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Chantix nausea: Chantix side effects and how to avoid them

Chantix side effects and how to avoid them

Chantix side effects include nausea, appetite change, and vivid dreams. Learn more about these side effects and the Chantix recall.

Common Chantix side effects | Nausea | Appetite change | Vivid dreams | Serious side effects | Depression | Cardiovascular side effects | How long do side effects last? | Warnings | Interactions | How to avoid side effects

Smoking cessation has an array of benefits, including reductions in cancer rates, lung disease, heart attack and stroke risk, and all-cause mortality. Succeeding with a quit attempt can be exceedingly difficult, but the unique smoking cessation medication Chantix (varenicline) can more than double the chance of success. Zyban (bupropion) and over-the-counter nicotine replacement therapies, such as Nicoderm CQ nicotine patches, are a couple of the alternative options to help quit smoking. 

Chantix attaches to nicotine receptors in the brain as a partial agonist, both reducing the craving for nicotine and blocking the pleasure of smoking. While it is enticing to double the chance of achieving the array of smoke-free health benefits, there are some side effects with Chantix which must be considered. This article will explore Chantix side effects and provide tips for avoiding them.

Common side effects of Chantix

  • Nausea, vomiting, upset stomach, appetite change, or abdominal pain
  • Flatulence, diarrhea, or constipation
  • Dry mouth or taste disturbance
  • Insomnia, abnormal dreams, or sleep disorder
  • Malaise, fatigue, or somnolence (sleepiness)
  • Headache
  • Emotional disturbance
  • Shortness of breath or respiratory disorders
  • Skin rash


The most common adverse reaction to Chantix is nausea, which studies have estimated to occur in about 25% of individuals. Typically, the nausea is mild, occurs within the first two weeks, and often resolves with time. Persistent or worsening nausea or if nausea is accompanied by vomiting, consult your prescriber for medical advice.

Appetite change

One of the biggest concerns amongst smokers who are considering quitting is that they will gain weight. While weight gain after stopping smoking averages five to 10 pounds, individual experiences can vary considerably. In fact, about 20% of those who quit may lose weight. 

Based on the concern regarding weight gain, interest in whether Chantix mitigates or worsens this risk is natural. Chantix users may actually experience either an increase or decrease in appetite, but neither one occurs in more than 5% of users. Ultimately, Chantix does not seem to significantly affect the chance of weight gain with smoking cessation.

Vivid dreams and nightmares

A variety of sleep-related disturbances have been described with Chantix. These disturbances can range from unusual dreams to trouble sleeping. Most commonly, abnormal dreams are experienced by about 10% of those taking the drug, and nightmares or sleep disorders are reported by another 1% to 3%. Small numbers of case reports have described sleepwalking that involved harmful activities. 

Sleep problems may also be an aspect of nicotine withdrawal after quitting smoking. Withdrawal symptoms after smoking cessation may also include cravings to smoke, increased appetite, sadness, irritability, restlessness, and difficulty concentrating.

Serious side effects of Chantix

  • Depression or neuropsychiatric disorder
  • Suicidal behavior or thoughts
  • Homicidal thoughts
  • Hypersensitivity allergic reaction or angioedema (swelling of the face or body)
  • Serious skin reactions such as Stevens-Johnson Syndrome (includes blisters and peeling skin) or erythema multiforme
  • Arrhythmia (heart rhythm problem), heart attack, stroke, or angina (chest discomfort)
  • Seizure
  • Photosensitivity (light sensitivity)
  • Vision changes
  • Anemia or thrombocytopenia (low platelet or clotting cell count)
  • Kidney stones or kidney failure
  • Gastrointestinal bleeding
  • Pancreatitis (pancreas inflammation)
  • Hypokalemia (low potassium level)


Case reports of depressed mood and even suicidal thoughts and aggressive behavior came to light after the release of Chantix. The Food and Drug Administration (FDA) responded by adding a black box warning on Chantix in 2009 about this risk. A subsequent study examined these potential concerns in detail and did not find an elevated risk of these adverse effects compared to other smoking cessation medications or even a placebo. The FDA removed the black box warning from Chantix in 2016.

