Allopurinol is a drug that can effectively reduce the concentration of uric acid. This prevents the deposition of salts of uric acid in the kidneys, bladder and joints. One of the most famous ailments of the genitourinary system is urolithiasis. The disease is very diverse, as the stones in the kidney and bladder can have a variety of nature and, accordingly, require a different treatment. Allopurinol is a drug that prevents the deposition and increase of urates.
Allopurinol
The mechanism of urate formation - salts of uric acid and sodium or potassium, has been studied little. It is known only that against a background of insufficient consumption of water, uric acid in urine accumulates in too high a concentration and increases the acidity of urine. As a result, its sodium and potassium salts precipitate. Moreover, salts can be deposited not only in the bladder or kidneys, but also in the joints, causing such an unpleasant disease as gout.
And this enzyme is in turn responsible for oxidizing hypoxanthin and converting it into xanthine. Without it, the reaction does not occur or is carried out in too low a volume, as a result, the synthesis of uric acid is disrupted and this substance is produced in less quantity.
Thus, the uric acid concentration in urine is reduced, the pH is lowered and, accordingly, the urate is dissolved.
The medication is prescribed for patients whose illness is associated with an increase in the concentration of uric acid:
- urate nephropathy is acute and chronic. Urates in the form of crystals are deposited in the distal tubules and collecting tubes. Urats provoke canal obstruction, atrophy of the kidney tissue. Along the crystals accumulate foreign cells - giant, mononuclear;
- urate stone disease - nephrolithiasis. It is caused by calcifications in the kidney or urinary tract concrements up to a few centimeters in diameter. The composition of the stone always includes the organic and inorganic parts. According to statistics, urate stones are rare - only 5% of all cases;
- gout - with a constant and sufficiently high level of uric acid, urates are formed in all joints and other organs. The development of the disease is fraught with the complete destruction of the joints;
- congenital anomalies - Leschy-Nyen syndrome, adenine phosphoribosyltransferase deficiency.
In such cases, when the amount of uric acid can not be reduced by compliance with the diet, allopurinol is prescribed.
Composition of
The preparation is produced in two forms: allopurinol 100 and allopurinol 300.
Tablet contains:
- allopurinol or 1-H-pyrazolo( 3,4-d) -pyrimidin-4-ol - 100 or 300 mg respectively;
- additional ingredients - lactose, starch, talc, magnesium stearate, polyvidone, sodium amylopectin glycolate. The tablet does not include lactose in 300 mg. These substances serve only as a protective shell, ensuring the delivery of the drug into the small intestine and 12-colon, where the absorption of the drug occurs.
Form
The drug is available in tablets, 30 or 50 pcs. Each.in a pack. Blister packaging is offered - 3-5 in a box, or 1 bottle. The tablet is covered with a white sheath. The shelf life of the product is 5 years from the date of issue.
The price is determined by the dosage of the active substance, the manufacturer and the number of tablets in the package:
- allopurinol 100 50 pcs.costs from 72 to 95 r.for packing;
- З0 pcs.allopurinol 300 cost from 85 to 117 r.for packing;
- price is 50 pcs. Allopurinol 300 is in the 268-400 p.
Mechanism of Action
Allopurinol, as well as the result of its decay - oxypurinol, acts as an inhibitor of xanthine oxidase. Restricting the action of the enzyme, the substance prevents the conversion of xanthine to uric acid, which leads to a decrease in concentration. The process of disintegration occurs very quickly, just under the influence of xanthine oxidase - in fact, the drug gives the enzyme the opportunity to "work" with it instead of xanthines. Accordingly, the amount of urate in the blood decreases, which prevents deposition of salts in the tissues.
Allopurinol is actively absorbed into the blood: an hour and a half after consumption, the maximum concentration is observed. The substance has a fairly short half-life - 2 hours, mostly removed with urine - 80%.The rest is excreted with feces. The substance does not bind to plasma proteins: after 5-7 days of the course, only about 3% of the substance is excreted in a bound form.
The drug metabolite product, oxypurinol, has a longer half-life of almost 15 hours. With proteins, he also does not bind and almost completely removed with urine in an unbound form.
