Varenicline

Last updated

Varenicline
Varenicline.svg
Varenicline ball-and-stick model.png
Clinical data
Pronunciation /vəˈrɛnɪkln/ və-REN-i-kleen
Trade names Champix, Chantix, Tyrvaya, others
Other namesOC-01
AHFS/Drugs.com Monograph
MedlinePlus a606024
License data
Pregnancy
category
  • AU:B3
Routes of
administration
By mouth, intranasal
Drug class Nicotinic agonist
ATC code
Legal status
Legal status
Pharmacokinetic data
Protein binding <20%
Metabolism Limited (<10%)
Elimination half-life 24 hours
Excretion Kidney (81–92%)
Identifiers
  • 7,8,9,10-Tetrahydro-6,10-methano-6H-pyrazino[2,3-h] [3]benzazepine
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
CompTox Dashboard (EPA)
Chemical and physical data
Formula C13H13N3
Molar mass 211.268 g·mol−1
3D model (JSmol)
  • n1c2cc3c(cc2ncc1)[C@@H]4CNC[C@H]3C4
  • InChI=1S/C13H13N3/c1-2-16-13-5-11-9-3-8(6-14-7-9)10(11)4-12(13)15-1/h1-2,4-5,8-9,14H,3,6-7H2/t8-,9+ Yes check.svgY
  • Key:JQSHBVHOMNKWFT-DTORHVGOSA-N Yes check.svgY
 X mark.svgNYes check.svgY  (what is this?)    (verify)

Varenicline, sold under the brand names Chantix and Champix among others, is a medication used for smoking cessation [5] [7] and for the treatment of dry eye syndrome. [6] [8] It is a nicotinic acetylcholine receptor partial agonist. [5] [6] When activated, this receptor releases dopamine in the nucleus accumbens, the brain's reward center, thereby reducing cravings and withdrawal symptoms with smoking cessation, although less pronounced than a full agonist (i.e., nicotine). [9]

Contents

Common side effects include nausea, insomnia, abnormal dreams, headache, and nasopharyngitis (inflammation of the nose and throat). [7] Despite these potential adverse effects, varenicline has proven efficacy in helping individuals quit smoking. It is estimated that approximately one in eleven smokers who use varenicline successfully remain abstinent from tobacco at six months. [10]

It is on the World Health Organization's List of Essential Medicines. [11] The medication is available as a generic medication. [12] In the United States, varenicline was prescribed over 1 million times in 2020, ranking as the 275th most commonly prescribed medication. [13] [14]

Medical uses

Varenicline is indicated for use as an aid to smoking cessation treatment [5] and for the treatment of the signs and symptoms of dry eye disease. [6]

Varenicline is used to help people stop smoking tobacco (smoking cessation). A meta-analysis found that 20% of people treated with varenicline remain abstinent from smoking at one year. [15] In a 2009 meta-analysis, varenicline was found to be more effective than bupropion (odds ratio 1.40) and nicotine replacement therapies (NRT) (odds ratio 1.56). [16]

A 2013 Cochrane overview and network meta-analysis concluded that varenicline is the most effective medication for tobacco cessation and that smokers were nearly three times more likely to quit tobacco use while on varenicline than with placebo treatment. Varenicline was more efficacious than bupropion or NRT and as effective as combination NRT for cessation of tobacco smoking. [17] [18]

Side effects

Mild nausea is the most common side effect and is seen in approximately 30% of people taking varenicline, though this rarely (<3%) results in discontinuation of the medication. [18] Other less common side effects include headache, difficulty sleeping, and vivid dreams. Rare side effects reported by people taking varenicline compared to placebo include change in taste, vomiting, abdominal pain, flatulence, and constipation. It has been estimated that for every five subjects taking varenicline at maintenance doses, there will be one event of nausea; and for every 24 of 35 treated subjects, there will be an event of constipation or flatulence. Gastrointestinal side-effects lead to discontinuation of the drug in 2% to 8% of people using varenicline. [19] [20] Incidence of nausea is dose-dependent: incidence of nausea was higher in people taking a larger dose (30%) versus placebo (10%) as compared to people taking a smaller dose (16%) versus placebo (11%). [5]

Depression and suicide

In 2007, the US Food and Drug Administration (FDA) announced it had received post-marketing reports of thoughts of suicide and occasional suicidal behavior, erratic behavior, and drowsiness among people using varenicline for smoking cessation. In 2009, the FDA required varenicline to carry a boxed warning that the medication should be stopped if any of these symptoms are experienced. [21]

