"The U.S. Food and Drug Administration today approved Krystexxa (pegloticase) to treat the painful condition known as gout in adults who do not respond to or who cannot tolerate conventional therapy.
Gout occurs due to an excess of the b"...
Zyloprim Side Effects Center
Medical Editor: Charles Patrick Davis, MD, PhD
Zyloprim (allopurinol) is a xanthine oxidase inhibitor that reduces the production of uric acid. Zyloprim is used to prevent gout attacks by reducing uric acid production; high levels of uric acid may cause gout or kidney stones. Zyloprim is available as a generic termed allopurinol. Side effects of Zyloprim include drowsiness, headache, diarrhea, vomiting, stomach discomfort, changes in your sense of taste, or muscle pain.
Zyloprim is available in 100 and 300 mg strength tablets. The usual doses start at 200 - 300 mg per day; dosage for children with hyperuricemia under 6 years old is 150 mg per day. Zyloprim is usually recommended to be taken after a meal. Some serious side effects of Zyloprim may include swelling of mouth and lips, severe skin rashes, infections, eye irritation, hepatitis, appetite and weight loss, and painful or bloody urination. Zyloprim should be used during pregnancy only if clearly needed and used with caution in women who are breastfeeding; benefits vs. harm to the fetus or infant should be considered. Zyloprim has been used in certain pediatric patient populations with hyperuricemia.
Our Zyloprim Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What is Patient Information in Detail?
Easy-to-read and understand detailed drug information and pill images for the patient or caregiver from Cerner Multum.
Zyloprim in Detail - Patient Information: Side Effects
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Stop using allopurinol and call your doctor at once if you have a serious side effect such as:
- fever, sore throat, and headache with a severe blistering, peeling, and red skin rash;
- the first sign of any skin rash, no matter how mild;
- pain or bleeding when you urinate;
- nausea, upper stomach pain, itching, loss of appetite, weight loss, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);
- urinating less than usual or not at all;
- joint pain, flu symptoms;
- severe tingling, numbness, pain, muscle weakness; or
- easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin.
Less serious side effects may include:
- vomiting, diarrhea;
- drowsiness, headache;
- changes in your sense of taste; or
- muscle pain.
Read the entire detailed patient monograph for Zyloprim (Allopurinol)
What is Patient Information Overview?
A concise overview of the drug for the patient or caregiver from First DataBank.
Zyloprim Overview - Patient Information: Side Effects
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor immediately if any of these rare but very serious side effects occur: numbness/tingling of arms/legs, easy bleeding/bruising, signs of infection (e.g., fever, persistent sore throat), unusual tiredness, painful/bloody urination, change in the amount of urine, yellowing eyes/skin, severe stomach/abdominal pain, persistent nausea/vomiting, dark urine, unusual weight loss, eye pain, vision changes.
A very serious (possibly fatal) allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Read the entire patient information overview for Zyloprim (Allopurinol)
What is Prescribing information?
The FDA package insert formatted in easy-to-find categories for health professionals and clinicians.
Zyloprim FDA Prescribing Information: Side Effects
Data upon which the following estimates of incidence of adverse reactions are made are derived from experiences reported in the literature, unpublished clinical trials and voluntary reports since marketing of ZYLOPRIM (allopurinol) began. Past experience suggested that the most frequent event following the initiation of allopurinol treatment was an increase in acute attacks of gout (average 6% in early studies). An analysis of current usage suggests that the incidence of acute gouty attacks has diminished to less than 1%. The explanation for this decrease has not been determined but may be due in part to initiating therapy more gradually (see PRECAUTIONS and DOSAGE AND ADMINISTRATION).
The most frequent adverse reaction to ZYLOPRIM (allopurinol) is skin rash. Skin reactions can be severe and sometimes fatal. Therefore, treatment with ZYLOPRIM (allopurinol) should be discontinued immediately if a rash develops (see WARNINGS). Some patients with the most severe reaction also had fever, chills, arthralgias, cholestatic jaundice, eosinophilia and mild leukocytosis or leukopenia. Among 55 patients with gout treated with ZYLO-PRIM for 3 to 34 months (average greater than 1 year) and followed prospectively, Rundles observed that 3% of patients developed a type of drug reaction which was predominantly a pru-ritic maculopapular skin eruption, sometimes scaly or exfolia-tive. However, with current usage, skin reactions have been observed less frequently than 1%. The explanation for this decrease is not obvious. The incidence of skin rash may be increased in the presence of renal insufficiency. The frequency of skin rash among patients receiving ampicillin or amoxicillin concurrently with ZYLOPRIM (allopurinol) has been reported to be increased (see PRECAUTIONS).
Most Common Reactions* Probably Causally Related:
Metabolic and Nutritional: Acute attacks of gout.
Skin and Appendages: Rash, maculopapular rash.
*Early clinical studies and incidence rates from early clinical experience with ZYLOPRIM (allopurinol) suggested that these adverse reactions were found to occur at a rate of greater than 1%. The most frequent event observed was acute attacks of gout following the initiation of therapy. Analyses of current usage suggest that the incidence of these adverse reactions is now less than 1%. The explanation for this decrease has not been determined, but it may be due to following recommended usage (see ADVERSE REACTIONS introduction, INDICATIONS AND USAGE, PRECAUTIONS, and DOSAGE AND ADMINISTRATION).
Incidence Less Than 1% Probably Causally Related:
Body As a Whole: Ecchymosis, fever, headache.
Hemic and Lymphatic: Thrombocytopenia, eosinophilia, leukocytosis, leukopenia.
Musculoskeletal: Myopathy, arthralgias.
Skin and Appendages: Erythema multiforme exudativum (Stevens-Johnson syndrome), toxic epidermal necrolysis (Lyell's syndrome), hypersensitivity vasculitis, purpura, vesicular bullous dermatitis, exfoliative dermatitis, eczematoid dermatitis, pruritus, urticaria, alopecia, onycholysis, lichen planus.
Special Senses: Taste loss/perversion.
Incidence Less Than 1% Causal Relationship Unknown:
Body As a Whole: Malaise.
Hemic and Lymphatic: Aplastic anemia, agranulocytosis, eosinophilic fibrohistiocytic lesion of bone marrow, pancyto-penia, prothrombin decrease, anemia, hemolytic anemia, reticu-locytosis, lymphadenopathy, lymphocytosis.
Skin and Appendages: Furunculosis, facial edema, sweating, skin edema.
Read the entire FDA prescribing information for Zyloprim (Allopurinol)
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