1. Antidepressants

Because buspirone increases serotonin, it can interact with other drugs that increase serotonin and could cause serotonin syndrome, a potentially life-threatening condition. This includes certain types of antidepressants, such as:

Generally, healthcare providers will try to avoid prescribing buspirone if you’re taking an antidepressant. If avoiding both is not possible, you’ll need to watch for signs of serotonin syndrome while taking both medications. This can include:

• Agitation
• Confusion
• Fast heart rate
• Flushed skin
• Tremors or muscle rigidity

Nefazodone (sold under the brand name Serzone) is another antidepressant that may interact with buspirone but in a different way. Nefazodone interferes with how the body processes buspirone, which increases the amount of the drug. This may cause side effects, such as light-headedness, weakness, drowsiness, and dizziness. If you’ve been prescribed nefazodone, your provider may advise taking a lower dose of buspirone.

2. Monoamine Oxidase Inhibitors (MAOIs)

MAOIs are a class of drugs used to treat depression, Parkinson’s disease, and other conditions. As older drugs, they are not as commonly prescribed as in the past due to their side effects and potential drug-to-drug interactions.

MAOIs should never be taken within 14 days of stopping buspirone, or vice versa. This means at least 14 days must pass between taking these drugs. The combination of an MAOI and buspirone can cause severely high blood pressure and/or serotonin syndrome. Examples of MAOIs include:

• Azilect (rasagiline)
• Nardil
• Zyvox, an antibiotic that is also classified as an MAOI

3. Other Drugs That Increase Serotonin

Along with antidepressants, other serotonin-boosting drugs can interact with buspirone and cause serotonin syndrome when taken together.

Examples of other drugs that increase serotonin include:

• Certain antipsychotics, such as Zyprexa (olanzapine) and Risperdal (risperidone)
• CNS stimulants, such as Adderall
• Opioid pain medicines, such as oxycodone
• Saint-John’s-wort (an herbal supplement)
• Triptans (medications that treat migraines), such as Imitrex

4. CNS Depressants

CNS depressants cause a slowing down of brain activity and are often used for their relaxing and sedating properties. However, they can interact with buspirone.

CNS depressants include alcohol, as well as certain medications, such as those to treat insomnia and anxiety. Alcohol should be avoided while taking buspirone.

Other examples of CNS depressants are:

• Benzodiazepines, such as Valium (diazepam) or Xanax (alprazolam)
• Medications used for sleep, such as Lunesta (eszopiclone) or Sonata
• Opioids, such as OxyContin (oxycodone) or hydrocodone

Taking a CNS depressant with buspirone can increase the risk of experiencing CNS depression, which includes symptoms like:

• Confusion
• Extreme drowsiness
• Low blood pressure
• Slowed breathing

In extreme cases, this can lead to unconsciousness or death.

5. Calcium Channel Blockers

Calcium channel blockers are commonly used to treat high blood pressure and other heart-related conditions.

Taking certain calcium channel blockers, notably Cardizem or Verelan, with buspirone can lead to increased levels of buspirone in the body. If taking both, watch for an increase in buspirone-related side effects.

6. Anti-Seizure Drugs

Certain antiepileptic drugs may interact with buspirone. These drugs are enzyme inducers, meaning they increase the metabolic activity of certain enzymes.

Enzyme inducers speed up the removal of certain drugs (such as buspirone) from the body. Doing so could make buspirone work less effectively. Therefore, when taking these drugs together, you might need a higher dose of buspirone to maintain its effectiveness.

Examples include:

• Dilantin
• Phenobarbital
• Tegretol

7. Antibiotics

Certain antibiotics, which are used to treat bacterial infections, can interact with buspirone in different ways.

Macrolide antibiotics, such as clarithromycin or erythromycin, can slow down the body’s processing of buspirone, leading to potentially increased and more serious side effects. Your healthcare provider may prescribe a lower dose of buspirone in this case.

On the other hand, rifampin (an antibiotic prescribed to treat tuberculosis and sold under the brand names Rifadin and Rimactane) can speed up the processing of buspirone in the body, possibly making buspirone less effective and requiring dose adjustments.

8. Antifungals

Antifungal medications are prescribed to treat certain types of yeast, or fungal, infections. Some antifungal medications can slow down the removal of buspirone from the body. This could lead to increased and more serious side effects of buspirone.

If the combination cannot be avoided, close monitoring and a lower buspirone dose may be required. Examples of antifungal drugs that can interact with buspirone are:

• Ketoconazole
• Noxafil (posaconazole)
• Sporanox
• Vfend (voriconazole)

9. Grapefruit

Grapefruit and grapefruit juice (including mixed juices that contain grapefruit as an ingredient) can slow the removal of buspirone from the body. This can lead to higher levels of the drug in the body and increased side effects. It’s recommended to avoid drinking large amounts of grapefruit juice while taking buspirone.

10. Ritonavir

Norvir (ritonavir) is a protease inhibitor used to treat human immunodeficiency virus (HIV) and also be found in combination drugs such as Kaletra (lopinavir/ritonavir) and the COVID-19 medicine Paxlovid (nirmatrelvir/ritonavir). Ritonavir can increase levels of buspirone in the body. You might need a dosage adjustment if both of these medications are prescribed.

11. Dexamethasone

Dexamethasone is a corticosteroid used to treat various inflammatory conditions. Dexamethasone can speed up the removal of buspirone from the body, possibly decreasing buspirone’s antianxiety effects. Taking these medications together may require dosage adjustments.

12. Haloperidol

Combining the antipsychotic haloperidol with buspirone could result in higher levels of haloperidol in the body. Side effects, such as increased drowsiness and heart rhythm problems, may occur. Close monitoring or dosage adjustments may be necessary if taking these medications at the same time.

Summary

Buspirone is a medication commonly used for anxiety. Many drugs may interact with buspirone in different ways. Some drugs or substances (such as MAOIs or alcohol) should be avoided while taking buspirone, while others may require close monitoring and a possible dosage adjustment.

The list above does not include every possible interaction that can happen. Before starting buspirone, tell your healthcare provider about all your medications, including prescription and over-the-counter drugs, vitamins, and supplements.