Allopurinol is a drug, that is used to treat hyperuricemia, which refers to the presence of excess uric acid in blood plasma. One of the most important complications associated with hyperuricemia is chronic gout, where uric acid crystals deposit in the joints, and cause joint inflammation and pain. This drug is primarily used to lower the production of uric acid in the body, and thus prevent the complications that can arise from the presence of excess uric acid in the body. Uses This drug is used to treat complications that can be caused by the presence of a high level of uric acid in the blood. This medication can prevent the formation of uric acid crystals in the body. It is basically used for treating certain types of kidney stones and gout. Sometimes, it is also used in lowering the level of uric acid in patients receiving cancer treatment. However, this medication can be prescribed by physicians for many other conditions, other than gout. Side Effects The side effects of this drug may not be experienced by all individuals. Only a small percentage of people can suffer from the side effects of this gout medication. The most commonly experienced side effects are, diarrhea, nausea, vomiting, and dizziness. Some other minor side effects of this medication are, indigestion, hair loss, stomach pain, headaches, and joint pain. If these side effects persist for a considerable period of time, then a physician should be consulted at the earliest. On the other hand, a skin rash is a serious side effect of this medicine. Some other serious side effects of this drug are, blood in urine and stool, black stool, fever, chills, a sore throat, painful or difficult urination, numbness or tingling in the hands or feet, muscle pain, mouth and lip sores, easy bruising and bleeding, jaundice or yellowing of the skin and the eyes, wheezing, and seizures. Sometimes, this drug can produce a severe allergic reaction in some individuals. An allergic reaction to this drug can manifest in itching, skin rash, hives, swelling of the face, lips, and the tongue, and breathing difficulty. On observing any of these symptoms, be sure to inform your physician as soon as possible. If taken with adequate care and in the appropriate dosage, this drug usually does not produce severe side effects. If you are already suffering from some medical conditions, like liver and kidney diseases, congestive heart failure, diabetes, and high blood pressure, then never take this drug without consulting your physician. Individuals who have earlier experienced an allergic reaction to any other medication, as well as pregnant and nursing women should talk to their physicians before taking this drug. Certain medications have been found to interact with allopurinol, and worsen or aggravate its side effects. Such medications include, amoxicillin, ampicillin, dicumarol, warfarin, chlorpropamide, etc. If you are taking any of these medications, inform your health care provider before taking allopurinol. Disclaimer: This article is for informative purposes only, and should not be treated as a substitute for professional medical advice.