Buspirone side effects and how to avoid them

In this article:

• Why was Buspar taken off the market?
• What are the side effects of buspirone?
• Does buspirone cause nightmares?
• How soon do buspirone side effects start?
• How long do side effects last?
• Long-term side effects
• Buspirone interactions that increase the risk of side effects
• Safety measures while using buspirone
• How to avoid buspirone side effects
• How to treat side effects

In this article

• Why was Buspar taken off the market?
• What are the side effects of buspirone?
• Does buspirone cause nightmares?
• How soon do buspirone side effects start?
• How long do side effects last?
• Long-term side effects
• Buspirone interactions that increase the risk of side effects
• Safety measures while using buspirone
• How to avoid buspirone side effects
• How to treat side effects

Buspirone is a generic prescription drug that treats symptoms of anxiety disorders. Buspirone used to be sold under the brand name Buspar, which is no longer sold in the U.S. Although buspirone was originally developed as an antipsychotic, it was determined to be ineffective for psychosis. However, it works well as an anxiolytic (an anti-anxiety medication). Even though buspirone lacks the side effects of other anti-anxiety drugs, such as benzodiazepines and antidepressants, it can cause certain side effects. 

Why was Buspar taken off the market?

Brand-name Buspar was taken off the market over a decade ago once generic buspirone became widely available. The Food and Drug Administration (FDA) found that Buspar did not cause any concerns for safety or effectiveness. 

What are the side effects of buspirone?

Compared to most other anxiolytics, buspirone has fewer side effects. 

Common side effects of buspirone

The most common side effects of buspirone are dizziness, drowsiness, nausea, headache, nervousness, and fatigue. Other side effects are reported in 3% or less of people who take buspirone. These side effects include:

• Insomnia
• Lightheadedness
• Dry mouth
• Excitement 
• Anger
• Confusion
• Blurred vision
• Diarrhea
• Increased heart rate, palpitations, and chest pain
• Muscle aches and pains
• Weakness
• Numbness
• Coordination problems
• Tremor
• Skin rash
• Sweating
• Tinnitus
• Sore throat and nasal congestion

Serious side effects of buspirone

Serious side effects caused by buspirone are rare but can include the following:

• Increased liver enzymes
• Akathisia (intense restlessness)
• Involuntary movements
• Hallucinations
• Serotonin syndrome
• Depression
• Seizures
• Suicidality
• Allergic reactions

Does buspirone cause sexual side effects?

In clinical trials, buspirone sexual side effects were rare. The most common (incidence rates of approximately 0.1% to 1%) were decreased or increased libido. Rare side effects (less than  0.01% incidence) included delayed ejaculation and impotence. For this reason, healthcare professionals use buspirone as an alternative to selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs). If you experience buspirone side effects sexually, contact your healthcare provider, who can rule out other causes. 

Anxiety medication coupons and resources

Does buspirone cause weight gain?

Weight gain is a rare side effect of buspirone, affecting only about 0.1% to 1% of people taking the drug. This number is so low that researchers aren’t certain whether the weight gain in these patients is actually caused by buspirone. Again, this makes buspirone preferable to other anxiety drugs, such as antidepressants and benzodiazepines, which can cause weight gain in some people.

RELATED: SSRI weight gain statistics

Does buspirone cause nightmares?

Dream disturbances can occur when taking buspirone, but buspirone nightmares are a rare side effect. Buspirone can increase rapid eye movement (REM) sleep and shift its occurrence to later in the sleep cycle. There have also been limited reports of sleepwalking when starting buspirone, but it is uncertain if there is a direct cause. It is unclear exactly how buspirone affects sleep.

How soon do buspirone side effects start?

Buspirone side effects may begin as early as the first week of taking it, since the body is not accustomed to the drug. Healthcare professionals believe that side effects may abate as doses are gradually adjusted to the best dose. 

Buspirone side effects during the first week

The most common side effects of buspirone start early in treatment and include dizziness, headache, nervousness, and nausea. In at least one study, most people taking buspirone rated their side effects as mild or moderate. 

How long do buspirone side effects last?

Healthcare professionals have not studied how long buspirone’s side effects last, but side effects typically subside as the body acclimates to the drug over the first few weeks of treatment. During clinical trials, at least 10% of participants dropped out due to side effects in the first three to four weeks. Most stopped taking buspirone because of problems like dizziness, headache, and nervousness. 

What are the long-term side effects of buspirone?

The long-term use of buspirone is not associated with a greater risk of potential side effects. Additionally, buspirone is not associated with any long-term adverse effects. However, there have been rare reports of people experiencing movement disorders, such as twitching, grimacing, writhing, intense restlessness, and Parkinson’s disease symptoms, as delayed side effects. 

Buspirone interactions that increase the risk of side effects

Although most people taking buspirone will be spared unpleasant side effects, drug interactions can increase the likelihood of developing minor or serious adverse reactions. 

Monoamine oxidase inhibitors

Because of the risk of high blood pressure and serotonin syndrome, buspirone should never be taken with monoamine oxidase inhibitors (MAOIs)—a small class of medications that includes the antidepressants Marplan (isocarboxazid), Nardil (phenelzine), Parnate (tranylcypromine), and Eldepryl (selegiline). It also includes the cancer drug procarbazine, the antibiotic linezolid, and methylene blue injections.

