Thiazide diuretics gout with

Allopurinol is used to lower uric acid levels in the treatment of primary gout, as a prophylaxis in myeloproliferative neoplastic disease, for investigational purposes in Lesch-Nyhan syndrome, and as an adjunct with thiazide diuretics or ethambutol (see Chapter 24). Allopurinol acts by inhibiting xanthine oxidase, which converts hypoxanthine into xanthine and in turn becomes oxidized into uric acid. 

The special risk is observed in patients with hepatic or renal impairment. It is not advised to use allopurinol in acute attacks of gout, but it is useful in chronic gout. Excretion of allopurinol and its active metabolite oxypurinol is primarily via the kidneys and therefore the dosage should be reduced if renal function is impaired. The adverse effects have been reported in patients receiving allopurinol with thiazide diuretics, particularly in patients with impaired renal function. The metabolism of azathioprine and mercaptopurine is inhibited by allopurinol and their doses should be reduced to one-quarter to one-third of the usual dose when either of them is given with allopurinol to avoid potentially life-threatening toxicity.27-29... 

Correct answer = D. Among black patients, diuretic and calcium channel blockers are more effective than ACE inhibitors or p-blockers. Diuretics are effective among the elderly. Thiazide diuretics cause hyperuricemia and can precipitate a gout attack in susceptible individuals. Thiazide diuretics increase LDL cholesterol and may increase the risk of atherosclerosis in patients with hyperlipidemia. Patients with evidence of elevated catecholamines are best treated with p-blockers. Thiazides cannot promote sodium excretion when renal function is severely impaired. The loop diuretics, such as furosemide, are used in patients with impaired renal function. 

Thiazide diuretics cause hjrperuricemia and can occasionally precipitate gout (21). They can also cause renal stones (22). Uric acid precipitation is not normally a problem, although it was with the uricosuric drug tieniUc acid. Renal vasculitis due to thiazides is rare (SEDA-18,234). 

ADVERSE EFFECTS AND PRECAUTIONS Adverse effects of diuretics see Chapter 28) determine tolerance and adherence. Erectile dysfunction is a troublesome adverse effect of thiazide diuretics physicians should inquire specifically regarding its occurrence. Albeit uncommon, gout may be a consequence of the hyperuricemia induced by these diuretics. Either of these adverse effects is reason to consider alternative therapies. Hydrochlorothiazide may cause rapidly developing, severe hyponatremia in some patients. Thiazides inhibit renal Ca " excretion, occasionally leading to hypercalcemia although generally mUd, this can be more severe in patients subject to hypercalcemia, such as those with primary hyperparathyroidism. The thiazide-induced decreased Ca excretion may be used therapeutically in patients with osteoporosis or hypercalciuiia. 

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