This article describes possible side effects of varenicline oral tablet. To learn more about varenicline, including the drug’s uses, dosage, and more, talk with your doctor or pharmacist.
Varenicline oral tablet is a generic medication. It isn’t available in a brand-name version. Varenicline also comes in a nasal spray, but this article does not describe this form. To learn more about this form, talk with your doctor.
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More common side effects of varenicline
Varenicline oral tablet may cause mild or serious side effects. Below are some of the more common side effects of this medication.
Commonly reported side effects of varenicline oral tablet include:
- constipation
- gas
- strange, unusual, or vivid dreams
- vomiting
- mild nausea*
- mild sleep problems*
* To learn more about this side effect, see the “Side effects of varenicline in detail” section below.
Mild side effects of varenicline
Varenicline may cause certain mild side effects. Usually, mild side effects are temporary and easily manageable. Tell your doctor or pharmacist if you have side effects that don’t go away or become bothersome.
Mild side effects of varenicline oral tablet that occurred in studies include:
- abdominal pain or discomfort
- bloating
- changes in appetite
- changes in the sense of taste
- constipation
- drowsiness
- dry mouth
- gas
- headache
- indigestion
- lack of energy
- strange, unusual, or vivid dreams
- vomiting
- mild nausea*
- mild sleep problems*
- mild allergic reaction*
* To learn more about this side effect, see the “Side effects of varenicline in detail” section below.
Varenicline oral tablet may cause more mild side effects than those listed above. For details, see the drug’s prescribing information.
Serious side effects of varenicline
Varenicline may cause certain serious side effects. If you have any serious side effects from varenicline oral tablet, call your doctor right away. But if you think you’re having a medical emergency or your side effects feel life threatening, take immediate action. Call 911 or a local emergency number, or go to the nearest emergency room.
After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Visit MedWatch’s website if you’d like to notify the FDA about a side effect you’ve had with varenicline.
Serious side effects of varenicline oral tablet that occurred in studies include:
- new or worsening mental health conditions, including suicidal thoughts or actions
- seizures
- serious skin reaction
- severe nausea*
- severe sleep problems*
- new or worsening heart or blood vessel problems*
- severe allergic reaction*
* To learn more about this side effect, see the “Side effects of varenicline in detail” section below.
Suicide prevention
If you or someone you know is in crisis and considering suicide or self-harm, please seek support:
- Call the 988 Suicide and Crisis Lifeline at 988.
- Text HOME to the Crisis Text Line at 741741.
- Not in the United States? Find a helpline in your country with Befrienders Worldwide.
- Call 911 or your local emergency services number if you feel safe to do so.
If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.
If you are not in the same household, stay on the phone with them until help arrives.
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Get free cardCommon questions about side effects of varenicline
Here are answers to some common questions about side effects of varenicline oral tablet. If you have other questions, talk with your doctor or pharmacist.
Does varenicline cause long-term side effects?
Yes, in some cases varenicline oral tablet may cause long-term side effects. These can occur if you take the drug for a long time.
Examples of long-term side effects reported with varenicline oral tablet include:
- nausea, which can happen throughout treatment
- seizures, which can happen even if you’ve taken varenicline before and didn’t have seizures
Talk with your doctor if you have more questions about possible long-term side effects with varenicline.
Is dependence a possible side effect of varenicline?
Dependence isn’t likely with varenicline oral tablet. With dependence, your body needs the drug in order to function like usual. Drugs that have a high risk of dependence are usually listed as controlled substances. The federal government regulates these drugs. Varenicline oral tablet is not a controlled substance.
However, in studies, a small amount of people taking varenicline oral tablet had withdrawal symptoms when they stopped taking it suddenly. These included irritability and sleep problems. Withdrawal symptoms can occur if your body is dependent on a drug and you stop taking it. So its possible that some people may be mildly dependent on varenicline oral tablet. But more research is needed to determine whether varenicline causes dependence.
If you have concerns about dependence with varenicline oral tablet, talk with your doctor. To learn more about sleep problems with this drug, see the “Side effects of varenicline in detail” section below.
Side effects of varenicline in detail
Below you’ll find details on some of the side effects of varenicline oral tablet.
Nausea
In studies, nausea was the most common side effect in people taking varenicline oral tablet. This side effect is usually mild, but may be serious in some cases.
For most people, nausea was mild to moderate and went away over time. But for others, it continued for several months. Nausea was the most common reason for stopping varenicline oral tablet.