Cardiovascular side effects

Chantix has labeling that warns about use by those with known cardiovascular disease. The labeling arose due to some study data showing a small increased risk of life-threatening cardiovascular events with Chantix. An analysis of multiple clinical trials did not corroborate this concern, however, as rates of cardiovascular events were similar between those taking and not taking Chantix. Furthermore, the FDA has noted that the benefits and risks of taking Chantix must be considered since smoking cessation is particularly improvement for those with cardiovascular disease.

How long do Chantix side effects last?

The duration of Chantix side effects can vary. Most side effects resolve when the medication is discontinued. In fact, immediate discontinuation is advised if one experiences mood changes while on Chantix. On the contrary, mild nausea may improve with time alone, even if Chantix is continued.

Chantix contraindications and warnings

Chantix is not habit-forming.

Based on the concern for cardiovascular or neurological side effects, an overdose of Chantix warrants emergency medical attention and a call to the Poison Help line at 1-800-222-1222. Case reports are limited, but one report lists a fatality with overdose, although additional factors were present.

Anyone with a history of hypersensitivity (allergy) to varenicline should not take Chantix. Cautious consideration and discussion with a healthcare professional are needed before taking Chantix for anyone with a seizure history or risk, cardiovascular disease, psychiatric illness, alcohol use, or renal impairment (kidney disease) with a creatinine clearance of less than 30 mL/minute. Age is another consideration as Chantix is only used in those 17 years and older. Lack of clinical trials in pregnancy and breastfeeding means that caution is needed before using the drug in these circumstances.

A recall on all brand-name Chantix was announced by Pfizer in 2021.

Chantix interactions

Medications that raise the risk of seizure are the primary drug interaction of note for Chantix and may need to be avoided or modified when taking Chantix. Examples of these medications include amifampridine, bupropion, and tramadol.

Concurrent nicotine use may increase the risk of headaches, nausea, vomiting, and dizziness.

Chantix may increase the effects of alcohol by lowering alcohol tolerance. Therefore, alcohol use should be curtailed or avoided.

How to avoid Chantix side effects

  1. Carefully follow the instructions on taking Chantix, as the dosing is typically initiated at a low dose of 0.5 mg once daily for three days and then twice daily for four days, before increasing to the full 1 mg dose twice daily thereafter. This titration may help to avoid side effects at initiation. If you’re unsure how to take Chantix, ask a pharmacist to review the medication guide with you. The manufacturer also provides drug information.
  2. Set a quit date for stopping smoking, often on day eight of Chantix therapy. However, some healthcare professionals may advise gradual discontinuation or a flexible quit date.
  3. Chantix is usually taken for at least 12 weeks of treatment, but the end of treatment may be individualized.
  4. Take the medication with a full glass of water after a meal to potentially reduce the chance of nausea.
  5. Carefully review your health history with the treating medical provider, especially taking time to discuss any history of cardiovascular or mental health problems.
  6. Avoid concurrent alcohol use.
  7. Immediately tell your healthcare provider or seek medical attention if any mood changes, suicidal ideation, chest pain, or harmful sleep disorders are experienced while taking Chantix.

Titration May Reduce Nausea from Anti-Smoking Drug

Jeff Minerd, Contributing Writer, MedPage Today
August 15, 2006

FARMINGTON, Conn., Aug. 15 — Many patients taking Chantix (varenicline tartrate) to help kick the smoking habit could be spared the side effect of nausea if introduced to the drug gradually, according to researchers here.

Titrating the dose of Chantix during the first week of treatment led to a drop of six to seven percentage points in the proportion of patients who became nauseated, said Cheryl Oncken, M.D., of the University of Connecticut Health Center here.

  • Be aware that this study suggests that titrating doses of Chantix over the course of the first week of therapy may help prevent nausea in some patients who are trying to quit smoking.

Nausea is a common side effect that sometimes causes patients to discontinue treatment, Dr. Oncken and colleagues reported in the Aug. 14-28 issue of the Archives of Internal Medicine. The study was supported by Pfizer, which makes Chantix. Pfizer was involved in all elements of this study, including, but not limited to, the study design and monitoring.

