Allopurinol side effects

What Side Effects Allopurinol Can Have?

Below you will find the most important information about possible known side effects of Allopurinol.
These side effects do not occur, but you can. Because every person reacts differently to medication. Please also note that the type and frequency of side effects may vary depending on the drug formulation (eg tablet, syringe, ointment).

At the beginning of the intake: acute attacks of gout in response to the active substance.

Occasional side effects:
nausea, nausea, diarrhea.

Rare side effects:
Dizziness, drowsiness, headache, jaundice, kidney inflammation, seizures, skin lesions with fever, lymphadenopathy, joint pain and blood count changes.

Very rare side effects:
Hypersensitivity reactions with fever, chills and joint pain; Hepatic dysfunction, bile duct inflammation, drowsiness, nervousness, alopecia, discolored hair, weakness, movement disorders, paralysis, cardiac arrhythmia, diabetes mellitus, depression, purulent bumps, changes in taste, breast enlargement in men, vomiting of blood, blood in the urine, increased fat levels in the blood, high blood pressure, impotence , Infertility, blurred vision, cataracts, unconsciousness, myalgia, skin swelling (Quincke’s edema), fatty stools, mouth sores, clouding of consciousness, ejaculation, nerve disorders, gait disturbances, changes in the yellow spot in the eye (macular degeneration), fluid retention, severe skin reactions (hypersensitivity syndrome, Stevens-Johnson syndrome, toxic epidermal necrolysis).

Special Features:
Severe skin reactions that are potentially life-threatening can initially manifest as reddish, bullet-shaped or circular spots (often with a central blister) on the trunk of the body. Additional complaints include open, sore spots in the mouth, throat, nose and pubic area, as well as red and swollen eyes (conjunctivitis). Frequently, these skin reactions are accompanied by flu-like signs. The rash – the risk of which is particularly high in the first weeks of treatment – can lead to large-scale blistering or detachment of the skin. People who are descendants of Han Chinese or Thai people may be at higher risk for these side effects. If the above symptoms appear, the Allopurinol treatment must be stopped immediately and the treating physician informed.

What interactions does allopurinol show?

Please note that the interactions may vary depending on the drug formulation of a drug (eg tablet, syringe, ointment).

The efficacy of allopurinol is diminished by the concomitant administration of agents that increase uric acid excretion. These agents include the gout agents probenecid, benzbromarone and sulfinpyrazone. Also, the effect of allopurinol is reduced with concomitant use of dehydrating thiazides and etacrynic acid.

If allopurinol is administered concomitantly with 6-mercaptopurine or azathioprine, its dose must be reduced as these drugs are broken down more slowly and their effect is prolonged.

If the antibiotics ampicillin or amoxicillin are taken at the same time, allergic reactions (rashes) are increasingly likely. Therefore, patients taking allopurinol should be given other antibiotics.

Anticoagulants such as coumarin or warfarin can be enhanced in their effect. Therefore, a more frequent control of blood coagulation is required and, if necessary, a corresponding dose reduction is necessary.

Especially with impaired kidney function, the hypoglycemic effect of the diabetes drug chlorpropamide may be prolonged by the concomitant administration of allopurinol, which requires a dose reduction.

Allopurinol inhibits the metabolism of the asthma drug Theophylline at high doses. Therefore, at the beginning of treatment with allopurinol or when increasing the allopurinol dose, the theophylline level in the blood should be determined.

When allopurinol and cytostatics are administered, changes in the blood count are more common than when the drugs are given alone. Blood counts should be performed at short intervals.

Potential Allopurinol side effects may include: