Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020438 (hypercalciuria)
 2,502 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ketoconazole was used to probe the pathogenetic importance of the serum 1,25-dihydroxyvitamin D [1,25-(OH)2D] concentration in 19 patients with well characterized absorptive hypercalciuria (AH). Patients were studied while receiving a constant metabolic diet before and after 2 weeks of ketoconazole administration (600 mg daily). Twelve of the patients were classified as ketoconazole responders, because in conjunction with a reduction of serum 1,25-(OH)2D from 113 +/- 36 to 70 +/- 26 pmol/L, intestinal 47Ca absorption decreased from 76.3 +/- 8.1% to 61.9 +/- 7.7%, and 24-h urinary Ca excretion declined from 7.6 +/- 1.4 to 5.7 +/- 1.1 mmol (P < 0.001 each). In these patients, intestinal 47Ca absorption was directly correlated with serum 1,25-(OH)2D levels and 24-h Ca excretion. In another group of 7 patients, termed ketoconazole nonresponders, despite reduction of 1,25-(OH)2D from 122 +/- 36 to 84 +/- 17 pmol/L (P = 0.015), there was no significant change in intestinal Ca absorption (76.0 +/- 8.2% to 72.1 +/- 10.6%) or 24-h urinary Ca excretion (7.3 +/- 1.3 to 7.2 +/- 1.0 mmol). In these patients, neither intestinal Ca absorption nor urinary Ca excretion was correlated with serum 1,25-(OH)2D levels. It, thus, appears that AH is a heterogeneous disorder comprised of both vitamin D-dependent and vitamin D-independent subsets. Although useful to probe the pathogenesis of AH, chronic treatment with ketoconazole is not recommended because of its generalized effects in inhibiting steroid synthesis.
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PMID:Use of ketoconazole to probe the pathogenetic importance of 1,25-dihydroxyvitamin D in absorptive hypercalciuria. 146 46

A 47-year-old patient presented with hypercalcemia secondary to sarcoidosis and was successfully treated with 1 year of corticosteroids leading to improvement in his hypercalcemia, hypercalcuria, and elevated levels of 1,25-dihydroxyvitamin D. Angiotensin-converting enzyme levels (ACE) normalized and serum creatinine improved. When hypercalcemia recurred after a 3-year symptom-free interval, the patient refused repeat corticosteroid treatment and was placed on ketoconazole (initially 600 and eventually 800 mg/d). Ketoconazole controlled the patient's hypercalcemia (serum calcium, 3.2 to 2.6 mmol/L [12.8 to 10.4 mg/dL]), but only the larger dose suppressed serum 1,25-dihydroxyvitamin D levels into the normal range. Hypercalcuria was markedly improved with ketoconazole, decreasing from a peak of 23 mmol/d (940 mg/d) to less than 8.7 mmol/d (350 mg/d) on a dose of 800 mg. However, serum ACE levels remained elevated on ketoconazole. An attempt to taper the ketoconazole after 1 year resulted in rapid recurrence of hypercalcemia (serum calcium, 2.8 mmol/L [11.1 mg/dL]) and hypercalcuria (urinary calcium excretion, 11 mmol/d [451 mg/d]). After a total of 2 years of ketoconazole treatment, his defect in calcium metabolism remains well controlled despite persistent elevation in ACE levels. Serum cortisol levels and liver function tests remain normal on therapy, although there has been a slight decrease in serum testosterone levels accompanied by some decrease in libido. These data suggest that long-term use of ketoconazole may be a safe and effective alternative to corticosteroid treatment for sarcoid-associated hypercalcemia. Further study is needed to determine whether the long-term side effects of ketoconazole therapy or its failure to control disease activity in sarcoidosis outweigh its advantages in avoiding the known side effects of glucocorticoids.
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PMID:Treatment of sarcoidosis-associated hypercalcemia with ketoconazole. 196 57