A 2014 systematic review (literature research) did not find evidence of an increased suicide risk. [22] Other analyses have reached the same conclusion and found no increased risk of neuropsychiatric side effects with varenicline. [17] [18] No evidence for increased risks of cardiovascular events, depression, or self-harm with varenicline versus nicotine replacement therapy was found in one post-marketing surveillance study. [23]

In 2016, the FDA removed the black box warning. [24] People are still advised to stop the medication if they "notice any side effects on mood, behavior, or thinking." [24] [25] [26]

Cardiovascular disease

In June 2011, the US FDA issued a safety announcement that varenicline may be associated with "a small, increased risk of certain cardiovascular adverse events in people who have cardiovascular disease." [27]

A prior 2011 review had found increased risk of cardiovascular events compared with placebo. [28] Expert commentary in the same journal raised doubts about the methodology of the review, [29] [30] concerns which were echoed by the European Medicines Agency and subsequent reviews. [31] [32] Of specific concern were "the low number of events seen, the types of events counted, the higher drop-out rate in people receiving placebo, the lack of information on the timing of events, and the exclusion of studies in which no-one had an event."

In contrast, multiple recent systematic reviews and meta-analyses have found no increase in overall or serious adverse cardiovascular events (including for individuals at risk of developing cardiovascular disease) associated with varenicline use. [32] [33] [34] [35]

Mechanism of action

Varenicline displays full agonism on α7 nicotinic acetylcholine receptors and is a partial agonist on the α4β2, α3β4, and α6β2 subtypes. [36] [37] [38]

Varenicline's partial agonism on the α4β2 receptors rather than nicotine's full agonism produces less effect of dopamine release than nicotine's. This α4β2 competitive binding reduces the ability of nicotine to bind and stimulate the mesolimbic dopamine system—similar to the method of action of buprenorphine in the treatment of opioid addiction. [18]

Pharmacokinetics

Most of the active compound is excreted by the kidneys (92–93%). A small proportion is glucuronidated, oxidised, N-formylated or conjugated to a hexose. [39]

History

Use of Cytisus plants as a smoking substitute during World War II [40] led to use as a cessation aid in eastern Europe and extraction of cytisine. [41] Cytisine analogs led to varenicline at Pfizer. [42] [43] [44]

Varenicline received a priority review by the US FDA in February 2006, shortening the usual ten-month review period to six months because of its demonstrated effectiveness in clinical trials and perceived lack of safety issues. [45] The agency's approval of the drug came in May 2006. [46] [47] In September 2006, it was approved for sale in the European Union. [7]

In September 2021, Pfizer announced a recall of "all lots of its anti-smoking treatment, Chantix [Varenicline], due to high levels of cancer-causing agents called nitrosamines in the pills". [48] This followed a July 2021 announcement by the FDA that it was "alerting patients and health care professionals to Pfizer's voluntary recall of nine lots of the smoking cessation drug" and further recalls by Pfizer on 19 July and 8 August. [49] In June 2021, Pfizer paused distribution of Chantix worldwide; [50] "the distribution halt was out of an abundance of caution, pending further testing", the company said in an email. [51] According to the Pfizer Inc. 2020 Form 10-K Annual Report, high-revenue products by the company include[d] Chantix/Champix (varenicline) to treat nicotine addiction, which recorded direct product revenues of more than $1 billion in 2019, $919 million in 2020, and $398 million in 2021 (the lower 2021 revenue was due, in part, to the basic product patent expiration for Chantix in the US in November 2020 and in Europe in September 2021, and the aforementioned Pfizer voluntary recall across multiple markets and a global pause in shipments of Chantix). [52] [53]

In October 2021, the US FDA approved Oyster Point Pharma to market Tyrvaya as a new route of varenicline administration through nasal spray for the treatment of dry eye disease. [54]

Related Research Articles

<span class="mw-page-title-main">Nicotine</span> Chemical stimulant produced by some plants

Nicotine is a naturally produced alkaloid in the nightshade family of plants and is widely used recreationally as a stimulant and anxiolytic. As a pharmaceutical drug, it is used for smoking cessation to relieve withdrawal symptoms. Nicotine acts as a receptor agonist at most nicotinic acetylcholine receptors (nAChRs), except at two nicotinic receptor subunits where it acts as a receptor antagonist.

<span class="mw-page-title-main">Smoking cessation</span> Process of discontinuing tobacco smoking

Smoking cessation, usually called quitting smoking or stopping smoking, is the process of discontinuing tobacco smoking. Tobacco smoke contains nicotine, which is addictive and can cause dependence. As a result, nicotine withdrawal often makes the process of quitting difficult.