The study included nearly 650 patients who smoked an average of 21 cigarettes per day for an average of 25 years. Participants were randomized to a placebo group or one of four treatment groups: 0.5 mg Chantix non-titrated, 0.5 mg Chantix titrated, 1.0 mg Chantix non-titrated, 1.0 mg Chantix titrated.

In both titrated groups, the dose started out at 0.5 mg once daily. Over the course of seven days, the dose was gradually escalated to the full target dose, given twice-daily. The study followed participants as they attempted to quit smoking for 12 weeks, which is the usual course of treatment with Chantix, and then for an additional 40 weeks for a total follow-up of one year.

During treatment, 42% of the non-titrated 1. 0 mg group became nauseated, versus 34% of the 1.0 mg titrated group (P not given). About 15% of the placebo group had nausea (P

In addition, 23% of the non-titrated 0.5 mg group experienced nausea versus 16% of the titrated 0.5 mg group (P not given). Neither of these nausea rates differed significantly from the placebo rate (P=0.12 for the non-titrated group; P=0.86 for the titrated group).

Although the researchers did not report P values for the different nausea rates in the titrated versus non-titrated dosage groups, they concluded that “titration during the first week of treatment appeared to reduce the incidence of nausea.”

The smoking abstinence rate through week 52 of the study, confirmed by breath measurements of carbon monoxide, was 4% for the placebo group, 22% for all patients receiving 1.0 mg twice daily (PP

Chantix was approved by the FDA last May 11. The drug is thought to be an a4ß2 nicotine receptor antagonist, blocking the rewarding effects of nicotine. But the drug is also believed to be a partial agonist to this receptor, stimulating enough dopamine release to reduce nicotine withdrawal cravings.

In an accompanying editorial in the Archives, Bankole A. Johnson, D.Sc., M.D., Ph.D., of the University of Virginia called Chantix a welcome alternative to nicotine replacement therapy and Zyban (bupropion) for doctors trying to help patients quit smoking.

“Varenicline was well-tolerated and promises to be more effective in clinical practice than bupropion,” Dr. Johnson said. “Now, a smoker who wants help to quit no longer has a legitimate excuse to delay seeking treatment.”

Four of the authors reported a variety of financial relationships with Pfizer and an additional four authors are employees of Pfizer.

Primary Source

Archives of Internal Medicine

Source Reference: Oncken C et al. “Efficacy and safety of the novel selective nicotinic acetycholine receptor partial agonist, varenicline, for smoking cessation.Arch Intern Med 2006; 166:1571-1577.

Secondary Source

Archives of Internal Medicine

Source Reference: Johnson B. “New weapon to curb smoking: No more excuses to delay treatment.” Arch Intern Med 2006; 166:1547-1550.

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Nausea. Symptoms, treatment | Directory KLRTS

Moscow, st. Partizanskaya, 41

medical and rehabilitation center.

What is nausea

Nausea is an unpleasant sensation in the upper third of the abdomen and throat. It is not always a sign of poisoning and sometimes signals more serious pathologies, so this symptom should not be ignored. Attacks of nausea and discomfort are a common occurrence in diseases of the gallbladder, liver, stomach and other organs of the gastrointestinal tract.

Types and causes of occurrence

Nausea does not occur without a cause. Among the main provoking factors, overeating, nervous strain, a side effect when taking certain medications, hormonal disorders, hyperthermia and diseases of the digestive system should be noted.
Based on practice, many visits to a specialist for persistent nausea are associated with a latent course of cholecystitis, gastrointestinal ulcers, gastritis, pancreatitis, intestinal obstruction and individual intolerance to certain foods, colitis, Crohn’s disease, hepatitis, liver failure, biliary dyskinesia, etc.


The majority of visits to the doctor of the Kuntsevo Medical and Rehabilitation Center are associated with attacks of nausea, combined with the following symptoms:

  • vomiting. Mild nausea and vomiting or urge to vomit – fairly common together,
  • abdominal pain,
  • bad breath,
  • chills, trembling and weakness,
  • temperature increase,
  • diarrhea and stool disorder,
  • muscle weakness,
  • dizzy,
  • discoloration of the skin.

Nausea is especially dangerous against the background of lack of air, changes in the color and structure of feces, drowsiness, and fainting. In this case, the specialists of the Kuntsevo Medical and Rehabilitation Center are ready to provide medical assistance in a short time.

