What is the maximum recommended dose of doxazosin for hypertension and benign prostatic hyperplasia (BPH)?

From the Guidelines

The maximum recommended dose of doxazosin for hypertension and benign prostatic hyperplasia (BPH) is 16 mg once daily. Doxazosin should be started at a low dose of 1 mg once daily, typically taken at bedtime, and gradually increased to minimize side effects like dizziness and orthostatic hypotension. For hypertension, dose adjustments can be made every 1-2 weeks based on blood pressure response, while for BPH, adjustments are typically made at 1-2 week intervals based on symptom improvement. Doxazosin works as an alpha-1 adrenergic receptor blocker, relaxing smooth muscle in blood vessels and the prostate, which lowers blood pressure and improves urinary flow in BPH. The medication can cause first-dose hypotension, so the initial dose should be taken at bedtime, and patients should be cautious when standing up quickly, especially when starting treatment or increasing the dose 1.

Some key points to consider when prescribing doxazosin include:

• Starting with a low dose and gradually increasing as needed to minimize side effects
• Monitoring blood pressure and urinary symptoms regularly to adjust the dose
• Being aware of the potential for first-dose hypotension and taking precautions to prevent it
• Considering the use of doxazosin in combination with other medications, such as 5 alpha-reductase inhibitors, for the treatment of BPH 1.

It's also important to note that doxazosin can cause orthostatic hypotension, especially in older adults, and patients should be cautioned to stand up slowly and carefully when starting treatment or increasing the dose 1.

From the FDA Drug Label

2.2 Benign Prostatic Hyperplasia ... The maximum recommended dose for BPH is 8 mg once daily. 2.3 Hypertension ... Daily dosage may be doubled up 16 mg once daily, as needed, to achieve the desired reduction in blood pressure. The maximum recommended dose of doxazosin is:

• 8 mg once daily for benign prostatic hyperplasia (BPH)
• 16 mg once daily for hypertension 2

From the Research

Maximum Recommended Dose of Doxazosin

The maximum recommended dose of doxazosin varies depending on the condition being treated.

• For hypertension, the maximum dose is typically 16 mg per day 3.
• For benign prostatic hyperplasia (BPH), the maximum dose is typically 8 mg per day 4, 5, 6.

Dose Titration

Dose titration is usually required when starting doxazosin therapy.

• The standard formulation of doxazosin requires a multiple-step titration regimen 3.
• The controlled-release gastrointestinal therapeutic system (GITS) formulation of doxazosin can be titrated through one step, making it more convenient to use 4.

Efficacy and Safety

Doxazosin has been shown to be effective and well-tolerated in the treatment of hypertension and BPH.

• Studies have demonstrated significant improvements in blood pressure and BPH symptoms with doxazosin therapy 3, 5, 7, 6.
• The most common adverse events associated with doxazosin are dizziness, headache, and fatigue 5, 7.