Allopurinol belongs to a class of medications called xanthine oxidase inhibitors. It works by reducing the production of uric acid in the body. High levels of uric acid may cause gout attacks or kidney stones. Allopurinol is used to treat gout (a type of arthritis in which uric acid, a naturally occurring substance in the body, builds up in the joints and causes sudden attacks of redness, swelling, pain, and heat in one or more joints). Allopurinol is used to prevent gout attacks, not to treat them once they occur. Allopurinol does not need to be stopped during an acute flare. Allopurinol is also used to treat high levels of uric acid that build up in the blood as tumours break down in people with certain types of cancer who are being treated with chemotherapy medications. It is also used to treat kidney stones that have come back in people who have high levels of uric acid in their urine.
ChEBI: Allopurinol is a bicyclic structure comprising a pyrazole ring fused to a hydroxy-substituted pyrimidine ring. It has a role as a radical scavenger, a gout suppressant, an antimetabolite and an EC 1.17.3.2 (xanthine oxidase) inhibitor. It is an organic heterobicyclic compound and a nucleobase analogue. It derives from a hydride of a 1H-pyrazolo[4,3-d]pyrimidine.
Allopurinol is commonly used for:
Treatment of gout
Treatment of elevated blood uric acid levels in cancer patients
Treatment of kidney stones caused by elevated blood uric acid level
Allopurinol works by reducing the production of uric acid in your body. If uric acid levels get too high, crystals can form in your joints and cause inflammation and pain (gout flares), or stones can form in your kidneys. By reducing the formation of uric acid, allopurinol helps prevent gout flares and kidney stones.
Allopurinol is very safe to use under most circumstances. Common side effects of allopurinol include abdominal pain, nausea, vomiting, diarrhea, headache or drowsiness etc. T An extremely small number of patients may have an allergic response to allopurinol. Allopurinol may cause severe skin rash, such as Hypersensitivity syndrome, Stevens-Johnson syndrome, and Toxic epidermal necrolysis. Such skin rash may involve ulceration of the oral cavity, throat, nose, genital area and the conjunctiva (red and swollen eye). It may develop and cause extensive blistering, redness, swelling, itchiness or skin shedding. It is common for these patients to experience flu-like symptoms like fever, chills, headache and muscle pain before severe skin rash develops. Some allergic reactions occur within minutes after drug administration, while others can take days or even months to develop. The risk of developing allergic reactions and the severity may differ for different patients, depending on the genetic variation, the culprit drug and medical histories. If skin rash appears, or if you experience the above reactions during the use of allopurinol, stop taking allopurinol and seek medical attention immediately.