Which doctor treats nausea? The doctor accepts by appointment. Anyone can choose the day and time of admission on the site, or by calling.

To make an appointment with a doctor, choose any method:

  • call the clinic +7 (495) 103-99-55,
  • order a callback,
  • leave an application for an appointment, through a convenient form on the website:

IMPORTANT! Nausea only seems to be a minor symptom, which quickly passes and does not lead to serious consequences. This important signal of the body that alarming changes are taking place at some level of regulation should not be underestimated.

In order to understand the problem, determine the causes of the symptom and correct the problem, contact our treatment and rehabilitation center to an experienced and qualified specialist! Our doctors guarantee an individual approach to each patient at reasonable prices. Make an appointment with our doctor and forget about anxiety about nausea!


Methods of treatment

Based on such a list of tests as the study of intestinal microflora, blood and feces, the doctor determines the inflammatory process. This list is supplemented by other examinations depending on the clinical picture.
Taking into account the age of the patient, the results of tests, the patient’s condition, the diagnosis is determined, and treatment is prescribed. The main goal of paid treatment for nausea is to eradicate its cause. For this, etiological and pathogenetic therapy involves taking medications.
If the symptoms do not subside within a few days, then the doctor adjusts the tactics of therapy and prescribes the use of anticholinergics, antipsychotics, H1 blockers, etc. As additional recommendations, he recommends taking warm water with lemon, chewing mints to stop symptoms at an unnecessary moment.

Why we should treat nausea

It is impossible to make a diagnosis without a good diagnosis. The clinic near the Molodezhnaya metro station has all the conditions for examination, treatment of nausea and subsequent recovery of patients. Thanks to the complete set of our center, you do not need to spend a lot of time on analyzes – in our own laboratory, the results are prepared in an hour. Without leaving the walls of the Kuntsevsky Medical and Rehabilitation Center, the patient immediately consults with a gastroenterologist and receives a treatment regimen.


  1. Gastroenterology (reference book). Ed. V.T. Ivashkina, S.I. Rapoport – M .: Publishing house “Russian doctor”, 1998
  2. Communicable diseases: national guidelines. Ed. N.D. Yushchuk, Yu.Ya. Vengerov. M. : GEOTAR-Media, 2009
  3. Yushchuk N.D., Brodov L.E. Acute intestinal infections. Diagnosis and treatment. — M.: Medicine, 2001
  4. Henderson JM. Pathophysiology of the digestive system. Translation from English – M. – St. Petersburg: Binom – Nevsky Dialect, 1997

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Nausea and vomiting

Nausea is a painful sensation in the stomach and throat, which may be accompanied by weakness, excessive salivation, sweating and often precedes vomiting.

Vomiting is a sudden involuntary emptying of the stomach.

Nausea and vomiting are symptoms of many diseases and conditions, from pregnancy to serious pathologies such as brain tumors, epilepsy and myocardial infarction.

In most cases, nausea and vomiting are not harmful to the body. However, prolonged vomiting, often in combination with diarrhea, can lead to severe dehydration and, as a result, disruption of the cardiovascular system, brain, kidneys and other organs. This is especially true for young children, who themselves cannot control the manifestations of dehydration. Pregnant women may experience so-called excessive vomiting of pregnant women, which disrupts the balance of electrolytes in the blood and threatens the life of the mother and fetus.

There are medicines available that can reduce nausea. However, in any case, it is necessary to find out its cause.

Synonyms English

Nausea, emesis, vomiting, vomitus, distaste, sickness, retching, bdelygmia.


The duration of nausea and vomiting, the timing of their onset, and the effect of eating on them depend on their underlying cause. For example, nausea and / or vomiting almost immediately after eating may indicate gastritis (inflammation of the gastric mucosa), within 1-8 hours after eating – poisoning.

Prolonged vomiting may show signs of dehydration:

  • dry mouth;
  • thirst;
  • sunken eyes;
  • infrequent urination, decreased amount of urine, dark urine;
  • in children, the fontanel can sink – a soft area at the junction of the child’s cranial bones, which normally closes by 12-18 months of age.

