What dose of buspirone should be initiated in a patient with inadequate anxiety control on hydroxyzine (hydroxyzine) 25mg three times a day?

From the Guidelines

For a patient with inadequate anxiety control on hydroxyzine 25mg three times daily, buspirone should be initiated at 5mg twice daily, with a maximum dose of 20mg three times daily, as this dosing regimen is recommended for patients with mild to moderate agitation and may take 2 to 4 weeks to become effective 1. When considering the switch from hydroxyzine to buspirone, it's essential to note that buspirone has a different mechanism of action, acting as a partial agonist at serotonin 5-HT1A receptors, which makes it effective for generalized anxiety disorder without causing sedation or dependence. Some key points to consider when initiating buspirone include:

• Starting with a low dose of 5mg twice daily and gradually increasing as needed and tolerated
• The maximum recommended dose is 20mg three times daily, as indicated in the guidelines for anxiolytic drugs 1
• Buspirone may take 2 to 4 weeks to reach its full therapeutic effect, so it's crucial to continue the hydroxyzine initially and gradually taper it off as the buspirone takes effect
• Common side effects of buspirone include dizziness, headache, and nausea, which are typically mild and transient
• Taking buspirone with food can help reduce gastrointestinal side effects Unlike benzodiazepines, buspirone is not associated with dependence or withdrawal and doesn't impair cognition or motor function, making it a safer alternative for long-term use.

From the FDA Drug Label

The recommended initial dose is 15 mg daily (7.5 mg b.i.d.) To achieve an optimal therapeutic response, at intervals of 2 to 3 days the dosage may be increased 5 mg per day, as needed.

The initial dose of buspirone to be initiated in a patient with inadequate anxiety control on hydroxyzine should be 15 mg daily (7.5 mg b.i.d.) 2.

• The dose may be increased by 5 mg per day at intervals of 2 to 3 days as needed to achieve an optimal therapeutic response.
• The maximum daily dosage should not exceed 60 mg per day.

From the Research

Dose of Buspirone for Inadequate Anxiety Control on Hydroxyzine

• The patient is currently taking hydroxyzine 25mg three times a day for anxiety, but it's not working effectively.
• To determine the appropriate dose of buspirone, we can look at studies that compared hydroxyzine and buspirone in patients with generalized anxiety disorder.
• A study from 1998 3 compared the efficacy of hydroxyzine, buspirone, and placebo in patients with generalized anxiety disorder. The study found that hydroxyzine was more effective than placebo, and buspirone was also effective in reducing anxiety symptoms.
• The buspirone dose used in this study was 5mg morning and mid-day, and 10mg evening, which is a total daily dose of 20mg.
• Another study from 1990 4 found that most patients were successfully managed on daily doses of buspirone ranging from 15 to 30 mg/day.
• A meta-analysis from 1999 5 compared the safety and tolerability of two dose regimens of buspirone, 15mg twice daily and 10mg three times daily, and found that both regimens were well-tolerated and effective.

Recommended Buspirone Dose

• Based on these studies, a reasonable dose of buspirone to initiate in a patient with inadequate anxiety control on hydroxyzine 25mg three times a day could be 15-20mg per day, divided into two or three doses.
• However, the optimal dose of buspirone may vary depending on individual patient factors, such as the severity of anxiety symptoms and the presence of other medical conditions.
• It's also important to note that buspirone may take several weeks to reach its full therapeutic effect, so patients should be monitored closely and the dose adjusted as needed 6.