Buspirone side effects and how to avoid them

Common buspirone side effects | Serious side effects | Side effects timeline | Interactions | Safety measures | How to avoid 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 United States. People take a buspirone oral tablet two or three times per day, depending on their prescriber’s instructions. 

Buspirone was originally developed as an antipsychotic. Although it was determined to be ineffective for psychosis, it works well as an anxiolytic. It lacks the side effects of other anti-anxiety drugs, such as benzodiazepines and antidepressants, which can slow brain, nerve, and muscle activity or cause sexual dysfunction. Additionally, it doesn’t cause physical dependence, addiction, withdrawal symptoms, or life-threatening problems when overdosed. For this reason, healthcare providers are confident about its safety. 

Common side effects of buspirone

Compared to most other anxiolytics, buspirone has fewer side effects. The most common side effects of buspirone are dizziness, nervousness, nausea, headache, and lightheadedness. Other side effects are reported in 2% or less of people who take buspirone. These side effects include:

• Excitement 
• Anger
• Confusion
• Blurred vision
• Diarrhea
• Muscle cramps, aches, and pains
• Weakness
• Numbness
• Tingling or other strange sensations 
• Coordination problems
• Tremor
• Skin rash
• Sweating
• Drowsiness

Serious side effects of buspirone

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

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

Sexual side effects of buspirone

In clinical trials, buspirone only rarely had sexual side effects. The most common (about 0.1% to 1% incidence) were decreased or increased libido. Rare side effects (less than  0.01% incidence) included delayed ejaculation and impotence. For this reason, mental health professionals and healthcare professionals use buspirone as an alternative to selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs).

Does buspirone cause weight gain?

Weight gain is a rare side effect of buspirone, affecting only about 1 in 100 to 1 in 1,000 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

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, nausea, and lightheadedness. In at least one study, most people taking buspirone rated their side effects as mild to 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 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), phenelzine, tranylcypromine, and 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?

Buspirone does not require dosage adjustments or extra monitoring unless people are taking medications that have drug interactions with buspirone. In buspirone’s drug information sheet, the Food and Drug Administration (FDA) does not specify any precautions for children, seniors, or patients with kidney disease or liver disease. However, kidney problems 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.

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

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. 

Buspirone does not cause withdrawal symptoms, so it can be safely stopped at any time. However, people who are switching to buspirone from another anti-anxiety medication may get withdrawal symptoms from the medication that they are stopping. In that case, the other drug will have to be stopped gradually with steadily decreasing doses in order to prevent withdrawal symptoms.

Like all drugs, it’s possible to overdose on buspirone. Symptoms of an overdose include nausea, vomiting, drowsiness, dizziness, digestive system problems, and narrowed 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 get immediate medical attention 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.

Take each dose as prescribed. Because buspirone tablets may be taken two to three times per day, 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 doctor about all medical conditions and medications.

The best way to prevent adverse effects is to give your prescribing healthcare professional a complete medical history and a list of all medications that you’re taking. That includes not only prescription drugs but also OTC drugs, dietary supplements, and herbal products.

3.  Do not take MAOIs with buspirone.

Make sure your prescribing healthcare provider knows if you are taking any MAO inhibitors. These have to be stopped at least 14 days before taking buspirone in order to prevent potentially serious side effects. 

4.  Take buspirone consistently, with or without food.

It doesn’t matter whether buspirone is taken with food or on an empty stomach. However, to get the maximum benefits from buspirone while minimizing possible side effects, take it the same way each time.

5.  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.

6.  Avoid drinking large amounts of 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. With that increased exposure to the drug comes an increased risk of side effects.

How to treat side effects of buspirone

Talk to your prescribing doctor if you experience side effects of buspirone. The most concerning side effects involve dizziness or other types of impairment. These can’t be treated, but 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, stop taking buspirone and 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 use does not cause many side effects, but when it does, they’re usually mild and temporary. Side effects, such as sedation, impairment, muscle relaxation, and sexual side effects commonly associated with anti-anxiety drugs, are less common with buspirone or not experienced at all. There is no danger of drug dependence or addiction, and buspirone is not associated with withdrawal symptoms. There’s no known fatality due to 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.