There are also a number of symptoms that are signs of dangerous, life-threatening conditions and require immediate medical attention:

  • admixture of blood in vomit;
  • severe headache, confusion, impaired consciousness;
  • abdominal pain;
  • signs of dehydration;
  • shortness of breath;
  • Vomiting that lasts more than a day (for children, if it lasts for several hours, especially in combination with diarrhea and fever).

Vomiting and nausea usually resolve within 6-24 hours. If these symptoms recur within a week and if you suspect a possible pregnancy, you should also seek medical advice.

General information about the disease

Nausea occurs when there is a decrease or absence of gastric peristalsis with simultaneous tension of the initial part of the intestine – the duodenum, which is accompanied by the reflux of part of the contents of the duodenum into the stomach. With vomiting, there is a strong contraction of the diaphragm and muscles of the anterior abdominal wall, holding the breath and a sharp release of the contents of the stomach into the esophagus and further into the oral cavity. This may be accompanied by increased salivation, sweating, weakness, dizziness.

Specific centers in the brain are responsible for the occurrence of nausea and vomiting, which receive information from the organs of the gastrointestinal tract, vestibular apparatus, other parts of the brain, kidneys, and also react to the chemical composition of the blood, including toxins, drugs, metabolic products. These centers trigger and control the activity of the muscles involved in nausea and vomiting.

Causes of nausea and vomiting may be as follows.

  • Irritation of the gastric mucosa. In this case, nausea and vomiting are protective reactions of the body aimed at eliminating the damaging agent.
  • Intestinal infections – rotavirus, salmonellosis, botulism, dysentery, etc. – in addition to nausea and vomiting, are accompanied by pain in the abdomen, fever. The most common infection is rotavirus. It is especially common among children attending kindergartens and nurseries, and occurs with nausea, vomiting, diarrhea, which usually lasts 1-2 days. After the disease, immunity is formed.
  • Food poisoning. In this case, vomiting occurs within a few hours after eating.
  • Gastric ulcer – damage to the mucous membrane of the stomach under the action of gastric juice. May be accompanied by belching, heartburn, abdominal pain.
  • Gastroesophageal reflux disease is a chronic disease in which there is a regular reflux of stomach contents into the esophagus with damage to the mucous membrane of the esophagus by acidic gastric juice.
  • Irritation of the stomach by other substances: alcohol, nicotine, aspirin.
  • Effects on the central nervous system and vestibular apparatus. In this case, nausea and vomiting are caused by irritation of certain centers of the brain.
  • An increase in intracranial pressure in brain injuries, tumors, infections (meningitis, encephalitis) may be accompanied by nausea and vomiting.
  • Stimulation of the vestibular apparatus. It includes labyrinthitis (inflammation of the inner ear), motion sickness in transport, and other diseases and conditions in which excessive irritation of the balance organ occurs.
  • Headache, especially in migraine. Migraine is a neurological disease characterized by severe headache, usually on one side, which may be exacerbated by bright lights or loud noises and accompanied by nausea and vomiting.
  • Sunstroke. A condition that occurs when the head is exposed to the sun for a long time. Often found in children. May be accompanied by lethargy, weakness, nausea, vomiting, pallor, disorientation, loss of consciousness.
  • Diseases of other organs – diabetes mellitus, urolithiasis, hepatitis, pancreatitis, certain malignant neoplasms, mental illness (depression, anorexia, bulimia) and other diseases.
  • Medicinal products used in the treatment of cancer, radiotherapy.
  • Pregnancy (first trimester).
  • In children under one year old, vomiting may be a sign of pyloric stenosis, intestinal intussusception, and often accompanies viral diseases (influenza, SARS). Pyloric stenosis is a narrowing or complete obstruction of the opening between the stomach and the duodenum. Intestinal intussusception is a condition in which a segment of the intestine is embedded in the lumen of an adjacent section of the intestine, which leads to the development of intestinal obstruction.

In adults, the most common causes of vomiting and nausea are intestinal infections, food poisoning, motion sickness; in children, intestinal infections, food poisoning, overeating, as well as a severe cough and any illness with a high fever.

Who is at risk?

