1 What is Zyloprim?

Brand: Zyloprim

Generic: Allopurinol

Zyloprim is used to prevent or treat high uric acid levels in the blood. Gout or gouty arthritis (inflammation and pain in a joint) is caused by high uric acid levels. 

Zyloprim is a xanthine oxidase inhibitor that causes less uric acid to be produced by the body. Zyloprim is also used to prevent or treat high uric acid levels that may be caused by cancer medications or for patients with kidney stones that contain calcium.

This medication is only available with your doctor’s prescription. This medication is available in the following forms:

  • Capsule
  • Tablet

2 What to Know Before Using

Before using Zyloprim, you must know all about the risks and complications associated with it. This is a decision that you and your doctor will make together.

For this medication, there are many things that need to be considered:

Allergies: Inform your doctor if you have ever had an allergic reaction to doxorubicin or to any other medications. It is also important to inform your doctor of any non-medicine allergies such as foods, dyes, preservatives or animals. 

Pediatric: Up-to-date Pediatric Appropriate studies have not indicated any problems that would limit the use of this medication.

Geriatric: No appropriate studies have been performed on the relationship of age to the effects of this medication in children. Safety and efficacy have not been established.

Pregnancy: This medication is listed as Pregnancy Category C. This means that animal studies have shown an adverse effect and no studies have been performed on pregnant women OR there are no adequate studies on pregnant animals and pregnant women.

Breastfeeding: Studies in women suggest that this medication poses minimal risk to the infant when used while breastfeeding.

Drug Interactions: Certain medications should not be used together. However, in certain cases, two medications may be used together, even if an interaction might occur. In these cases, your doctor may want to change your dose or take other precautions.

When taking this medication, it is important that you inform your doctor if you are taking any of the medications listed below. The following interactions were selected on the basis of potential significance and are not all-inclusive. Using this medication with any of the following is not recommended.

Your doctor may decide not to treat you with this medication, or change some of the other medications you take:

  • Didanosine

Using this medication with any of the following medication is not recommended, but may be unavoidable in some cases.

Your doctor may make the decision not to treat you with this medication or change some of the other medications you take:

  • Azathioprine
  • Captopril
  • Cyclophosphamide
  • Enalapril
  • Enalaprilat
  • Mercaptopurine
  • Pegloticase
  • Tegafur

Using this medication with any of the following medications may increase your risk of side effects. However, using both medications may be the best treatment for you.

If both medications are prescribed together, your doctor may change the dose or how often you take one or both medications:

  • Aluminum Hydroxide
  • Cyclosporine
  • Phenprocoumon
  • Vidarabine
  • Warfarin

Other Interactions: Certain medications should not be used while eating, or while eating certain foods in case of negative interactions. Using alcohol or tobacco with certain medications may also cause negative interactions. Talk with your doctor about the use of your medication with food, alcohol or tobacco.

Other Medical Problems: Pre-existing medical problems may affect the use of this medication.

Be sure to tell your doctor if you have any other medical problems, especially: 

  • Bone marrow problems
  • Liver disease - Use with caution. May make these conditions worse
  • Kidney disease - Use with caution. The effects may be increased because of slower removal of the medication from the body.

3 Proper Usage

Proper usage of Zyloprim requires strict adherence to your doctor’s orders. Do not take more, less or for a longer or shorter period of time than your doctor tells you.

Take this medication after meals to avoid an upset stomach. Take this medication with plenty of liquids to help prevent kidney stones. Check with your doctor about the amount of liquid you or your child should drink each day.

Dosing: Different patients will be given a different dose of this medication based on the strength of the medication. The number of doses you take each day, the time between doses and the length of time you take this medication depends on the reason you are taking this medication.

The following information only includes the average dose of this medication. If your dose is different, do not change it without first speaking to your doctor.


  • For treatment of gout:
    • Adults - Start with 100-300mg per day, taken once a day or in divided doses. Your doctor may adjust the dose as needed
    • Children - Use and dose must be determined by your doctor
  • For treatment of high uric acid levels caused by cancer medications:
    • Adults, teenagers and children 11 years of age and older - 600-800mg per day, taken in divided doses for 2-3 days
    • Children 6-10 years of age - 300mg per day, taken once a day for 2-3 days
    • Children younger than 6 years of age - 150mg per day, taken once a day for 2-3 days
  • For treatment of kidney stones:
    • Adults - 200-300mg per day, taken once a day or in divided doses. Your doctor may adjust your dose as needed. The dose is not normally more than 800mg per day
    • Children - Use and dose must be determined by your doctor

Missed dose: If you miss a dose of this medication, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and resume your normal dosing schedule. Do not double dose.

