Allopurinol (Oral)

Allopurinol is an effective drug for preventing acute gout and kidney stones. The treatment lowers the increased blood uric levels that occur during cancer


Allopurinol is a treatment for patients with gout and kidney stones. Patients who are undergoing cancer chemotherapy can also take allopurinol to reduce their high uric acid levels. The medication is a xanthine oxidase inhibitor that is taken by mouth or an injection. Allopurinol contains ingredients like lactose, cellulose, maize starch, and magnesium. The use of allopurinol takes an individualized treatment plan where every patient receives his/her prescription. For instance, the drug helps to manage patients who are receiving cancer treatment for diseases like lymphoma and leukemia.

The treatment should be withheld when uric acid ceases to be produced. Alternatively, allopurinol treats patients with symptoms of gout attacks, uric acid lithiasis, and tophi. Allopurinol helps to handle patients with recurrent calcium oxalate calculi who have uric acids levels of 750mg per day in male and 800mg per day in a female.

Kidney stones involve small particles of salt and minerals that accumulate in the kidney. A patient with this disease experiences pain in the abdomen, groin, and blood in urine. A patient can get kidney stones because of genes, family history, and dehydration. Allopurinol is the right medication for eliminating kidney stones and preventing further build-up of the particles. Patients can also drink plenty of water and maintain a healthy diet by reducing the intake of sodium diet and increasing the consumption of vitamin D and C.

On the other hand, gout attacks are caused by excessive uric acid in a patient's blood. The disease results in painful inflammation in the joints. They are formed by uric acid, a naturally occurring chemical, which builds up in the blood. As the level of uric acid increases, tiny grit-like crystals are accumulated in the tendons and joints. As a result, these crystals irritate the body tissues and lead to swelling and painful inflammations. Factors such as lifestyle choice, genetics, age, weight, gender, and medication contribute towards the formation of gout.

Allopurinol drug should be taken together with a painkiller to relieve pain because it does not react with gout. Patients who are unresponsive to the treatment of inflammatory bowel disease can use allopurinol to get better results. Allopurinol acts as an add-on medication for treating epilepsy because it hinders the secretion of glutamate from excitatory neurons. Patients who are undergoing chemotherapeutic treatment for tumor lysis syndrome can also take the drug since the procedure leads to the production of hyperuricemia. The medication is often prescribed by a qualified doctor or pharmacists.

Conditions treated

  • Kidney stones
  • Tumor lysis syndrome
  • Acute Gout

Type of medicine

  • A xanthine-oxidase inhibitor

Side effect

A patient should contact a doctor when he/she experiences the following symptoms:

  • Bleeding when urinating
  • Fever, headache with a serious blistering
  • Nausea, weight loss, jaundice, and stomach pain
  • Skin rash
  • Joint pain, numbness, and muscle weakness
  • Unusual bleeding from the mouth, rectum, and nose

Serious Side Effects

Patients should seek a doctor's intervention when they have dermatological side effects such as severe skin rash. In some incidences, patients with skin rash may show systemic symptoms like eosinophilia, jaundice, fever, chills, and leukopenia. Alternatively, some patients will experience skin reactions associated with arthralgia, exfoliation, and Less syndromes in rare scenarios.

Allopurinol also leads to gastrointestinal side effects including vomiting and diarrhea. The rare cases include gastritis and intermittent abdominal pain. Hypersensitivity is a rare side effect of allopurinol, for instance, lymphadenopathy exfoliation, and arthralgia. Some patients have problems related to cardiovascular systems such as vasodilation, pericarditis, and thrombophlebitis. Rare cases of infertility and gynecemastia in males were reported after using the treatment. Some patients showed side effects associated with the hemic and lymphatic system such as lymphocytosis, decreased prothrombin, and lymphadenopathy.

The other side effects of using allopurinol include malaise, infertility in men, nephritis, impotence, skin edema, and amnesia. Patients can experience insomnia, foot drop, decreased libido, facial edema, cataracts, and indigestion.


Allopurinol is taken daily to inhibit a gout attack from occurring. The treatment can be taken from two to three months to get better results. A patient's uric acid levels may increase shortly during the initial weeks of treatment, resulting in gout attacks. The patient should reach out to his/her doctor who will prescribe medications including anti-inflammatory drugs to take with allopurinol.

