The allopurinol , sold under the brand Zyloprim among others, is a drug used to lower high levels of uric acid in the blood. It is used specifically to prevent gout, prevent specific types of kidney stones, and the high uric acid levels that can occur with chemotherapy. It is taken by mouth or injected into a vein.
Index
Allopurinol – History
Allopurinol was first synthesized and reported in 1956 by Roland K. Robins (1926-1992), in a search for antineoplastic agents. Because allopurinol inhibits the breakdown (catabolism) of the drug thiopurine mercaptopurine, it was subsequently tested by Wayne Rundles, in collaboration with Gertrude Elion’s lab at Wellcome Research Laboratories to see if it could improve the treatment of acute lymphoblastic leukemia by enhancing the action. of mercaptopurine.
However, there were no improvements with leukemia, so work turned to other compounds, and the team then began testing allopurinol as a potential for gout. Allopurinol was first marketed as a gout treatment in 1966.
Allopurinol was approved for medical use in the United States in 1966. It is on the World Health Organization’s Essential Drug List, the safest and most effective drugs needed in a healthcare system. Allopurinol is available as a generic drug. In the United States, a month of treatment costs less than $ 25.
Allopurinol – Usos
Allopurinol is used to treat gout and certain types of kidney stones. These patients may have an increase in uric acid levels due to the release of uric acid from dying cancer cells. Allopurinol works by reducing the amount of uric acid that the body makes. Increased uric acid levels can cause gout and kidney problems.
How to use Allopurinol
Take this medication by mouth, usually once a day or as directed by your doctor. Take this medicine after a meal to reduce stomach upset. If your dose is more than 300 milligrams per day, you will need to take several smaller doses throughout the day to get this amount (see your doctor for instructions).
It is best to drink a full glass of water with each dose and at least 8 more glasses (8 ounces each) of liquid a day. Your doctor can also tell you how to lower the acid in your urine (for example, avoid large amounts of ascorbic acid / vitamin C).
The dose is based on your medical condition and response to treatment. Use this medicine regularly to get the most benefit from it. To help you remember, take it at the same time (s) every day.
For the treatment of gout, it may take up to several weeks for this medicine to have an effect. You may have more gout attacks for several months after starting this drug while your body removes excess uric acid. Allopurinol is not a pain reliever.
Allopurinol – Side Effects
Common side effects when used orally include itching and a rash. Common side effects when used by injection include vomiting and kidney problems. Although historically not recommended, starting allopurinol during a gout attack appears to be safe. In those already taking the drug, it should be continued even during an acute gout attack. While use during pregnancy does not appear to be harmful, this use has not been well studied. Allopurinol belongs to the xanthine oxidase inhibitor family of drugs.
May cause stomach upset, nausea, diarrhea, or drowsiness. Remember that your doctor has prescribed this medicine for you because he or she has determined that the benefit to you outweighs the risk of side effects. Many people using this medicine do not have serious side effects.
Be careful and watch out for side effects such as arm / leg numbness / tingling, easy bleeding / bruising, signs of infection (such as fever, persistent sore throat), unusual tiredness, signs of kidney problems (such as change in amount of urine, painful / bloody urination), yellowish eyes / skin, severe stomach / abdominal pain, persistent nausea / vomiting, dark urine, unusual weight loss, eye pain, vision changes.
This drug can commonly cause a rash that is usually not serious. However, you may not be able to tell it apart from a rare rash that could be a sign of a serious reaction. Get medical help right away if you develop a rash.
A very serious (possibly fatal) allergic reaction to this drug is rare. Be careful in case of skin rash, itching / swelling (especially of the face / tongue / throat), severe dizziness, shortness of breath.
Allopurinol – Precautions
Before taking allopurinol, tell your doctor or pharmacist if you are allergic to it; or if you have had a severe reaction to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Consult your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver disease, kidney disease, diabetes, high blood pressure (hypertension), unusual diets (such as fasting).
This medicine may make you drowsy. Alcohol can also decrease the effectiveness of this drug. Limit alcoholic beverages. Talk to your doctor if you are using marijuana.
Kidney function declines as you age. this medicine is eliminated through the kidneys. Therefore, older adults may be at higher risk for side effects while using this drug.
During pregnancy, this drug should be used only when clearly needed. Consult your doctor before breastfeeding.
Allopurinol – Contraindications
Allopurinol should not be given to people who are allergic to it. Drug interactions are extensive and include the following:
Azathioprine and 6-mercaptopurine: Azathioprine is metabolized to 6-mercaptopurine, which in turn is inactivated by the action of xanthine oxidase, the target of allopurinol. Administering allopurinol with any of these medications in its normal dose will lead to an overdose of any of the medications; only a quarter of the usual dose of 6-mercaptopurine or azathioprine should be administered;
Didanosine: plasma didanosine Cmax and AUC values approximately doubled with concomitant allopurinol treatment; it should not be administered concomitantly with allopuroinol. Allopurinol may also increase the activity or half-life of the following medications, in order of seriousness and certainty of interaction:
- Ciclosporin
- Coumarin blood thinners, such as warfarin (rarely reported, but serious when it occurs)
- Vidarabine
- Clorpropamida
- Phenytoin
- Theophylline
- Cyclophosphamide, doxorubicin, bleomycin, procarbazine, mechlorethamine
Allopurinol – Interactions
Some products that may interact with this drug are: “blood thinners” (eg, warfarin), didanosine.
Allopurinol – Pharmacology
A common misconception is that allopurinol is metabolized by its target, xanthine oxidase, but this action is carried out primarily by aldehyde oxidase. The active metabolite of allopurinol is oxipurinol, which is also a xanthine oxidase inhibitor. Allopurinol is almost completely metabolized to oxipurinol within two hours of oral administration, whereas oxipurinol is slowly excreted by the kidneys over 18-30 hours. For this reason, oxipurinol is believed to be responsible for most of the effect of allopurinol.
Dr. Samantha Robson ( CRN: 0510146-5) is a nutritionist and website content reviewer related to her area of expertise. With a postgraduate degree in Nutrition from The University of Arizona, she is a specialist in Sports Nutrition from Oxford University and is also a member of the International Society of Sports Nutrition.