<span class="mw-page-title-main">Bupropion</span> Medication mainly used for depression and smoking cessation

Bupropion, formerly called amfebutamone, and sold under the brand name Wellbutrin among others, is an atypical antidepressant primarily used to treat major depressive disorder and to support smoking cessation. It is also popular as an add-on medication in the cases of "incomplete response" to the first-line selective serotonin reuptake inhibitor (SSRI) antidepressant. Bupropion has several features that distinguish it from other antidepressants: it does not usually cause sexual dysfunction, it is not associated with weight gain and sleepiness, and it is more effective than SSRIs at improving symptoms of hypersomnia and fatigue. Bupropion, particularly the immediate release formulation, carries a higher risk of seizure than many other antidepressants, hence caution is recommended in patients with a history of seizure disorder. The medication is taken by mouth.

<span class="mw-page-title-main">Rosiglitazone</span> Chemical compound

Rosiglitazone is an antidiabetic drug in the thiazolidinedione class. It works as an insulin sensitizer, by binding to the PPAR in fat cells and making the cells more responsive to insulin. It is marketed by the pharmaceutical company GlaxoSmithKline (GSK) as a stand-alone drug or for use in combination with metformin or with glimepiride. First released in 1999, annual sales peaked at approximately $2.5-billion in 2006; however, following a meta-analysis in 2007 that linked the drug's use to an increased risk of heart attack, sales plummeted to just $9.5-million in 2012. The drug's patent expired in 2012.

<span class="mw-page-title-main">Atenolol</span> Beta blocker medication

Atenolol is a beta blocker medication primarily used to treat high blood pressure and heart-associated chest pain. Although used to treat high blood pressure, it does not seem to improve mortality in those with the condition. Other uses include the prevention of migraines and treatment of certain irregular heart beats. It is taken orally or by intravenous injection. It can also be used with other blood pressure medications.

<span class="mw-page-title-main">Nicotine replacement therapy</span> Treatment for tobacco use disorder

Nicotine replacement therapy (NRT) is a medically approved way to treat people with tobacco use disorder by taking nicotine through means other than tobacco. It is used to help with quitting smoking or stopping chewing tobacco. It increases the chance of quitting tobacco smoking by about 55%. Often it is used along with other behavioral techniques. NRT has also been used to treat ulcerative colitis. Types of NRT include the adhesive patch, chewing gum, lozenges, nose spray, and inhaler. The use of multiple types of NRT at a time may increase effectiveness.

<span class="mw-page-title-main">Nicotine patch</span> Transdermal patch that releases nicotine into the body

A nicotine patch is a transdermal patch that releases nicotine into the body through the skin. It is used in nicotine replacement therapy (NRT), a process for smoking cessation. Endorsed and approved by the U.S. Food and Drug Administration (FDA), it is considered one of the safer NRTs available for the treatment of tobacco use disorder.

Nicotine gum is a chewing gum containing the active ingredient nicotine polacrilex. It is a type of nicotine replacement therapy (NRT) used alone or in combination with other pharmacotherapy for smoking cessation and for quitting smokeless tobacco.

<span class="mw-page-title-main">Boxed warning</span> Type of warning that appears on the package insert for certain prescription drugs

In the United States, a boxed warning is a type of warning that appears near the beginning of the package insert for certain prescription drugs, so called because the U.S. Food and Drug Administration specifies that it is formatted with a 'box' or border around the text to emphasize it is of utmost importance. The FDA can require a pharmaceutical company to place a boxed warning. It is the strongest warning that the FDA requires, and signifies that medical studies indicate that the drug carries a significant risk of preventable, serious or even life-threatening adverse effects.

<span class="mw-page-title-main">Guanfacine</span> Medication used for high blood pressure and ADHD

Guanfacine, sold under the brand name Tenex (immediate-release) and Intuniv (extended-release) among others, is an oral alpha-2a agonist medication used to treat attention deficit hyperactivity disorder (ADHD) and high blood pressure. Guanfacine is FDA-approved for monotherapy treatment of ADHD, as well as being used for augmentation of other treatments, such as stimulants. Guanfacine is also used off-label to treat tic disorders, anxiety disorders, and post-traumatic stress disorder (PTSD).

<span class="mw-page-title-main">Cytisine</span> Chemical compound

Cytisine, also known as baptitoxine, cytisinicline, or sophorine, is an alkaloid that occurs naturally in several plant genera, such as Laburnum and Cytisus of the family Fabaceae. It has been used medically to help with smoking cessation. It has been found effective in several randomized clinical trials, including in the United States and New Zealand, and is being investigated in additional trials in the United States and a non-inferiority trial in Australia in which it is being compared head-to-head with the smoking cessation aid varenicline. It has also been used entheogenically via mescalbeans by some Native American groups, historically in the Rio Grande Valley predating even peyote.

