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Zyloprim Side Effects

Generic Name: allopurinol

Note: This page contains side effects data for the generic drug allopurinol. It is possible that some of the dosage forms included below may not apply to the brand name Zyloprim.

In Summary

More frequent side effects include: acute gout attack. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to allopurinol: oral capsule, oral tablet

As well as its needed effects, allopurinol (the active ingredient contained in Zyloprim) may cause unwanted side effects that require medical attention.

Severity: Major

If any of the following side effects occur while taking allopurinol, check with your doctor immediately:

More common
  • Ankle, knee, or great toe joint pain
  • joint stiffness or swelling
  • rash
  • rash with flat lesions or small raised lesions on the skin
Rare
  • 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
  • cough or hoarseness
  • coughing up blood
  • cracks in the skin
  • dark urine
  • decreased urine output
  • depression
  • diarrhea
  • difficulty with 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
  • general feeling of tiredness or weakness
  • 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
  • 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 gain or loss
  • vomiting of blood or material that looks like coffee grounds
  • wheezing
  • yellow eyes or skin

Severity: Minor

Some allopurinol side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

Rare
  • Bad, unusual, or unpleasant (after) taste
  • blindness
  • blue-yellow color blindness
  • blurred vision
  • body aches or pain
  • burning feeling in the chest or stomach
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • burning, dry, or itching eyes
  • burning, numbness, tingling, or painful sensations
  • change in taste
  • change in vision
  • congestion
  • continuing ringing or buzzing or other unexplained noise in the ears
  • decreased interest in sexual intercourse
  • decreased vision
  • difficulty with moving
  • discharge or excessive tearing
  • feeling of constant movement of self or surroundings
  • hair loss or thinning of the hair
  • hearing loss
  • hives or welts
  • impaired vision
  • inability to have or keep an erection
  • indigestion
  • lack or loss of strength
  • loss in sexual ability, desire, drive, or performance
  • loss of appetite
  • loss of memory
  • multiple swollen and inflamed skin lesions
  • muscle aching or cramping
  • muscle pain or stiffness
  • muscular pain, tenderness, wasting, or weakness
  • noisy breathing
  • problems with memory
  • redness, pain, or swelling of the eye, eyelid, or inner lining of the eyelid
  • runny nose
  • sensation of spinning
  • sensitivity to light
  • sleepiness or unusual drowsiness
  • sleeplessness
  • sneezing
  • stomach upset
  • stuffy nose
  • sweating
  • swelling of the breasts or breast soreness in both females and males
  • swelling of the salivary glands
  • swelling or inflammation of the mouth
  • swollen joints
  • tearing
  • tender, swollen glands in the neck
  • tenderness in the stomach area
  • throbbing pain
  • tightness in the chest
  • trouble getting pregnant
  • trouble with sleeping
  • trouble with swallowing
  • unable to sleep
  • unsteadiness or awkwardness
  • voice changes
  • weakness in the arms, hands, legs, or feet
  • weight loss

For Healthcare Professionals

Applies to allopurinol: intravenous powder for injection, oral tablet

General

The most commonly reported adverse reactions include skin rash, diarrhea, nausea, alkaline phosphatase, and transaminase elevation.[Ref]

Dermatologic

Skin rash is one of the most common adverse reactions and may occur at any time during treatment. Some skin reactions can be severe and sometimes fatal. In patients with the most severe reactions, systemic symptoms such as fever, chills, arthralgia, cholestatic jaundice, eosinophilia and mild leukocytosis, or leukopenia accompany the rash. Among 55 patients with gout who received this drug for an average of 1 year (3 to 34 months), 3% developed pruritic maculopapular skin eruptions, sometimes scaly or exfoliative. The incidence of skin rash appears to be greater in patients with renal insufficiency.

