Varenicline
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Varenicline
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| Systematic (IUPAC) name | |
| 7,8,9,10-tetrahydro-6,10-methano- 6H-pyrazino(2,3-h)(3)benzazepine |
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| Identifiers | |
| CAS number | 375815-87-5 |
| ATC code | N07 |
| PubChem | |
| Chemical data | |
| Formula | C13H13N3 |
| Mol. mass | 211.267 g/mol |
| SMILES | search in , |
| Pharmacokinetic data | |
| Bioavailability | ? |
| Protein binding | <20% |
| Metabolism | Limited (<10%) |
| Half life | 24 hours |
| Excretion | Renal (81–92%) |
| Therapeutic considerations | |
| Licence data |
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| Pregnancy cat. |
C(US) |
| Legal status |
℞ Prescription only |
| Routes | Oral |
Varenicline (Chantix®, Pfizer, usually in the form of varenicline tartrate) is a prescription medication used to treat smoking addiction. By acting similarly to nicotine on the brain it reduces user cravings for cigarettes and other tobacco products and may assist some patients in smoking cessation. In May, 2006, it was approved for sale in the United States. On August 1, 2006, Pfizer announced that Chantix was available for sale in the United States, and on September 29, 2006, it was approved for sale in the European Union with the trade name Champix.
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[edit] Use and dosing
Varenicline is "indicated" for (suggested for use in) smoking cessation. It is an alternative to bupropion (Zyban) and nicotine replacement therapy (NRT), such as nicotine patches.
Varenicline is sold as 0.5 mg and 1 mg tablets. Standard dosing is 1 mg twice daily, with variations as permitted by the FDA. The FDA has approved its use for twelve weeks. If smoking cessation has been achieved it may be continued for another twelve weeks.[1]
Varenicline has not been tested in sub-adults (those under 18) or pregnant women yet, and therefore is not recommended for use by these groups. Women currently breastfeeding should also avoid this product, since varenicline may pass into the breast milk, leading to unknown effects on the child.
[edit] Marketing
An advertisement for Chantix leads viewers to the site http://mytimetoquit.com . Each page of the site contains statistical and scientific information about smoking, addiction, and health and how they intersect. The site is clearly labeled as being presented by Pfizer. Like all advertisements for prescription drugs in the USA, information about the drug itself is not part of the television commercial nor the website advertised therein. The site urges users to "talk to your doctor" about Chantix.
[edit] Mechanism of action
Varenicline is a partial agonist of the α4β2 subtype of the nicotinic acetylcholine receptor. In addition it acts on α3β4 and weakly on α3β2 and α6-containing receptors. A full agonism was displayed on α7-receptors.[2]
[edit] Pharmacokinetics
Most of the active compound is excreted renally (81%). A small proportion is glucuronidated, oxidated, N-formylated or conjugated to a hexose.[3]
[edit] Side-effects
Side-effects include:[1]
[edit] History
Varenicline was selected by Pfizer from a large number of compounds evaluated that showed affinity to the α4β2 nicotinic receptor.[4] It derives chemically from cytisine.
Varenicline received a "priority review" by the U.S. Food and Drug Administration in February 2006, shortening the usual 10-month review period to 6 months because of its demonstrated effectiveness in clinical trials and perceived lack of safety issues.[5] The agency's approval of the drug came on May 11, 2006.[1]
[edit] References
- ^ a b c U.S. Food and Drug Administration. FDA Approves Novel Medication for Smoking Cessation. Press release, 11 May 2006.
- ^ Mihalak KB, Carroll FI, Luetje CW. Varenicline is a partial agonist at α4β2 and a full agonist at α7 neuronal nicotinic receptors. Mol Pharmacol 2006 in press. PMID 16766716.
- ^ Obach RS, Reed-Hagen AE, Krueger SS, Obach BJ, O'Connell TN, Zandi KS, Miller S, Coe JW. Metabolism and disposition of varenicline, a selective alpha4beta2 acetylcholine receptor partial agonist, in vivo and in vitro. Drug Metab Dispos 2006;34:121-30. PMID 16221753.
- ^ Coe JW, Brooks PR, Vetelino MG, Wirtz MC, Arnold EP, Huang J, Sands SB, Davis TI, Lebel LA, Fox CB, Shrikhande A, Heym JH, Schaeffer E, Rollema H, Lu Y, Mansbach RS, Chambers LK, Rovetti CC, Schulz DW, Tingley FD 3rd, O'Neill BT. Varenicline: an alpha4beta2 nicotinic receptor partial agonist for smoking cessation. J Med Chem 2005;48:3474-7. PMID 15887955.
- ^ Kuehn BM. FDA speeds smoking cessation drug review. JAMA 2006;295:614. PMID 16467225.
[edit] External links
