Allopurinol: Uses, Dosage, Side Effects, and Precautions

Allopurinol, marketed under brand names such as Zyloprim, is a medication used to lower elevated blood uric acid levels. It is commonly used to prevent gout, certain types of kidney stones, and elevated uric acid levels that may occur as a result of chemotherapy. Allopurinol can be taken orally or inserted into a vein.

What are the Uses of Allopurinol Tablet?

Conditions Allopurinol is Used to Treat

• Gout: Treatment and prevention of gout.
• Kidney Stones: Prevention of certain types of kidney stones.
• Tumour lysis syndrome (manages uric acid during cancer treatment)
• Hyperuricemia in patients undergoing chemotherapy
• Chemotherapy: Prevention of increased uric acid levels due to the release of uric acid from dying cancer cells during chemotherapy.

What Are the Secondary Benefits of Allopurinol?

Some secondary or off-label uses include:

• Preventing uric acid-related complications in people with high cell turnover (e.g., during leukemia treatment)
• Managing recurrent calcium kidney stones
• Used alongside certain cancer therapies to reduce uric acid buildup
• Emerging research suggests that allopurinol lowers blood pressure in some patients, particularly those with high uric acid levels and early-stage hypertension.

How to Use Allopurinol?

• Dosage: Take orally once a day or as instructed by your doctor.
• Stomach Upset: Take after a meal to relieve stomach upset.
• Large Dosages: If the daily dosage is more than 300 mg, it'should be taken in smaller doses throughout the day (consult your doctor).
• Hydration: Drink a full glass of water with each dose and at least 8 additional glasses (8 ounces each) of fluid daily.
• Acid Reduction: Your doctor may advise how to reduce acid in your urine.
• Consistency: Take at the same time every day to help you remember.
• Effectiveness: It may take several weeks to see the effects in treating gout. Continue to take prescribed gout medications for pain relief.

How Allopurinol Works?

Allopurinol does not directly interact with hormones or the nervous system. Its action is focused on metabolism and enzyme inhibition:

• It blocks the enzyme xanthine oxidase, which helps convert purines into uric acid.
• Reduces the amount of uric acid produced by the body.
• Helps prevent uric acid buildup, which can lead to issues with the gut and kidneys.

It works at the metabolic level and has no known direct effect on hormone regulation or nervous system function.

Dosage of Allopurinol

What Should I Do If I Miss a Dose?

• If you forgot to take any dose, take it as soon as you recall it.
• If it is near the time of the next dose, skip the forgotten dose.
• Take your next dosage at regular intervals of time.
• Do not double the dose.

What happens if an Overdose?

If you or someone has taken too much of this medicine and has serious symptoms such as passing out or trouble breathing, seek emergency medical help immediately.

Symptoms of Overdose can include

• Severe Drowsiness
• Fainting
• Seizures
• Fast Heartbeat.

What are the Side Effects of Allopurinol?

Common Side Effects

• Rash
• Nausea
• Vomiting
• Joint pain
• Dizziness
• Itching
• Sore throat

Severe Side Effects

• Renal failure
• Blood disorders
• Difficulty breathing
• Cardiovascular abnormalities
• Cataracts
• Confusion
• Bruise
• Nosebleed
• Foot drop
• Blood in urine
• Liver damage
• Decreased muscle tone
• Inflammation of the iris in the eye
• Kidney function abnormality
• Severe vision impairment
• Inflammation of the nerves

Precautions and Warnings While Taking Allopurinol

• Allergies: Inform your doctor if you are allergic to allopurinol or have had any reactions to it or other medications.
• Medical Conditions: Notify your doctor if you have liver disease, kidney disease, diabetes, high blood pressure, or irregular diets.
• Drowsiness: Allopurinol can cause drowsiness. Avoid driving or operating machinery until you know how it affects you.
• Alcohol: Alcohol can increase drowsiness and reduce the effectiveness of the medication. Limit alcohol consumption.
• Elderly: Older adults may be more susceptible to side effects due to decreased kidney function.
• Pregnancy: Use only if urgently needed. Consult your doctor.
• Breastfeeding: Allopurinol is present in breast milk. Consult your doctor before breastfeeding.

Possible Drug Interactions and with Other Medications

• Drug interactions can cause your medications to function differently or increase the risk of severe side effects.
• Keep a list of all the medicines you use (including prescription and medications, as well as herbal remedies) and share it with your doctor and pharmacist.
• Do not begin, stop, or alter the dosage of any medications without your doctor's permission.
• Blood thinners (warfarin), capecitabine, and didanosine are some of the products that may interfere with this drug.

Notes

• Do not share this medication with anyone else, even if they have the same symptoms.
• Lab and medical tests such as blood pressure and liver function should be done while you are taking this medication. Consult your doctor for more details and information.

How Should Allopurinol Be Stored?

• Store at room temperature away from direct sunlight, heat, and moisture.
• Keep the medicine in its original packaging to protect it from light and moisture.
• Avoid storing it in bathrooms or places with high humidity.

What Happens If Allopurinol Is Not Stored Properly?

• Improper storage may reduce its effectiveness or cause the tablets to break down.
• Exposure to heat, moisture, or sunlight can lead to loss of potency or contamination.

Additional Storage Tips

• Keep all medications away from small children.
• Do not freeze the medicine.
• Do not store it in the bathroom.
• Never flush medications down the toilet or pour them into a drain unless instructed to do so.
• Properly discard this product when it gets expired or is no longer in use. Consult your pharmacist or local waste disposal company.

Allopurinol vs Colchicine

References

IEffect of Allopurinol in Chronic Kidney Disease Progression and Cardiovascular Risk