  • Preschoolers.
  • Pregnant.
  • Undergoing anticancer therapy.
  • People with chronic diseases of the digestive system.
  • People with mental illness.


When determining the cause of nausea and vomiting, their duration, the time of their occurrence, the presence of signs of other diseases and conditions are important. Laboratory and instrumental studies are also important.

Laboratory diagnostics

  • Complete blood count. An increase in white blood cells may indicate an infection as a possible cause of nausea and vomiting. An increase in the number of red blood cells indicates thickening of the blood due to dehydration.
  • ESR. Erythrocyte sedimentation rate. Normally, red blood cells repel each other. With inflammation, the protein composition of the blood changes, electrolytes stick together more easily, and the rate of their sedimentation increases. Thus, an increase in ESR may indicate infection or chronic inflammation as a possible cause of nausea and vomiting.
  • Blood electrolytes
  • Potassium and sodium in blood serum. They participate in the transmission of a nerve impulse, muscle contraction, maintaining the acid-base balance of the blood. A decrease in serum potassium and sodium levels may indicate blood clotting and dehydration. Sodium levels can increase with kidney disease, adrenal dysfunction.
  • Serum calcium. Calcium is involved in the formation of bone tissue, the conduction of a nerve impulse, and the work of some enzymes. A change in its level is a sign of diseases of the kidneys, thyroid gland, parathyroid glands, and some neoplasms.
  • Serum glucose. Glucose is the main source of energy in the body. An increase in its concentration is characteristic of diabetes mellitus. A significant increase in its level may indicate diabetic ketoacidosis, a severe, life-threatening condition that develops with a lack of insulin. Without insulin, the body’s cells cannot use glucose for energy. As a result, the body begins to use fats, the breakdown of which produces toxic substances – ketones. Thus, the level of glucose and ketones in the blood rises. Diabetic ketoacidosis can lead to coma or even death if left untreated.
  • Total amylase in serum. This is an enzyme that is produced in the pancreas and salivary glands. Essential for the digestion of carbohydrates. An increase in the level of amylase may indicate a pathological process in the pancreas.
  • Lipase. An enzyme produced in the pancreas that is involved in the digestion of fats. An elevated lipase concentration is the most specific sign of pancreatic damage.
  • β-subunit of human chorionic gonadotropin (beta-hCG) is a hormone that is produced by the membrane of the embryo and is involved in maintaining pregnancy. A blood test for beta-hCG is used to diagnose pregnancy. Home pregnancy tests are also based on determining its amount in the urine, however, determining its level in the blood is more reliable and can detect pregnancy already on the 6-8th day after fertilization.
  • Urinalysis with microscopy. Dark, concentrated urine can be a sign of dehydration.
  • Sowing feces for flora. Used for suspected intestinal infection.

Other examinations

  • Ultrasound examination (ultrasound), X-ray of the abdominal organs. They are used to assess the state of internal organs and identify the cause of nausea and vomiting.
  • X-ray, computed tomography (CT), magnetic resonance imaging (MRI) of the skull. It is used to diagnose injuries, diseases of the brain.
  • Endoscopic examination of the gastrointestinal tract. This is an examination of the digestive organs with the help of an endoscope – a special device in the form of a tube equipped with an optical system. During endoscopy, you can take a sample of tissue from the wall of the digestive tract for subsequent microscopic examination.
  • Lumbar puncture for suspected diseases of the central nervous system. This is taking a sample of the fluid around the spinal cord. It is carried out after anesthesia. For research, a needle is used, which is inserted between the second and third or third and fourth lumbar vertebrae. The patient at this time sits or lies on his side, the back is maximally bent.
  • Audiometry and electronystagmography. It is used to diagnose diseases of the vestibular apparatus. Audiometry is a test performed by an audiologist to determine hearing acuity. To do this, use a special device audiometer. Electronystagmography is a method of recording involuntary movements of the eyeballs during head movements, temperature changes, which provides information about the state of the vestibular apparatus.
  • Electroencephalography (EEG) is a study of the electrical activity of the brain using sensors that are placed on the head. It is carried out with suspicion of a neurological or mental pathology. This way evaluate the state of the brain, its response to stimuli.


Treatment depends on the underlying cause of the nausea and vomiting.