<span class="mw-page-title-main">Nicotine dependence</span> Chronic disease

Nicotine dependence is a state of substance dependence on nicotine. It is a chronic, relapsing disease characterized by a compulsive craving to use the drug despite social consequences, loss of control over drug intake, and the emergence of withdrawal symptoms. Tolerance is another component of drug dependence. Nicotine dependence develops over time as an individual continues to use nicotine. While cigarettes are the most commonly used tobacco product, all forms of tobacco use—including smokeless tobacco and e-cigarette use—can cause dependence. Nicotine dependence is a serious public health problem because it leads to continued tobacco use and the associated negative health effects. Tobacco use is one of the leading preventable causes of death worldwide, causing more than 8 million deaths per year and killing half of its users who do not quit. Current smokers are estimated to die an average of 10 years earlier than non-smokers.

<span class="mw-page-title-main">Dianicline</span> Chemical compound

Dianicline (SSR-591,813) is a drug developed by Sanofi-Aventis which acts as a partial agonist at neural nicotinic acetylcholine receptors. It is subtype-selective, binding primarily to the α4β2 subtype. It is being developed as a medication for the treatment of nicotine dependence to assist in smoking cessation. Dianicline is very similar to the already marketed drug varenicline and it is unclear what advantages it will have over the older drug, although it may have an improved side effect profile. It has been through human trials up to Phase II, although results have not yet been reported. Drug development has been discontinued after reporting of unfavourable results during Phase III trials.

Glucagon-like peptide-1 (GLP-1) receptor agonists, also known as GLP-1 analogs, GLP-1DAs or incretin mimetics, are a class of anorectic drugs that reduce blood sugar and energy intake by activating the GLP-1 receptor. They mimic the actions of the endogenous incretin hormone GLP-1 that is released by the gut after eating.

Schizophrenia and tobacco smoking have been historically associated. Smoking is known to harm the health of people with schizophrenia.

<span class="mw-page-title-main">Dulaglutide</span> Diabetes medication

Dulaglutide, sold under the brand name Trulicity among others, is a medication used for the treatment of type 2 diabetes in combination with diet and exercise. It is also approved in the United States for the reduction of major adverse cardiovascular events in adults with type 2 diabetes who have established cardiovascular disease or multiple cardiovascular risk factors.

SGLT2 inhibitors are a class of medications that inhibit sodium-glucose transport proteins in the nephron, unlike SGLT1 inhibitors that perform a similar function in the intestinal mucosa. The foremost metabolic effect of this is to inhibit reabsorption of glucose in the kidney and therefore lower blood sugar. They act by inhibiting sodium/glucose cotransporter 2 (SGLT2). SGLT2 inhibitors are used in the treatment of type 2 diabetes. Apart from blood sugar control, gliflozins have been shown to provide significant cardiovascular benefit in people with type 2 diabetes. As of 2014, several medications of this class had been approved or were under development. In studies on canagliflozin, a member of this class, the medication was found to enhance blood sugar control as well as reduce body weight and systolic and diastolic blood pressure.

Jed Eugene Rose is an American academic professor, inventor and researcher in the field of nicotine and smoking cessation. Rose is presently the President and CEO of the Rose Research Center, LLC in Raleigh, North Carolina. Additionally, he is the Director of the Duke Center for Smoking Cessation at Duke University Medical Center.

<span class="mw-page-title-main">Semaglutide</span> Anti-diabetic and anti-obesity medication

Semaglutide is an antidiabetic medication used for the treatment of type 2 diabetes and an anti-obesity medication used for long-term weight management. It is a peptide similar to the hormone glucagon-like peptide-1 (GLP-1), modified with a side chain. It can be administered by subcutaneous injection or taken orally. It is sold under the brand names Ozempic and Rybelsus for diabetes, and under the brand name Wegovy for weight loss.

Nicotine vaccine is a novel immunological strategy for treating nicotine addiction. Nicotine vaccine uses active immunization as the methodology to create polyclonal antibodies to the antigens, which is then used to treat drug abuse. The immune system is then able to identify nicotine as a foreign substance and initiate an immune reaction targeting the drug. As a result, the quantity of nicotine that enters the brain would decrease after receiving the vaccine. In preclinical studies, nicotine vaccines have demonstrated the ability to combat the negative effects of nicotine abuse, but none of the developed vaccines has been authorized for use in clinical trials as a smoking cessation strategy. Theoretically, the decrease of nicotine's rewarding effects should result in smoking cessation. Some companies have tested candidate vaccines in clinical trials, but evidence failed to show the adequate antibody responses or exhibit superior efficacy to factors concerning placebo.

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