Nausea with varenicline oral tablet is dose-dependent. This means it is more likely to occur at higher doses.
Ways to manage
Due to the risk of nausea, doctors usually start with a low dose of varenicline oral tablet. Then, they’ll increase it over time. This helps reduce the risk of nausea.
If you experience nausea that becomes severe or unbearable, tell your doctor. They’ll likely recommend reducing your dose. Don’t change your dosage of varenicline oral tablet without talking with your doctor.
Sleep problems
In studies, sleep problems were common in people taking varenicline oral tablet. This side effect is usually mild, but may be serious in some cases.
Sleep problems reported with varenicline oral tablet include:
- insomnia (trouble getting to sleep or staying asleep)
- unusual dreams, which includes strange or vivid dreams
- sleepwalking, which can cause harm to yourself, other people, or property without you remembering what happened
Insomnia and uusual dreams were common reasons for stopping varenicline oral tablet.
Ways to manage
If you experience insomnia or unusual dreams, tell your doctor. They may be able to suggest ways to manage these problems. If you experience sleepwalking, stop taking varenicline oral tablet and let your doctor know right away.
New or worsening heart or blood vessel problems
In studies, new or worsening heart or blood vessel problems were rare in people taking varenicline oral tablet. But this side effect may be serious.
Heart or blood vessel problems that can occur with varenicline oral tablet include heart attack and stroke, which can be life threatening. These problems mostly happened in people who already had heart or blood vessel disease.
Symptoms of a heart attack or stroke may include:
- chest pain, discomfort, or pressure
- pain that spreads to the neck, shoulder, back, or arm
- shortness of breath
- sudden problems speaking or understanding language
- sudden weakness on one side of the body or face
Ways to manage
If you experience symptoms of a heart attack or stroke, get emergency medical care immediately. Call 911 or your local emergency number. If you experience a heart attack or stroke while taking varenicline oral tablet, your doctor will likely recommend you stop taking the drug.
However, the benefits of quitting smoking may still outweigh the risks of heart or blood vessel problems. Your doctor can best advise you about what these risks means for you.
Allergic reaction
For some people, varenicline oral tablet can cause an allergic reaction.
Symptoms can be mild or serious, and they may include:
- itchiness
- skin rash
- severe skin rashes that may blister or peel
- swelling under the skin, usually affecting eyelids, lips, hands, or feet
- swelling of the mouth, tongue, or throat, which can make it hard to breathe
- flushing (temporary warmth, redness, or deepening of skin color)
Ways to manage
For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.
For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to varenicline oral tablet, your doctor may recommend taking a different medication instead.
Warnings for varenicline
Below are some factors you may want to discuss with your doctor before taking varenicline oral tablet.
Warnings
It may not be safe for you to take varenicline oral tablet if you have specific health conditions. These are sometimes called drug-condition interactions. Other things may also affect whether varenicline oral tablet is a safe option for you.
Before taking varenicline oral tablet, tell your doctor about your health and the medications you take. Things to consider include:
- alcohol use
- heart or blood vessel disease
- kidney disease
- mental health conditions
- seizures or epilepsy
- past allergic reaction to varenicline
Varenicline and pregnancy
It is unknown whether you should take varenicline oral tablet during pregnancy. If you’re planning a pregnancy or can become pregnant, talk with your doctor before taking this medication.
Varenicline and breastfeeding
It is unknown whether you should take varenicline oral tablet while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before taking this medication.
Varenicline and alcohol
Varenicline oral tablet is known to interact with alcohol.
This interaction wasn’t seen during studies of varenicline oral tablet. But people taking varenicline oral tablet after the drug was approved for use have reported this interaction.
Drinking alcohol while taking varenicline can increase the intoxicating effects of alcohol. There have also been reports of people having unusual or aggressive behavior and not remembering it the next day.
If you drink alcohol, talk with your doctor about whether it’s safe to consume it while taking varenicline oral tablet.
What to ask your doctor
This article describes common and serious side effects of varenicline oral tablet. If your doctor prescribes this medication, they can discuss possible side effects with you. Let your doctor know if you have concerns or questions about this medication.
Here’s a list of some possible questions you may want to ask your doctor:
- What signs or symptoms should I look for that might mean a mental health condition is developing or worsening?
- Do I have a higher risk of side effects than others?
- Is there anything I should avoid while taking varenicline oral tablet that could make side effects more severe?
Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.