Doxazosin Pharmacology


About Doxazosin
Alpha-1 adrenergic Antagonist, Quinazoline derivative, Antihypertensive.
Mechanism of Action of Doxazosin
The drug exerts its antihypertensive action by acting as a selective alpha-1 antagonist. It dilates both arteries and veins, thus it reduces total peripheral resistance, reduce blood pressure, & reduce venous return and cardiac output. The alpha-1 blockade in non vascular smooth muscles cause relaxation of smooth muscles of prostate, internal sphincter of the bladder etc. thus decrease the resistance to urinary outflow in patients with benign prostatic hypertrophy. It decrease the tone of prostatic and bladder neck muscles and relaxes bladder trigone, prostate, and prostatic urethra; reduces dynamic obstruction, increases urinary flow rate, causing more complete emptying of bladder. It also induces apoptosis in prostate smooth muscle cells The drug decreases LDL cholesterol & increases HDL cholesterol.
Pharmacokinets of Doxazosin
Absorption: It is well absorbed orally.
Distribution: Widely distributed in a highly plasma protein bound form.
Metabolism: It is metabolized in liver.
Excretion: Excreted mainly through bile and a small amount is excreted through faeces.

Onset of Action for Doxazosin
Duration of Action for Doxazosin
24 hours
Half Life of Doxazosin
18 hours
Side Effects of Doxazosin
1. Postural hypotension
2. Headache
3. Drowsiness
4. Dizziness
5. Dryness of mouth
6. Nasal congestion
7. Rash
8. Blurred vision
9. Palpitation
10. Weakness
11. Orthostatic hypotension
12. Fluid retention
13. Syncope
14. Impotence
15. Arthralgia
16. Myalgia

Contra-indications of Doxazosin
1. Hypersensitivity to the drug
Special Precautions while taking Doxazosin
1. Renal impairment
2. Hepatic impairment
3. Syncope
4. Started with low dose usually given at bed time
5. Prostate cancer

Pregnancy Related Information
Use with caution
Old Age Related Information
Use with caution
Breast Feeding Related Information
Children Related Information
Indications for Doxazosin
1. Hypertension
2. Benign prostatic hypertrophy

Interactions for Doxazosin
Clonidine: The anti-hypertensive effect of clonidine may be decreased.
Typical Dosage for Doxazosin
Hypertension: Starts with 1mg at bed time, then gradually increase at 1week intervals to 2mg, 4mg and 8mg respectively based on patient`s response.
Maximum daily dose: 16mg.
Benign prostatic hypertrophy: Starts with 1mg at bed time, then gradually increase at 1week intervals up to 8mg/day.

Schedule of Doxazosin
Storage Requirements for Doxazosin
Store at room temperature in a light resistant tightly closed container and keep out of reach of children

Effects of Missed Dosage of Doxazosin
Take the missed dose as soon as noticed and if it is the time to take the next dose then skip the missed dose.
Effects of Overdose of Doxazosin
Treatment is supportive and symptomatic. Keep the patient in supine position to maintain BP and heart rate. Give volume expanders for treating shock. Use vasopressors if required and monitor and support renal function.

Home Delivery for Doxazosin in Your City

Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including doxazosin.

However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for doxazosin and other medicines and health products. Home delivery services for doxazosin may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take doxazosin only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for doxazosin before they complete the sale. You can get this information while placing the order for doxazosin with the pharmacy.

Doxazosin is a generic medicine name and there are several brands available for it. Some of the brands for doxazosin might be better known than doxazosin itself. If the pharmacy that's willing to deliver medicines to your home doesn't have doxazosin in stock, you can ask for one of the branded alternatives for doxazosin.