Zyloric – Allopurinol uses, dose and side effects


100 mg and 300 mg tablets

What Zyloric is and what it is used for

Zyloric contains the active substance allopurinol. It works by slowing down various chemical reactions in the body to lower the level of uric acid in the blood and urine and prevents the formation of uric acid crystals.

Zyloric is used for gout and other conditions associated with an excess of uric acid in the body, for example, kidney stones, and certain kidney diseases. It is also used as a preventive treatment against elevated uric acid levels as a result of the treatment of tumor diseases.

What you need to know before you use Zyloric

Do not use Zyloric

– if you are allergic to allopurinol or any other ingredient in this medicine (listed in section 6).

Warnings and precautions

Talk to your doctor before taking Zyloric:

  • if you have impaired liver or kidney function.
  • if you have an ongoing gout attack.
  • if you are of Han Chinese, Thai or Korean descent.
  • if you have thyroid problems.

During treatment with Zyloric:

  • Serious skin rashes (hypersensitivity syndrome, Stevens-Johnson syndrome, toxic epidermal necrolysis ) have been reported when using Zyloric. Often the rash can include sores in the mouth, throat, nose, and genitals, and conjunctivitis (red and swollen eyes). These severe skin rashes are often preceded by flu-like symptoms such as fever, headache, and body aches. The rash can develop into extensive blistering and scaling of the skin. These serious skin reactions may be more common in people of Han Chinese, Thai or Korean descent. Chronic kidney disease may further increase the risk in these patients. If you develop a rash or these skin symptoms, stop taking Zyloric and see a doctor immediately.
  • If you have cancer or Lesch-Nyhan syndrome, xanthine, a precursor to uric acid, can accumulate in the body. To avoid xanthine precipitation in the urinary tract, it is therefore important to drink enough.
  • If you have kidney stones, the kidney stones can become smaller and enter the urinary tract, which can cause problems.

Other medicines and Zyloric

The effect of the treatment can be affected if Zyloric is taken at the same time as other medicines. Tell your doctor or pharmacist if you are taking, have recently taken, or might take any other medicines:

  • azathioprine (used to suppress the immune system)
  • cytostatics (used to treat cancer): When Zyloric and cytostatics are used together (eg cyclophosphamide, doxorubicin, bleomycin, procarbazine, alkyl halides) blood dyscrasias occur more often than when these active substances are used separately. The blood values ​​should therefore be checked regularly.
  • mercaptopurine (used to treat blood cancer ( leukemia )
  • cyclosporine (used to suppress the immune system, for example after organ transplantation and in rheumatism)
  • didanosine (used to treat HIV infection )
  • theophylline (used to treat asthma )
  • vidarabine (used to treat viral infections)
  • phenytoin (used in epilepsy )
  • blood thinners such as warfarin
  • probenecid (used to treat gout )
  • chlorpropamide (used to treat diabetes )
  • diuretics, ACE inhibitors (medicines to treat heart problems or high blood pressure )
  • salicylates in high doses (used for pain relief, to reduce swelling, and to lower body temperature)
  • ampicillin or amoxicillin (medicines used to treat infections ). The risk of allergic rashes may increase with simultaneous treatment with Zyloric.

If aluminum hydroxide (used to neutralize stomach acid) is taken at the same time, the effect of Zyloric may be reduced. There should be at least 3 hours between taking these two medicines.

Pregnancy, breastfeeding, and fertility

If you are pregnant or breastfeeding, think you may be pregnant, or are planning to have a baby, consult your doctor before using this medicine.

Limited experience of use during pregnancy.

Zyloric is excreted in breast milk. Zyloric is not recommended during breastfeeding.

Driving ability and use of machinery

Drowsiness, dizziness, and inability to coordinate movements have occurred during treatment with Zyloric. This should be taken into account when increased attention is required, e.g. when driving and handling machinery. You are responsible for assessing whether you are fit to drive a motor vehicle or perform work that requires increased attention. One of the factors that can affect your ability in these respects is the use of drugs due to their effects and/or side effects. A description of these effects and side effects can be found in other sections. Read all the information in this leaflet for guidance. Discuss with your doctor or pharmacist if you are unsure.

Zyloric contains excipients

Zyloric contains lactose

If you have an intolerance to some sugars, you should consult your doctor before taking this medicine.

How to use Zyloric

Always take this medicine as directed by your doctor. Consult a doctor if you are unsure.

The dose is determined by the doctor who adjusts it individually for you. Dosage one should be adjusted by the doctor during treatment after measuring the level of uric acid salts and uric acid in blood and urine.

The doctor usually starts with a low dose of allopurinol (eg 100 mg/day) to reduce the risk of possible side effects. Your dose will be increased as needed.


You usually start with a low dose, for example, 100 mg daily. If necessary, the dose can be gradually increased to 900 mg daily. Doses above 300 mg should be divided over the day.

To avoid possible nausea and vomiting, you should take the tablets after a meal with a glass of water.

The break score is not for dividing the tablet into equal doses, but only to facilitate swallowing.


You will receive the lowest dose of Zyloric that is effective enough for you.

Impaired kidney or liver function

The doctor can lower the dose or decide that a longer time should pass between doses if you have impaired liver or kidney function.

Use for children and adolescents

Zyloric is rarely used in children, except in certain types of cancer (especially leukemia ) and certain enzyme disorders such as Lesch-Nyhan syndrome.

The recommended dose for children 6–10 years old is 100 mg 3 times daily.

If you use too much Zyloric 

If you have ingested too much medicine or if, for example, a child has ingested the medicine by mistake, contact a doctor or hospital for an assessment of the risk and advice.

