Urifugan

Allopurinol:

• Pharmacological action
• Pharmacokinetics
• Why is Urifugan prescribed?
• Dosage and administration
• Urifugan (Allopurinol) side effects, adverse reactions
• Urifugan contraindications
• Using during pregnancy and breastfeeding
• Special instructions
• Urifugan drug interactions
• Urifugan in case of emergency / overdose
• Urifugan (Allopurinol) reviews

Pharmacological action

Urifugan is a medication that violates the synthesis of uric acid. This drug is a structural analog of hypoxanthine. It inhibits the enzyme xanthine oxidase, which is involved in the conversion of hypoxanthine to xanthine and xanthine to uric acid. This is due to decrease in the concentration of uric acid and its salts in body fluids and urine, which helps dissolve existing uric acid deposits and prevents their formation in tissues and kidney. Urifugan (Allopurinol) increases urinary excretion of hypoxanthine and xanthine.

Pharmacokinetics

After oral administration Urifugan (Allopurinol) is almost entirely (90%) absorbed from the gastrointestinal tract. This medication is metabolized to form alloxantin, which retains the ability to sufficiently long to inhibit xanthine oxidase. C_max of Urifugan (Allopurinol) in the blood plasma is reached after an average of 1.5 h, alloxantin - in 4.5 h after a single dose.

T_1/2 of Urifugan (Allopurinol) is 1-2 hours, alloxantin - about 15 hours. About 20% of the administered dose is excreted through the intestines and the rest by kidneys.

Why is Urifugan prescribed?

Treatment and prevention of gout and hyperuricemia different genesis (including in conjunction with nephrolithiasis, renal failure, uric acid nephropathy). Recurrent mixed calcium oxalate kidney stones if hyperuricosuria. Increased production of urate due to enzyme disorders. Prevention of acute kidney disease in cytostatic and radiotherapy of tumors and leukemia, as well as full medical starvation.

Dosage and administration

The dosing regimen of Urifugan is set individually under the control of concentrations of urate and uric acid in blood and urine. The ora ldose for adults is 100-900 mg / day depending on the severity of the disease. The frequency of admission is 2-4 times / day after a meal. For children under the age of 15 years - 10-20 mg / kg / day or 100-400 mg / day.

Maximum doses: if renal dysfunction (including due to urate nephropathy) - 100 mg / day. Increasing the dose is possible when on the background of the therapy remains an increased concentration of urate in the blood and urine.

Urifugan (Allopurinol) side effects, adverse reactions

Cardio-vascular system: in single cases - hypertension, bradycardia.

Digestive system: possible dyspepsia (including nausea, vomiting), diarrhea, transient increase of transaminases in blood serum; rarely - hepatitis, in single cases - stomatitis, liver function (transient increase of transaminases and alkaline phosphatase), steatorrhea.

CNS and peripheral nervous system: in single cases - weakness, fatigue, headache, dizziness, ataxia, drowsiness, depression, coma, paresis, paresthesia, seizures, neuropathy, visual impairment, cataracts, changes in the papilla of the optic nerve, disorders of taste sensations.

Hemopoietic system: in some cases - thrombocytopenia, agranulocytosis and aplastic anemia, leukopenia (most likely in patients with impaired renal function).

Urinary system: rarely - interstitial nephritis, in single cases - edema, uremia, hematuria.

Endocrine system: in single cases - sterility, impotence, gynecomastia, diabetes.

Metabolism: in single cases - hyperlipidemia.

Allergic reactions: skin rash, redness, itching; in some cases - angioimmunoblastic lymphadenopathy, arthralgia, fever, eosinophilia, fever, Stevens-Johnson syndrome, Lyell's syndrome.

Dermatological reactions: in rare cases - furunculosis, alopecia, discoloration of hair.

Urifugan contraindications

Pronounced liver function and / or renal disease, pregnancy, lactation, hypersensitivity to Urifugan (Allopurinol).

Using during pregnancy and breastfeeding

Urifugan is contraindicated during pregnancy and lactation (breastfeeding).

Category effects on the fetus by FDA - C.

Special instructions

It is necessary to maintain urine output of at least 2 liters a day and a neutral or slightly alkaline reaction of urine, because it prevents the precipitation of urate and the formation of concretions. You should not begin therapy with Urifugan (Allopurinol) until complete relief of acute attack of gout; during the first month of treatment is recommended prophylactic administration of NSAIDs or colchicine; in the case of an acute attack of gout during therapy was added to the anti-inflammatory drugs. If impaired renal and liver function (increased risk of side effects), the dose is decreased. First 6-8 weeks of treatment need regular liver function tests, and blood diseases require regular laboratory monitoring.

When a skin rash this drug is overturned, after the disappearance of the not copious rash there are possible a reappointment of the drug in its treatment of relapsed immediately terminate.

Use of azathioprine or 6-mercaptopurine on the background of Urifugan (Allopurinol) permits a 4-fold reduction in their doses. This medication combined with a care with vidarabine.

Urifugan drug interactions

With the simultaneous administration Urifugan (Allopurinol) increases the effect of coumarin anticoagulants, adenine arabinoside, as well as hypoglycemic agents (especially if renal impairment).

Uricosuric medicines and salicylates in high doses reduce the activity of Urifugan (Allopurinol) Biogaran.

With the simultaneous administration of Urifugan (Allopurinol) and cytostatics there is often manifested myelotoxic effect than when applied separatively.

With the simultaneous administration of this drug and azathioprine or mercaptopurine it is observed accumulation of the latter in the body, because in connection with the activity of xanthine oxidase inhibition with Urifugan (Allopurinol) necessary to biotransformation of drugs, slowing their metabolism and elimination.

Urifugan in case of emergency / overdose

Symptoms: nausea, vomiting, diarrhea, dizziness, oliguria.

Treatment: forced diuresis, hemodialysis and peritoneal dialysis.