The doses of allopurinol depend on the type of disease, including gout. Patients with gout should take one tablet of allopurinol (100mg) per day during the initial phase. A patient with mild gout receives a dose of 200 to 300 mg per day. In the case of moderately severe gout, allopurinol dose is 400 to 600mg per day in divided doses. The standard dose for adults begins with 100 to 300mg/day. Late the dose is elevated to 200 to 600mg daily in divided doses. If the patient is a child with cancer, the dose is 10 to 20mg/kg of body weight daily. Additionally, patients with kidney problems or the elderly require a small dose of allopurinol.

A patient who has undergone cardiothoracic surgery takes a dose of 600mg a day before surgery and 600mg on the day of surgery. Further, the initial dose of hyperuricemia secondary to chemotherapy involves 600 to 800 mg per day orally for one to three days. Alternatively, patients can take allopurinol in the form of parenteral: 200 to 400 mg twice per day. A patient should take a forgotten dose if he/she has remembered immediately. However, the patients should skip the dose if the time for taking the subsequent dose is close.

Patients with congestive heart failure receive a dose of 300mg orally for a whole month to prevent the creation of superoxide free radicals and to increase the functionality of endothelial. Allopurinol is also administered by patients with leishmaniasis including cutaneous leishmaniasis: a low dose of 20mg/kg per day. Additionally, patients with mania take a dose of 300mg orally per day. The dose for patients with calcium oxalate calculi is 200-300mg daily during the starting phase. Later, the dose is increased to 300mg per day.

Patients with a risky percutaneous transluminal angioplasty are given a dose of 400mg after admission to the emergency room. Allopurinol is administered both orally and parenteral to patients with hyperuricemia. Patients who are less than 10 years old receive 200mg/m2 daily while patients over 10 years old receive a dose of 200 to 400mg/m2 per day. For allopurinol tablets, patients under six have a dose of 150mg daily. On the other hand, patients over six have a dose of 600 to 800 mg daily.

Dose Adjustments

Patients who are using allopurinol together with colchicine or anti-inflammatory medication should continue using the concomitant colchicine medications until the level of uric acid is normal. The concomitant can shift from a uricosuric agent by decreasing the dose while increasing the dose of allopurinol to maintain the normal uric acid level. Additionally, concomitant administration of allopurinol dose of 300 to 600 mg/day with azathioprine will necessitate the reduction of azathioprine to one-fourth of the normal dose. Patients with renal deficiency get a small dose because of their condition. Conversely, patients with liver problems are required to use allopurinol with caution. They should receive frequent liver function tests if they show signs such as pruritus and weight loss.

Patients should read the information leaflet of the manufacturer before taking the medication. The leaflet will provide vital information about the use, storage and side effects of allopurinol. They should also ensure that the symptoms of gout attacks have subsided completely before starting a new dose. Patients should follow their doctors' instructions concerning the dosage, for instance, the initial dose is one tablet per day.

Patients should take the drug with a lot of drinking water and after eating to prevent the risk of kidney stones. They should also follow the doctor's prescription and avoid overdosing when they have a missed a dose. Patients should visit their doctors regularly to determine their progress and the level of uric acid through blood tests. Additionally, patients with liver diseases should undergo liver function tests at the onset of the treatment.

Drug Interaction

Azathioprine: Concomitant use with allopurinol should be avoided because it results in bone suppression. Allopurinol inhibits the metabolic activities of azathioprine hence elevating plasma levels, which can lead to blood dyscrasias.

If the two medications should be used, then the normal dose of azathioprine should be decreased by a quarter and close monitoring of the patient's blood count simultaneously. Allopurinol hinders azathioprine from undertaking metabolism thus causing toxic effects on the body tissues and bone marrow.

Uricosuric agents: The combination of urate with allopurinol leads to a reduction in the secretion of oxypurines and an increased excretion of urinary uric acid.

Ampicillin/amoxicillin: Patients who have used amoxicillin with allopurinol have reported the increasing regularity of skin rashes.

Cyclophosphamide: Concomitant use of allopurinol with cyclophosphamide has led to reports of acute bone marrow suppression, particularly for patients with neoplastic anemia. Patients with lymphoma did not have an elevated toxicity in their bone marrow when treated with bleomycin, mechlorethamine, and cyclophosphamide.

Chlorpropamid: Allopurinol prolongs the lifecycle of Chlorpropamid since the two treatments compete for excretion in the renal tubule. When a patient has a renal impairment, the two treatments will cause hypoglycemia secondary.

Thiazide: When patients with lowered renal function take thiazide with allopurinol, they show signs of hypersensitivity including skin rash.

Tolbutamide: Allopurinol accelerates the conversion of inactive Tolbutamide into an active form.