The drug accumulates in the body. To achieve a stable, pronounced effect, it takes about 7 days, so the course of therapy can not be less than 3 weeks, otherwise the result will be very short-lived.
On average, 60-70% of the dose is in the urine in the form of oxypurinol, and 6-15% is removed unchanged. If the kidneys are disturbed, the half-life period increases significantly.
Indications
The drug is used for almost all forms of primary - gouty, and secondary hyperuricemia, and sometimes even for preventive purposes with a large amount of uric acid.
The list of indications for use is quite impressive:
- gout - is prescribed even against a background of kidney failure;
- renal stone disease - with the formation of urates;
- lymphosarcoma, acute leukemia,
- chronic myelogenous leukemia;
- traumatic injuries;
- cytostatic and radiotherapy;
- Lesha-Niena syndrome;
- massive glucocorticoid therapy;
- is a uric acid nephropathy.
Instructions for use
Tablets should be taken after meals and washed down with plenty of water. The latter is a fundamental requirement: in the treatment of allopurinol, the daily volume of urine should reach 2 liters. The urine reaction is also important: under the action of the drug, it must become neutral or slightly alkaline.
How to take and how much the doctor prescribes.
Adult
The course begins always with a minimum dose of 100 mg to identify side effects and prevent complications. If no negative effects were found, the dose of the drug is calculated by the amount of uric acid in the blood. Increase it stepwise, at 100 mg per day, until a therapeutic effect is obtained.
The minimum amount is 100 mg per day, the maximum is 800 mg.
- Primary hyperuricemia - with a low severity - hyperuricemia up to 7 mg%, prescribe 200-400 mg per day. The course usually lasts 3-4 weeks. Then the dose is reduced to 100 mg per day.
- With hyperuricemia above 7 mg%, the dose is increased to 600-800 mg. The drug is taken 3-4 times a day, not more than 200 mg at a time. This regime lasts up to 4 weeks. Then the patient is transferred to a maintenance dose of 100-200 mg.
Supportive therapy can last several months. You can not skip the reception, since in the absence of the drug the ailment appears again for 3-4 days.
- For preventive purposes - with radiation therapy, for example, appoint 400 mg per day. The course begins several days before therapy, continues during the course of treatment and ends a few days after irradiation.
- For renal failure medication is prescribed depending on the magnitude of creatinine clearance:
- at a blood flow rate of more than 20 ml / min, the dose can be no more than 300 mg per day;
- at clearance of 10-20 ml / min - limited to 200 mg;
- with clearance less than 10 ml / min allopurinol is prescribed not more than 100 mg.
If necessary, the quantity increases, but in this case the interval between doses increases every 48-72 hours.
- With hemodialysis appoint 300-400 mg after each procedure.
Indication for a decrease in dose is the level of oxypurinol in the blood - no more than 15 mcg / ml.
Children of
Allopurinol is prescribed to children under 14 years of age only with cytostatic therapy of leukemia or with enzymatic disorders if there is no alternative.
The dosage of the drug is calculated by body weight - 10-20 mg / kg. In any case, the maximum dose can not exceed 400 mg.
The drug is taken for 3 doses. A recommendation for sufficient fluid intake must be carried out.
Elderly
The restriction in this case is the reduced functionality of the kidney. Allopurinol is prescribed in the minimum therapeutic dose. If necessary, increase the time interval between doses.
Side effects of
Allopurinol infrequently causes similar actions. It is worth remembering that the exacerbation of gout at the first stage to those does not apply. This is a short-term phenomenon and, in fact, is a reaction to a sharp change in acidity.
Significant side effects include the following:
- hemopoiesis - anemia, agranulocytosis, leukocytosis, thrombocytopenia;
- cardiovascular system - the most common effect is to increase blood pressure. Possible bradycardia, pericarditis;
- genito-urinary system - allopurinol can cause acute renal failure, proteinuria, decreased potency, peripheral edema, possibly detecting blood in the urine;
- sense organs - decreased vision, loss or distortion of taste sensations, amblyopia;
- digestive tract - nausea, vomiting, diarrhea, cholestatic jaundice develops;
- nervous system - neuropathy, headache, drowsiness. With high sensitivity, depression appears;
- allergic reactions - rash, itching, hives, purpura, various forms of dermatitis. This reaction is most pronounced and is most easily traced.
