adverse effects can involve mood or behavior changes and neuropsychiatric symptoms, and patients should seek medical attention if such symptoms occur or worsen.