Careful administration should be implemented in patients with hepatic impairment and/or renal failure; patients who are taking mercaptopurine and azathioprine; patients under treatment for hypertension or cardiac insufficiency eg, with diuretics or ACE inhibitors, may have some concomitant impairment of renal function and allopurinol should be used with care in this group; patients with disorder of hematopoiesis.
Do not take Allopac other than the stated indications in order to avoid misuse and preserve drug quality.
General Precautions: Allopurinol should be withdrawn immediately when a skin rash or other evidence of sensitivity occurs.
Allopac treatment should not be started until an acute attack of gout has completely subsided, as further attacks may be precipitated.
In the early stages of treatment with Allopac, as with uricosuric agents, an acute attack of gouty arthritis may be precipitated. Therefore, it is advisable to give prophylaxis with a suitable anti-inflammatory agent or colchicine for at least 1 month. The literature should be consulted for details of appropriate dosage, precautions and warnings. It is recommended that the patient start with a low dose of Allopac (100 mg daily) and increase at weekly intervals by 100 mg until a serum uric acid level of ≤6 mg/dL is attained but without exceeding the maximum recommended dose (800 mg/day). If acute attacks develop in patients receiving Allopac, treatment should continue at the same dosage while the acute attack is treated with a suitable anti-inflammatory agent.
A fluid intake sufficient to yield a daily urinary output of at least 2 L and the maintenance of a neutral, or preferably, slightly alkaline urine are desirable to avoid the theoretical possibility of formation of xanthine calculi under the influence of therapy with allopurinol, and help prevent renal precipitation of urates in patients receiving concomitant uricosuric agents.
Periodic liver function tests are recommended during the early stages of therapy.
The dose should be adjusted by monitoring serum urate concentrations and urinary urate/uric acid levels at appropriate levels.
Effects on the Ability to Drive or Operate Machineries: Since adverse reactions eg, somnolence, vertigo and ataxia have been reported in patients receiving Allopac, patients should exercise caution before driving, using machinery or participating in dangerous activities until they are reasonably certain that Allopac does not adversely affect performance.
Use in pregnancy & lactation: Teratogenesis has not been observed in animal tests. Allopac should only be used during pregnancy if the potential benefit justifies the risk to the mother and fetus.
Reports indicate that allopurinol and oxipurinol are excreted in human breast milk. Therefore, Allopac should not be used in nursing mothers.
Use in the elderly: In the absence of specific data, the lowest dosage which produces satisfactory urate reduction should be used.