The other drugs that will inhibit allopurinol:

  • Mercaptopurine
  • Chlorpropamide
  • A diuretic
  • Dicoumarol
  • Cyclosporine


Patients who are allergic to the ingredients of allopurinol should avoid taking the treatment when they show symptoms of allergic reactions or skin rashes. Skin rashes may be accompanied by hypersensitivity reactions such as purpuric lesions and exfoliate. The medicine should be stored out of the sight of children to prevent incidences of overdose.

Patients with a lowered renal function or a pre-existing illness like diabetes mellitus and hypertension, which can easily affect the renal system, require small doses of allopurinol and close monitoring during the initial phase of the treatment. Patients should seek a doctor's approval before taking the treatment, for instance, pregnant or lactating women. Patients who are using other treatments should also inform a doctor, for example, herbs or pharmaceutical drugs.

Patients should change their lifestyles to minimize the chances of gout attacks including eating healthy, avoiding alcohol and soft drinks as well as losing weight. They should also avoid sharing drugs with other people and consult the information leaflet of another person. Patients should avoid undertaking activities that require their full attention while taking the medication, including driving.

Allopurinol leads to liver problems that are reversible when the patient stops taking the medication. If a patient has a liver problem, he/she should tell the doctor at the onset phase of the treatment. The patient will also undergo regular blood tests while taking the medication. Patients should avoid taking allopurinol with treatments that cause toxicity in the bone marrow. This is because damage to the bone marrow reduces red blood cells and white blood cells synthesis, resulting in anemia and infections.

Patients receive gout attacks during the initial phase of treatment. The use of anti-inflammatories suppresses the pain of the gout attacks in the joints or tendons. The attacks decrease and become less serious as the patient continues to use the medicine. The gout attacks happen when the urates that change the serum uric acid become activated from the tissue deposits. Therefore, patients can take a maximum of two liters of water to produce more urine daily thus maintaining alkaline urine.

Patients with cancer should avoid taking the medication because of the high possibility of kidney failure. They should talk to a doctor before consuming alcoholic drinks because alcohol may reduce the efficacy of the medication. Patients should take the medication with lots of water to prevent the formation of xanthine calculi and renal precipitation of urates.

Patients should not compensate a missed dose on the subsequent schedule. For injections, they should administer a single-use IV infusion at six or eight hour intervals. This treatment does not treat patients with asymptomatic hyperuricemia since it is not part of an innocuous drug. Patients should monitor their levels of serum uric acid, renal function in patients with renal problems, and liver function during the initial stages.


Allopurinol should be kept safely and away from the reach of children. The reconstituted solution is stored at a temperature of 68 to 77 degrees Fahrenheit in a dry place. Patients should not use the medicine after its expiry date. Additionally, they should request the pharmacist to help them to dispose of the wasted medication properly.


Allopurinol is an effective medicine for alleviating the effects of gout and kidney stones. Gout attacks are associated with painful inflammations in the joints and tendons. Conversely, kidney stones have signs of pain in the abdomen and blood in urine. These diseases affect a patient's health and normal life. Allopurinol medication is administered orally or through an injection to adults, elderly and children in different doses. Patients can take the treatment with painkillers because allopurinol does not affect gout.

This treatment has several side effects such as jaundice, stomach pain, bleeding, and weight loss. Patients should seek medical attention when these symptoms do not subside. They should also read the leaflet information that comes with the medication before starting a dose. These leaflets contain information about the drug's side effects, storage options and how to use the medication.

Patients will experience gout attacks when they are commencing the treatment. They should contact a doctor to receive a prescription for an anti-inflammatory. Patients should take the right dose as prescribed by a doctor. They should contact a poison center if they overdose on the treatment. Patients should consume a lot of water when undergoing treatment to avoid build-up of kidney stones.

The normal dose of patients is one tablet, but the dose keeps increasing. Patients should understand that the treatment is administered depending on the patient's condition, for instance, mild gout and chronic gout. Children with cancer receive a small dose of allopurinol depending on their weight.

Allopurinol reacts in different ways with different medications. For instance, it can result in reduced metabolic activity and cause increased bone suppression. Patients should be cautious when using allopurinol with other treatments. Alternatively, concomitant use of allopurinol with amoxicillin leads to skin rash.

Patients should inform the doctor about their medical conditions before commencing treatment to safeguard against any potential allergic reactions. Patients should change their lifestyles to enhance the effectiveness of the medication. If they have a liver problem, they should inform the doctor to prescribe a dose based on their conditions.

Last Reviewed:
December 10, 2017
Last Updated:
April 04, 2018
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