Angioedema has been reported with and without signs and symptoms of a more generalized hypersensitivity reaction. Skin reactions associated with exfoliation, fever, lymphadenopathy, arthralgia, and/or eosinophilia resembling Stevens-Johnson and/or Lyell syndromes have occurred rarely. Associated vasculitis and tissue responses may manifest as hepatitis, interstitial nephritis, and very rarely epilepsy.[Ref]

Common (1% to 10%): Rash, maculopapular rash
Uncommon (0.1% to 1%): Ecchymosis
Rare (less than 0.1%): Steven-Johnson syndrome, Lyell syndrome
Very rare (less than 0.01%): Alopecia, discolored hair, angioedema, fixed drug eruption
Frequency not reported: DRESS (Drug reaction with eosinophilia and systemic symptoms), sweating[Ref]

Hypersensitivity

Rare (less than 0.1%): Generalized hypersensitivity
Very rare (less than 0.01%): Anaphylaxis, angioedema
Frequency not reported: Hypersensitivity reaction[Ref]

Generalized hypersensitivity including skin reactions associated with exfoliation, fever, lymphadenopathy, arthralgia, and/or eosinophilia resembling Stevens-Johnson and/or Lyell syndromes have occurred rarely. Associated vasculitis and tissue responses may manifest as hepatitis, interstitial nephritis, and very rarely epilepsy. When generalized hypersensitivity reactions have occurred, renal and or/hepatic disorders have often been present, particularly when the outcome has been fatal.

Angioedema has been reported with and without signs and symptoms of a more generalized hypersensitivity reaction.[Ref]

Hepatic

Common (1% to 10%): Increases in alkaline phosphatase and serum transaminases
Rare (less than 0.1%): Hepatic dysfunction including hepatitis (hepatic necrosis and granulomatous hepatitis), hepatomegaly, cholestatic jaundice,
Frequency not reported: Clinical hepatotoxicity, liver failure[Ref]

Liver failure was reported in less than 1% of patients.[Ref]

Gastrointestinal

Common (1% to 10%): Diarrhea, nausea, vomiting
Rare (less than 0.1%): Intermittent abdominal pain, gastritis, dyspepsia
Very rare (less than 0.01%): Steatorrhea, recurrent hematemesis, stomatitis, changed bowel habit
Frequency not reported: Hemorrhagic pancreatitis, gastrointestinal bleeding, salivary gland swelling, tongue edema, anorexia, flatulence[Ref]

Hemorrhagic pancreatitis, gastrointestinal bleeding, salivary gland swelling, tongue edema, flatulence, and anorexia were reported in less than 1% of patients.[Ref]

Hematologic

Eosinophilic fibrohistiocytic lesion of bone marrow, pancytopenia, anemia, hemolytic anemia, reticulocytosis, lymphadenopathy, disseminated intravascular coagulation, and lymphocytosis were reported in less than 1% of patients.[Ref]

Very rare (less than 0.01%): Leukocytosis, leukopenia, eosinophilia, thrombocytopenia, granulocytopenia, agranulocytosis, aplastic anemia
Frequency not reported: Bone marrow depression, eosinophilic fibrohistiocytic lesion of bone marrow, pancytopenia, anemia, hemolytic anemia, reticulocytosis, lymphadenopathy, lymphocytosis, disseminated intravascular coagulation[Ref]

Renal

Common (1% to 10%): Renal failure/insufficiency
Very rare (less than 0.01%): Xanthine crystalluria, azotemia[Ref]

Xanthine crystalluria has been reported in 3 patients; 2 patients with Lesch-Nyhan syndrome and 1 patient with lymphosarcoma who produced an extremely large amount of uric acid during chemotherapy.

