Allopurinol Pharmacology


About Allopurinol
Xanthine oxidase inhibitor, In hyperuricemia in gout or during cancer chemotherapy.
Mechanism of Action of Allopurinol
It inhibits an enzyme xanthine oxidase that is necessary to form uric acid (the enzyme catalyzing the conversion of hypoxanthine to xanthine, and xanthine to uric acid), a substance present in abnormally large amounts in the blood of persons with gout that forms solid deposits in the joints, the kidneys, and other tissues
Pharmacokinets of Allopurinol
Absorption- Well absorbed after oral administration
Distribution- Widely distributed in the body. Drug and its metabolites not bound to the plasma proteins
Metabolism- It is metabolized in the liver by the enzyme xanthine oxidase. Oxypurinol is its active metabolite
Excretion- Excreted via urine and feces (as unchanged and metabolites form)
Onset of Action for Allopurinol
2 to 3 days
Duration of Action for Allopurinol
30 hrs
Half Life of Allopurinol
Its plasma half life is 15 hrs
Side Effects of Allopurinol
1. Upset stomach.
2. Diarrhea.
3. Drowsiness.
4. Skin rash.
5. Painful urination.
6. Blood in the urine.
7. Irritation of the eyes.
8. Swelling of the lips or mouth.
9. Fever
10. Sore throat.
11. Chills.
12. Loss of appetite.
13. Unexpected weight loss.
14. Itching.
Contra-indications of Allopurinol
1. Hypersensitivity to the drug.
2. Acute gout.
3. Hemochromatosis.
Special Precautions while taking Allopurinol
1. Hepatic impairment.
2. Renal dysfunction.
3. Any work which require mental alertness such as driving and operating machine.
Pregnancy Related Information
Use with caution.
Old Age Related Information
Use with caution.
Breast Feeding Related Information
Children Related Information
Use with caution.
Indications for Allopurinol
1. Primary hyperuricaemia of Gout.
2. Secondary hyperuricaemia due to myeloid metaplasia, radiation, cancer chemotherapy, thiazide diuretics.
3. Prevention of uric acid nephropathy.
Interactions for Allopurinol
ACE Inhibitors: Higher risk of hypersensitivity reactions.
Oral hypoglycemic Agents: Enhanced activity.
Anticoagulants: Enhanced activity.
Thiopurines (Azothioprine & Mercaptopurine): Clinically significant increase in pharmacologic and toxic effects.
Uricosuric Agents (Probenecid): Enhance urinary excretion of Allopurinol.
Cyclophosphamide: Myelosuppressive effect of cyclophosphamide enhanced.
Thiazide Derivatives: Increase in hypersensitivity reactions to Allopurinol.
Ampicillin: Increase in ampicillin induced skin rash.
Salicylates: Enhance urinary excretion of allopurinol.
Typical Dosage for Allopurinol
Initial dose: 100 - 200 mg daily
Maintenance dose: 200-800 mg daily
Schedule of Allopurinol
Storage Requirements for Allopurinol
Store at 15-25?C (59-77?F) in a dry place and protect from light
Effects of Missed Dosage of Allopurinol
Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose.
Effects of Overdose of Allopurinol
Give symptomatic and supportive treatment.

Home Delivery for Allopurinol in Your City

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

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 allopurinol and other medicines and health products. Home delivery services for allopurinol 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 allopurinol 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 allopurinol before they complete the sale. You can get this information while placing the order for allopurinol with the pharmacy.

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