Doxazosin is a medication used to treat high blood pressure and symptoms of an enlarged prostate. The active ingredient is doxazosin mesylate. Alternative names for Doxazosin include Cardura and Carduran. It works by relaxing blood vessels and improving blood flow.
The cost of the Doxazosin varies from £0.27 to £1.33 per pills. It depends on the size of the pack and the amount of active ingredient (30 or 360 mg).
Doxazosin is prescribed for the treatment of hypertension and benign prostatic hyperplasia (BPH). It functions by relaxing blood vessels to improve blood flow and aids in reducing urinary retention symptoms.
Doxazosin is an alpha-1 adrenergic receptor antagonist. It works by blocking alpha-1 receptors on blood vessels, leading to their relaxation and dilation, which lowers blood pressure. In the case of BPH, it relaxes muscles in the prostate and bladder neck, making it easier to urinate.
Doxazosin is available in tablet and extended-release tablet forms. Immediate-release tablets are offered in strengths of 1 mg, 2 mg, 4 mg, and 8 mg. Extended-release tablets are available in 4 mg and 8 mg strengths.
The initial dose for treating hypertension is typically 1 mg once daily, with the possibility of gradual increases based on patient response. For BPH, the initial dose is also 1 mg daily, with increases as needed. Maximum dosages vary depending on the patient’s condition and response.
Doxazosin should be taken at the same time each day, with or without food. Extended-release tablets should not be crushed or chewed and should be swallowed whole. It is important to follow the prescribed dosing schedule for optimal therapeutic effects.
After oral administration, Doxazosin is well absorbed, with peak plasma concentrations occurring within 2 to 3 hours for immediate-release, and 8 to 9 hours for extended-release forms. It has a half-life of approximately 22 hours, allowing for once-daily dosing.
Doxazosin is extensively metabolized in the liver by the cytochrome P450 system, primarily CYP3A4. Metabolites are primarily excreted through bile and feces, with minimal renal excretion. Hepatic impairment can affect the drug’s metabolism and excretion.
Concurrent use with other antihypertensives, especially beta-blockers, can enhance hypotensive effects. Grapefruit juice may affect Doxazosin metabolism by inhibiting CYP3A4. Alcohol may increase drowsiness and dizziness.
Common side effects include dizziness, headache, fatigue, and edema. These are generally mild and often resolve on their own. Patients experiencing severe or persistent side effects should consult their healthcare provider.
Less common but serious side effects entail significant hypotension, especially after the initial dose, leading to fainting. Priapism, a prolonged and painful erection, although rare, requires emergency medical attention.
In elderly patients, dosage adjustments may be necessary due to increased sensitivity and coexisting health conditions. Pregnant women should use Doxazosin only if clearly needed, and it should not be used while breastfeeding, as it is not known if the drug passes into breast milk.
Doxazosin is contraindicated in patients with a known hypersensitivity to the drug or any of its components. Patients with a history of orthostatic hypotension should use caution when starting treatment.
Regular monitoring of blood pressure and pulse is recommended, particularly during initial dose titration. Periodic evaluation of liver function tests may be warranted in long-term therapy to detect potential hepatic issues early.
Store Doxazosin tablets at room temperature, away from moisture and heat. Keep the medication in its original container, tightly closed, and out of reach of children.
Unused Doxazosin should be disposed of following local regulations for medication disposal. Do not flush medications down the toilet or pour them into a drain unless instructed to do so.
Patients should be informed about the risk of dizziness, especially when rising from a sitting or lying position. They should be instructed to take the first dose at bedtime to minimize the risk of fainting. Usage of alcohol should be limited due to enhanced sedative effects.