Increased serum creatinine and kidney function abnormality has been reported in less than 1% of patients.[Ref]

Nervous system

Uncommon (0.1% to 1%): Headache
Very rare (less than 0.01%): Ataxia, somnolence, coma, paralysis, paresthesia, neuropathy, taste perversion, neuritis
Frequency not reported: Drowsiness, confusion, foot drop, seizure, status epilepticus, myoclonus, twitching, cerebral infarction, stroke, tremor[Ref]

Confusion, foot drop, seizure, status epilepticus, myoclonus, twitching, cerebral infarction, stroke, and tremor were reported in less than 1% of patients.[Ref]

Ocular

Very rare (less than 0.01%): Visual disorder, cataract, macular changes
Frequency not reported: Optic neuritis[Ref]

Immunologic

Very rare (less than 0.01%): Furunculosis, angioimmunoblastic lymphadenopathy[Ref]

Metabolic

Uncommon (0.1% to 1%): Increase in acute gout attacks
Very rare (less than 0.01%): Diabetes mellitus, hyperlipidemia
Frequency not reported: Hypercalcemia, hypocalcemia, hyperphosphatemia, hypokalemia, hyperuricemia, electrolyte abnormality, hyperglycemia, hypernatremia, metabolic acidosis, glycosuria, hyperkalemia, lactic acidosis, water intoxication, hypomagnesemia[Ref]

Early clinical experience with this drug found acute gouty attacks on therapy initiation to be one of the more commonly observed adverse reactions; however, current use analyses suggests this incidence is now less than 1%. The reason for this change has not been determined, but it may be due to patients initiating therapy more gradually.

Hypercalcemia, hypocalcemia, hyperphosphatemia, hypokalemia, hyperuricemia, electrolyte abnormality, hyperglycemia, hypernatremia, metabolic acidosis, glycosuria, hyperkalemia, lactic acidosis, water intoxication, and hypomagnesemia have been reported in less than 1% of patients.[Ref]

Musculoskeletal

Rare (less than 0.1%): Myopathy, arthralgias[Ref]

Cardiovascular

Uncommon (0.1% to 1%): Necrotizing angiitis, vasculitis, edema
Very rare (less than 0.01%): Angina, bradycardia, hypertension
Frequency not reported: Pericarditis, peripheral vascular disease thrombophlebitis, vasodilation, heart failure, cardiorespiratory arrest, decreased venous pressure, flushing, cardiovascular disorder, ECG abnormality, hemorrhage, ventricular fibrillation[Ref]

Pericarditis, peripheral vascular disease thrombophlebitis, vasodilation, heart failure, cardiorespiratory arrest, decreased venous pressure, flushing, cardiovascular disorder, ECG abnormality, hemorrhage, and ventricular fibrillation were reported in less than 1% of patients.[Ref]

Endocrine

Uncommon (0.1% to 1%): Gynecomastia[Ref]

Genitourinary

Uncommon (0.1% to 1%): Infertility, impotence, nocturnal emission
Very rare (less than 0.01%): Uremia, hematuria, male infertility, impotence, erectile dysfunction
Frequency not reported: Urinary tract infection[Ref]

Local

Injection site reactions have been reported with the parenteral product in less than 1% of patients.[Ref]

Frequency not reported: Injection site reactions[Ref]

Other

Uncommon (0.1% to 1%): Fever, general malaise, asthenia
Very rare (less than 0.01%): Vertigo
Frequency not reported: Tinnitus[Ref]

Psychiatric

Very rare (less than 0.01%): Depression
Frequency not reported: Amnesia, insomnia, agitation[Ref]

Amnesia, agitation, and insomnia were reported in less than 1% of patients.[Ref]

Respiratory

Rare (less than 0.1%): Epistaxis
Frequency not reported: Bronchospasm, asthma, pharyngitis, rhinitis, respiratory failure/insufficiency, ARDS, increased respiration rate, apnea[Ref]

Bronchospasm, asthma, pharyngitis, respiratory failure/insufficiency, ARDS, increased respiration rate, apnea, and rhinitis were reported in less than 1% of patients.[Ref]

References

1. "Product Information. Zyloprim capsules (allopurinol)." Glaxo Wellcome, Research Triangle Park, NC.

2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

3. Cerner Multum, Inc. "Australian Product Information." O 0

It is possible that some side effects of Zyloprim may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.

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