Storage: Store this medication in a closed container at room temperature. Keep it away from heat, moisture, and direct light. Do not freeze.

Keep our of the reach of children. Do not keep expired medication or medication you no longer need. Ask your doctor how to dispose of any medication you do not use.

4 Precautions to Take

Before using Zyloprim, there are some precautions you must take. It is very important that your doctor checks in with you often while you are receiving this medication to make sure that it is working properly

Do not take other prescription or over-the-counter medications without asking your doctor. When starting this medication, you may have more gout attacks. Continue using this medication even if this occurs. Your doctor may give you other medications to help prevent these attacks.

Stop taking this medication and inform your doctor immediately if you develop a skin rash, hives, swelling of the lips or mouth or any allergic reaction to this medication.

Inform your doctor immediately if you have pain or tenderness in the upper stomach, pale stool, dark urine, loss of appetite, nausea, unusual fatigue or weakness or yellow eyes or skin (jaundice). These could be signs of a serious liver problem.

This medication may cause some people to become drowsy or less alert than normal. This is more likely to happen when you begin taking this medication, or when you increase the dosage. 

Make sure you know how you react to this medication before driving, using machinery or doing anything else that could be dangerous if you are not alert.

5 Potential Side Effects

As with many medications, there are several potential side effects associated with Zyloprim. Although not all of these side-effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if you experience any of the following side-effects:

More common:

  • Ankle, knee or big toe joint pain
  • Joint stiffness or swelling
  • Rash
  • Rash with flat lesions or small raised lesions on the skin


  • Abdominal or stomach pain
  • Agitation
  • Ammonia-like breath odor
  • Anxiety
  • Bleeding gums
  • Blistering, peeling or loosening of the skin
  • Blood in the urine or stools
  • Bloody nose
  • Bloody or black, tarry stools
  • Blue or pale skin
  • Bruising
  • Changes in skin color
  • Chest pain or discomfort
  • Chest pain, possibly moving to the left arm, neck, or shoulder
  • Chills
  • Clay-colored stools
  • Cloudy urine
  • Coma
  • Confusion
  • Constipation
  • A cough or hoarseness
  • Coughing up blood
  • Cracks in the skin
  • Dark urine
  • Decreased urine output
  • Depression
  • Diarrhea
  • Difficulty breathing
  • Dizziness
  • Drowsiness
  • Dry mouth
  • Feeling faint, dizzy, or lightheaded
  • Feeling of warmth or heat
  • Fever
  • Fever with or without chills
  • Flushing or redness of the skin, especially on the face and neck
  • General feeling of discomfort or illness (malaise)
  • Headache
  • Hostility
  • Incoherent speech
  • Increased urination
  • Irritability
  • Itching
  • Joint or muscle pain
  • Large, flat, blue or purplish patches in the skin
  • Lethargy
  • Light-colored stools
  • Loss of appetite
  • Loss of heat from the body
  • Lower back or side pain
  • Metallic taste
  • Muscle twitching
  • Muscle weakness
  • Nausea or vomiting
  • Pain, tenderness, or swelling of the foot or leg
  • Painful or difficult urination
  • Pinpoint red or purple spots on the skin
  • Rapid weight gain
  • Rash
  • Red, irritated eyes
  • Red, swollen skin
  • Redness, soreness, or itching skin
  • Right upper abdominal or stomach pain and fullness
  • Scaly skin
  • Seizures
  • Severe stomach pain
  • Shortness of breath
  • Slow or irregular heartbeat (bradycardia, arrhythmias)
  • Sore throat
  • Sores, ulcers, or white spots on the lips or in the mouth
  • Sores, welting, or blisters
  • Stupor
  • Sweating
  • Swelling of the face, ankles, hands, or lower legs
  • Swollen or painful glands
  • Swollen, painful, or tender lymph glands in the neck, armpit, or groin
  • Thirst
  • Tightness in the chest
  • Unpleasant breath odor
  • Unusual bleeding or bruising
  • Unusual weight gains or loss
  • Vomiting of blood or material that looks like coffee grounds
  • Wheezing
  • Yellow eyes or skin (jaundice)

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