Serotonergic drugs

Buspirone increases serotonin levels in the brain. Serotonin is a neurotransmitter that passes signals between nerves. Serotonin syndrome, a potentially hazardous complication of drugs like buspirone, is more likely to occur when buspirone is combined with other drugs that raise serotonin levels (serotonergic drugs) or mimic serotonin (serotonin receptor agonists). These include the following medications: 

• Other anti-anxiety medications
• SSRIs 
• SNRIs
• Tricyclic antidepressants
• Antipsychotics
• Bipolar disorder medications, such as lithium
• Amphetamines
• Migraine drugs called triptans
• Seizure medications 
• Opioids
• Anti-nausea medications
• Parkinson’s disease medications
• Over-the-counter (OTC) dietary supplements, such as tryptophan and St. John’s wort

Other drugs can interfere with the body’s ability to break down buspirone. Some drugs slow the process down, increasing the risk of buspirone’s side effects. These include:

• Macrolide antibiotics, such as erythromycin
• Azole antifungals
• Some antiviral drugs
• Migraine drugs called ergots
• Grapefruit and grapefruit juice

Safety measures while using buspirone

Although buspirone is relatively safe, there are some safety measures to be aware of.

Who should never take buspirone?

Some people can’t take buspirone safely because of medical conditions or other drugs that they’re taking. These include:

• People who have had an allergic reaction to buspirone
• People taking MAOIs, serotonergic drugs, and drugs that interfere with the body’s ability to break down buspirone

Who should use caution when taking buspirone?

Kidney or liver problems can raise buspirone levels in the blood, increasing the risk of potential side effects. Healthcare providers may prescribe a low dose of buspirone to compensate for this.

Can you take buspirone when pregnant or breastfeeding?

Yes. Healthcare providers prescribe buspirone to pregnant women because there’s no evidence from human or animal studies that buspirone causes congenital disabilities or pregnancy problems. Still, you should tell your prescribing healthcare provider whether you are pregnant or plan to become pregnant while taking buspirone.  

Women who are breastfeeding may also be prescribed buspirone. The drug crosses into human breast milk, but there have been no reports of adverse effects in nursing infants. However, the FDA cautions nursing women and their doctors to consider alternatives. 

Does buspirone cause withdrawal symptoms?

Buspirone should not be suddenly stopped because of the risk of withdrawal side effects. While stopping it abruptly is not as dangerous as stopping a benzodiazepine, such as Xanax (alprazolam), it can still lead to unpleasant side effects, such as increased anxiety, dizziness, headache, irritability, nausea, nervousness, muscle cramps, trouble with sleeping, or fatigue. Talk to your health care provider before stopping buspirone or any other anti-anxiety medication. They can help you gradually reduce your dose safely with a buspirone taper schedule and avoid withdrawal side effects.

Like all drugs, it’s possible to overdose on buspirone. Symptoms of an overdose include nausea, vomiting, drowsiness, dizziness, digestive system problems, and constricted pupils. There are no reports of death caused by a buspirone overdose. However, a buspirone overdose should be considered a medical emergency. Call Poison Control at 800-222-1222 or call 911 if too much buspirone is taken. 

How to avoid buspirone side effects

Most people don’t experience side effects when taking buspirone. When side effects do occur, they usually fade over time. Even so, a few precautions can help minimize possible side effects:

1. Take buspirone as directed. Use an alarm or other reminder to take each dose at its scheduled time. If you miss a dose, take it as soon as you remember. If it’s nearly time to take the next dose, skip the missed dose and take the next dose as scheduled. Never take extra medicine for any reason.
2. Tell your healthcare provider about all of your medical conditions and medications. The best way to prevent adverse effects and interactions is to give your prescribing healthcare provider a complete medical history and list of all medications that you’re taking, including prescription drugs, OTC drugs, dietary supplements, and herbal products.
3. Be careful about driving and other risky activities. Although buspirone is not as strong of a sedative or muscle relaxant as other anti-anxiety medications, it can cause impairment. Avoid driving or working with heavy machinery until you know how the drug affects you.
4. Avoid grapefruit and grapefruit juice. Grapefruit has a chemical that slows down the body’s ability to metabolize buspirone. One study found that people drinking grapefruit juice while taking buspirone had a total drug exposure that was nine times the amount of drug exposure in people who didn’t drink grapefruit juice. That increased exposure to the drug comes with an increased risk of side effects.

How to treat the side effects of buspirone

Talk to your prescribing healthcare provider if you experience concerning side effects of buspirone, such as dizziness or other types of impairment. Lowering the dose may help, and you can avoid risky or complex activities, such as driving a car or operating machinery.

Serious side effects are rare and may require immediate medical help. These include seizures and allergic reactions, which typically accompany symptoms like facial swelling. 

If there are movement problems, such as involuntary grimacing, jerking, or others, immediately contact your prescribing healthcare provider.

Bottom line: Is buspirone safe?

Compared to other anti-anxiety drugs, buspirone is considered one of the safest treatment options for generalized anxiety disorder and anxiety symptoms. Buspirone does not cause many side effects, but when it does, they’re usually mild and temporary. There is no danger of drug dependence or addiction, and there’s no known fatality due to a buspirone overdose. Always inform your prescribing healthcare provider of any other medications or supplements you regularly take so that they can determine whether buspirone is safe for your specific condition.

Expert takeaway

“Buspirone can be a safer alternative to other anti-anxiety medications,” says Karen Berger, Pharm.D., member of the SingleCare Medical Board. “The right medication choice is different for everyone, so consulting with a healthcare provider can help determine the best treatment plan for you.”