Against the background of renal failure, possible side effects are more common.
Contraindications
There are a number of indications in which the use of allopurinol in treatment is prohibited:
- Absolute contraindication is the presence of intolerance to allopurinol or an additional component.
- Do not administer medication for severe liver damage, with acute and chronic renal dysfunction - if creatinine clearance does not exceed 2 ml / min.
- If the value of uric acid can be regulated by diet, allopurinol is not assigned.
- The substance is found in breast milk, so it can not be used while breastfeeding. Studies on pregnant women have not been conducted, but still the use of the substance is considered undesirable.
- Acute gout is also a contraindication. Treatment is prescribed only after improvement.
- Primary hemahromatosis is a genetic disease due to which iron is excessively absorbed from food and deposited in tissues. In this case, it is prohibited to use allopurinol. The same applies to cases when the hemahromatosis is noted in relatives.
Special instructions
Allopurinol indirectly affects the water balance and promotes dehydration, and therefore the most important requirement for treatment is the intake of sufficient water. The volume of daily urine can not be less than 2 liters - this is an absolute requirement.
Other requirements are no less categorical:
- The drug is not compatible with alcohol, so the latter should be discarded.
- Because the drug causes, or rather, can cause drowsiness and dizziness, while taking medicine for driving should be discarded. How strictly you need to comply with this prohibition, can only tell the supervising physician.
- If there are any factors contributing to the reduction of renal function - the use of diuretics, elderly age, hypertensive therapy, it is necessary to carefully calculate the dose and monitor the patient's condition. If any signs of an allergy or a violation of functionality appear, the drug is immediately withdrawn.
- If the agent is prescribed against the background of disorders in the hematopoietic system, then it is necessary to follow the blood formula additionally. For example, consider the presence of lactose in a 100 mg tablet when preparing a diet for such a patient.
It is necessary to take into account the incompatibility of allopurinol with a number of medications:
- sulfinpyrazone - the effectiveness of allopurinol decreases;
- anticoagulants of indirect action - difekin, theophylline. Allopurinol enhances their effects, including negative ones;
- 6-mercaptopurine, azathioprine - drug increases the toxicity of the drug, so that when taken together the dose of drugs should be reduced to ¼-1/3 of the usual;
- thiazide diuretics, furosemide, methacrylic acid - increase the concentration of uric acid, which is directly opposite the action of allopurinol;
- ampicillin, amoxicillin - when combined, the risk of skin reactions is high.
The intake of 20 g of the drug causes poisoning: vomiting, dizziness, nausea, fever. Against the background of renal failure, poisoning can occur with a lower dose. The substance has no specific antidote. With the intoxication cope with the usual methods: washing, a dropper with saline solution, perhaps the appointment of dialysis.
Analogues
In addition to the described preparation, allopurinol as an active substance contains:
- allplol;
- alopron;
- purinol;
- allopurinol aegis;
- sanipipurol.
Reviews
Allopurinol is a well-proven remedy, but miracles are also beyond its control. Like any other medicine, the medicine has its effect only if certain conditions are met.
- Its plus is the ability to take a dose at a time, if it does not exceed 300 mg in knocking. This minimizes the risk of missing the medication.
- The disadvantage of the patients' reviews is the duration of a sustained therapeutic effect: the drug must accumulate in order to have the maximum effect. In addition, take the pill will take a long time.
- With gout, allopurinol or its analogs must be taken almost all of life. With urolithiasis, various forms of urate nephropathy, the prognosis is more encouraging: it is necessary to achieve dissolution of urates and a steady decrease in uric acid.
- Allopurinol in any way does not cancel the diet. In fact, if the restriction in food is not respected, the drug will be ineffective.
Allopurinol is a drug that helps to reduce uric acid levels and remove urate stones. The drug is equally effective for gout and urolithiasis, but its use is possible only after the appointment of a doctor.