Signs of overdose may include nausea, vomiting, diarrhea, and dizziness.

If you forget to use Zyloric

If you forget to take a tablet, take one as soon as you remember. However, skip the missed dose if it is almost time to take the next tablet. Do not take a double dose to make up for a missed dose.

If you stop using Zyloric

Do not stop taking the tablets without talking to your doctor first.

If you have any further questions about this medicine, ask your doctor or pharmacist.

Possible side effects

Like all medicines, this medicine can cause side effects, although not everybody gets them.

Stop taking Zyloric and contact your doctor or hospital immediately if you experience any of the following symptoms:

  • Allergic reactions ( hypersensitivity reaction ). Symptoms of an allergic reaction may include swelling of the eyelids, face, or lips, low blood pressure, palpitations, sudden itchy rash (hives), sudden wheezing, chest tightness, shortness of breath, and dizziness. (Uncommon side effects – may affect up to 1 in 100 users).
  • Severe allergic reaction causing swelling of the face, tongue, or throat; difficulty swallowing; hives and difficulty breathing. May be a sign of angioedema (A very rare side effect – that may affect up to 1 in 10,000 users).
  • Sometimes Zyloric can affect the blood, which can show up in the way that you bruise more easily than usual or that you get an infection with symptoms such as fever with a greatly worsened general condition or fever with local symptoms of infection such as sore throat/pharynx/mouth or severe to pee These effects usually occur in people with liver or kidney problems. Tell the doctor as soon as possible so that a blood test can rule out a lack of certain blood cells ( thrombocytopenia, agranulocytosis, or aplastic anemia ). It is important that you then information about your medication. (Very rare side effects – may affect up to 1 in 10,000 users).
  • Skin changes or an extremely strong allergic reaction with skin rashes usually in the form of blisters or sores in the mouth and eyes as well as other mucous membranes such as the genitals. Or a serious widespread skin injury (skin peeling of the epidermis and superficial mucous membranes). Maybe a sign of erythema multiforme, Stevens-Johnson syndrome, or Lyell’s syndrome ( toxic epidermal necrolysis ) (Rare side effects – may occur in up to 1 in 1000 users).
  • Serious, potentially life-threatening allergic reaction (Very rare side effects – may affect up to 1 in 10,000 users).

Other side effects that may occur:

Common (may affect up to 1 in 10 users):

  • rash
  • increased level of thyroid-stimulating hormone in the blood.

Uncommon (may affect up to 1 in 100 users):

  • nausea, vomiting, and diarrhea
  • impact on liver function.

Rare (may affect up to 1 in 1,000 users).

  • inflammation of the liver ( hepatitis )
  • changes in the skin or mucous membranes, such as red or bumpy rash, widespread blistering or peeling, itching, redness, sores in the mouth, throat, nose, genitals, or conjunctivitis (red and swollen eyes).

Very rare (may affect up to 1 in 10,000 users):

  • blood in the urine
  • vomiting blood (hematemesis)
  • elevated cholesterol levels in the blood
  • a general feeling of sickness or weakness
  • drowsiness, headache, taste changes
  • dizziness
  • unconsciousness, difficulty moving (paralysis)
  • seizures ( spasms, attacks)
  • muscle pain
  • pressure on the chest, slow heart rate, increased blood pressure, blood vessel inflammation
  • swelling of the mouth and lips ( stomatitis )
  • swelling, usually in the legs, feet, or hands ( edema )
  • thirst, fatigue, and weight loss (these may be symptoms of diabetes ); your doctor may want to measure your blood sugar level if this occurs
  • kidney inflammation
  • kidney failure
  • impact on the lymph nodes
  • male infertility or erectile dysfunction ( impotence )
  • tenderness and swelling of the breasts, in both men and women
  • changed bowel movements/bowel habits
  • visual disturbances
  • hair loss, discolored hair
  • Depression
  • disturbances in muscle coordination
  • tingling and burning sensation and numbness in the skin ( paresthesia )
  • stones in the urinary tract
  • boils ( furunculosis ).
  • fat in the stool ( steatorrhoea )
  • increase in urea and creatinine in the blood (azotemia)
  • joint pains
  • increased body temperature (fever).

Not known (frequency cannot be estimated from the available data): Aseptic meningitis ( inflammation of the membrane that surrounds the brain and spinal cord): symptoms include neck stiffness, headache, nausea, fever, or impaired consciousness. Seek medical attention immediately if this occurs.

How to store Zyloric

Keep this medicine out of the sight and reach of children.

Use before the expiry date stated on the carton. The expiration date is the last day of the specified month.

Medicines must not be thrown into the drain or among the household waste. Ask the pharmacist how to dispose of medicines that are no longer used. These measures will help to protect the environment.

Contents of the packaging and other information

Contents declaration

  • The active substance is allopurinol. One tablet contains 100 mg and 300 mg of allopurinol respectively.
  • Other ingredients: lactose monohydrate, magnesium stearate, povidone, and corn starch.

Appearance and package sizes of the medicine

The 100 mg tablet is white to yellowish-white, round with a score line, and marked Z1.

The 300 mg tablet is white to yellowish-white, round with a score line, and marked Z3.

The break score is not for dividing the tablet into equal doses, but only to facilitate swallowing.

Pressed packaging with 100 tablets.

Marketing authorization holder and manufacturer

Aspen Pharma Trading Limited

3016 Lake Drive

Citywest Business Campus

Dublin 24, Ireland

Phone: +46 856 642 572


Aspen Bad Oldesloe GmbH,

Industriestrasse 32-36,

23843 Bad Oldesloe, Germany

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