BuSpar (buspirone) is a non-benzodiazepine anxiolytic (antianxiety and antipanic) primarily prescribed to teens and adults to relieve anxiety and associated symptoms. BuSpar was initially developed to be used as an antipsychotic, but it did not prove successful. Instead, it became attractive to clinicians as a non-sedating anxiolytic.
BuSpar is a central nervous system (CNS) selective drug that acts on a single subtype of serotonin (5-HT) receptor. It has high affinity for type 1 serotonergic receptors (5HT-1). The relative affinity is greater for the 5HT-1A receptor compared to that of 5HT-1B and acts as a partial or mixed agonist. This is what causes BuSpar’s anxiolytic activity.
This medication also has moderate affinity for dopamine receptors and may improve the quality of sleep for those experiencing anxiety without having hypnotic or sedative effects.
Although BuSpar is well-tolerated by many individuals, some of its adverse effects on various organ systems include:
CNS effects: Compared to other anxiolytics, central nervous system effects like psychomotor dysfunction and sedation occur less frequently with this medication. The most common adverse effects of BuSpar include dizziness, headache, and lightheadedness combined with drowsiness.
Gastrointestinal effects: Compared with placebos, nausea has been reported in some patients taking this medication. In some clinical studies individuals also experienced dry mouth, gastric distress, diarrhea, constipation, and vomiting.
Other effects: Urinary retention or increased frequency of urination, cramps, hyperventilation, dyspnea (shortness of breath), blurred vision, menstrual irregularities, galactorrhea, and thyroid abnormalities have be reported by some individuals, however, there is no formal relation between any of these side effects and BuSpar.
Additionally, although the sedative effects of this drug are less severe when compared to other anxiolytics, individuals must be cautioned about its use when performing activities requiring motor coordination (driving, operating machinery). Practice caution until you are sure you know how this drug will affect you.
Like many other anxiolytics, this medication has several interactions of which to be aware, including:
Monoamine oxidase inhibitors (MAOIs): The administration of tranylcypromine with this medication may increase blood pressure. It is not recommend to combine this drug with MAOIs.
Fluoxetine: During the concomitant administration of BuSpar with trazodone (a tricyclic antidepressant) for individuals experiencing panic attacks, generalized anxiety, and depression, the anxiety symptoms may increase if fluoxetine is added to the regime.
Haloperidol: Haloperidol’s concentration in serum increases when it is administered with this medication.
Aspirin: Aspirin can increase this medicaton’s serum concentration by displacing it from the plasma protein.
Erythromycin, Itraconazole and Nefazodone: These drugs inhibit the liver enzyme responsible for the metabolism of BuSpar. Dosage should be adjusted if combined with these medications.
Verapamil and Diltizem: Combining these drugs with BuSpar causes an increase in serum concentration.
Rifampin: Rifampin decreases the plasma concentration of this drug due to increased stimulation of liver metabolic activity.
Grapefruit juice: Grapefruit and products containing grapefruit should be avoided while taking this medication.
Food: Food may delay gastrointestinal absorption.
Alcohol: The effects of administering alcohol and this medication together are unpredictable. Alcohol should be avoided while using this medication.
This drug is not associated with any significant withdrawal symptoms. However, individual physiology may affect the manifestation of symptoms when discontinuing this medication. If you are concerned about withdrawal symptoms, or if you have been taking this drug for an extended period of time, you should consult with your doctor and make sure he or she does not recommend tapering off your dosage. Develop a safe plan to discontinue this medication with your health care provider.
Page content reviewed by James Pendleton, ND
Last Update: 04-28-2015