buspirone

Absorption: Rapidly absorbed.

Distribution: Widely distributed to tissues.

Protein Binding: 95%.

Metabolism/Excretion: Extensively metabolized by the liver via the CYP3A4 isoenzyme; 20–40% excreted in feces.

Half-Life: 2–3 hr.

Time/Action Profile ⬆ ⬇

(relief of anxiety)

ROUTE	ONSET	PEAK	DURATION
PO	7–10 days	3–4 wk	unknown

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Severe renal impairment;
Severe hepatic impairment;
Concurrent use of MAO inhibitors;
Lactation: Lactation.

Use Cautiously in:

Patients receiving other antianxiety agents (other agents should be slowly withdrawn to prevent withdrawal or rebound phenomenon);
Patients receiving other psychotropics;
OB: Safety not established in pregnancy;
Pedi: Children 6 yr (safety and effectiveness not established).

Adv. Reactions/Side Effects ⬆ ⬇

CV: chest pain, palpitations, tachycardia, hypertension, hypotension, syncope

Derm: rash, sweating, alopecia, blisters, bruising, dry skin, edema, flushing, pruritus

EENT: blurred vision, nasal congestion, sore throat, tinnitus, altered taste or smell, conjunctivitis

Endo: irregular menses

GI: nausea, abdominal pain, constipation, diarrhea, dry mouth, vomiting

GU: changes in libido, dysuria, urinary frequency, urinary hesitancy

MS: myalgia

Neuro: dizziness, drowsiness, excitement, fatigue, headache, incoordination, insomnia, nervousness, numbness, paresthesia, weakness, personality changes, tremor

Resp: chest congestion, hyperventilation, shortness of breath

Misc: clamminess, fever

Interactions ⬆ ⬇

Drug-drug:

Concurrent use with MAO inhibitors may ↑ risk of hypertensive reactions; concurrent use contraindicated; at least 14 days should elapse between discontinuation of MAO inhibitor and initiation of buspirone (or vice versa)
CYP3A4 inhibitors, including erythromycin, nefazodone, ketoconazole, itraconazole, andritonavir, may ↑ levels and risk of toxicity; ↓ dose to 2.5 mg twice daily with erythromycin; ↓ dose to 2.5 mg once daily with nefazodone.
CYP3A4 inducers, including rifampin, dexamethasone, phenytoin, phenobarbital, and carbamazepine, may ↓ levels and effectiveness.
Avoid concurrent use with alcohol.

Drug-Natural Products:

Concomitant use of kava-kava, valerian, or chamomile can ↑ CNS depression.

Grapefruit juice↑ levels and risk of toxicity; ingestion of large amounts of grapefruit juice is not recommended.

Route/Dosage ⬆ ⬇

PO (Adults ): 7.5 mg twice daily; may ↑ by 5 mg/day every 2–4 days as needed (not to exceed 60 mg/day). Usual dose is 10–15 mg twice daily.
PO (Children ≥6 yr): 5 mg once daily; may ↑ by 5 mg/day every 2–7 days as needed. Usual dose is 7.5–30 mg twice daily

Availability ⬆ ⬇

(Generic available)

Tablets: 5 mg; 7.5 mg; 10 mg; 15 mg; 30 mg

Assessment ⬆ ⬇

Assess degree and manifestations of anxiety before and periodically during therapy.
Buspirone does not appear to cause physical or psychological dependence or tolerance. However, patients with a history of substance use disorder should be assessed for tolerance or impaired control. Restrict amount of drug available to these patients.

Implementation ⬆ ⬇

Do not confuse buspirone with bupropion.
- Patients changing from other antianxiety agents should receive gradually decreasing doses. Buspirone will not prevent withdrawal symptoms.
PO: May be administered with food to minimize gastric irritation. Food slows but does not alter extent of absorption.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take buspirone exactly as directed. Take missed doses as soon as possible if not just before next dose; do not double doses. Do not take more than amount prescribed.
May cause dizziness or drowsiness. Caution patient to avoid driving or other activities requiring alertness until response to the medication is known.
Advise patient to avoid concurrent use of alcohol or other CNS depressants.
Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care professional before taking any Rx, OTC, or herbal products.
Instruct patient to notify health care professional if any chronic abnormal movements occur (dystonia, motor restlessness, involuntary movements of facial or cervical muscles).
Emphasize the importance of follow-up exams to determine effectiveness of medication.
Rep: Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.

Evaluation/Desired Outcomes ⬆ ⬇

Increase in sense of well-being.
- Decrease in subjective feelings of anxiety. Some improvement may be seen in 7–10 days. Optimal results take 3–4 wk of therapy. Buspirone is usually used for short-term therapy (3–4 wk). If prescribed for long-term therapy, efficacy should be periodically assessed.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