Doxazosin

Clinical summary

Indications and usage Doxazosin tablets are an alpha 1 adrenergic antagonist indicated for: • Signs and symptoms of Benign Prostatic Hyperplasia (BPH) • Treatment of HypertensionTreatment of Hypertension Standard dosing • For the treatment of BPH: Initiate therapy at 1 mg once daily. Dose may be titrated at 1 to 2 week intervals, up to 8 mg once daily.( 2.2 ) • For the treatment hypertension: Initiate therapy at 1 mg once daily. Dose may be titrated as needed, up to 16 mg once daily. ( 2.3 ) Contraindications The use of doxazosin tablets is contraindicated in patients with a hypersensitivity to doxazosin, other quinazolines (e.g., prazosin, terazosin), or any of its components. Key warnings • Postural hypotension with or without syncope may occur. ( 5.1 ) • Risk of Intraoperative Floppy Iris Syndrome during cataract surgery. ( 5.2 ) • Screen for the presence of prostate cancer prior to treatment for BPH and at regular intervals afterwards. ( 5.3 ) Drug interactions • Strong cytochrome P450 (CYP) 3A inhibitors may increase exposure to doxazosin and increased risk of hypotension. ( 7.1 ) • Concomitant administration of doxazosin tablets with a phosphodiesterase-5 (PDE-5) inhibitor can result in additive blood pressure lowering effects and symptomatic hypotension. ( 7.2 )