A systematic review and meta-analysis of thiazide-induced hyponatraemia: time to reconsider electrolyte monitoring regimens after thiazide initiation?

AIMS

Hyponatraemia is one of the major adverse effects of thiazide and thiazide-like diuretics and the leading cause of drug-induced hyponatraemia requiring hospital admission. We sought to review and analyze all published cases of this important condition.

METHODS

Ovid Medline, Embase, Web of Science and PubMed electronic databases were searched to identify all relevant articles published before October 2013. A proportions meta-analysis was undertaken.

RESULTS

One hundred and two articles were identified of which 49 were single patient case reports. Meta-analysis showed that mean age was 75 (95% CI 73, 77) years, 79% were women (95% CI 74, 82) and mean body mass index was 25 (95% CI 20, 30) kg m⁻². Presentation with thiazide-induced hyponatraemia occurred a mean of 19 (95% CI 8, 30) days after starting treatment, with mean trough serum sodium concentration of 116 (95% CI 113, 120) mm and serum potassium of 3.3 (95% CI 3.0, 3.5) mm. Mean urinary sodium concentration was 64 mm (95% CI 47, 81). The most frequently reported drugs were hydrochlorothiazide, indapamide and bendroflumethiazide.

CONCLUSIONS

Patients with thiazide-induced hyponatraemia were characterized by advanced age, female gender, inappropriate saliuresis and mild hypokalaemia. Low BMI was not found to be a significant risk factor, despite previous suggestions. The time from thiazide initiation to presentation with hyponatraemia suggests that the recommended practice of performing a single investigation of serum biochemistry 7–14 days after thiazide initiation may be insufficient or suboptimal. Further larger and more systematic studies of thiazide-induced hyponatraemia are required.     

Activation of the renal Na+:Cl- cotransporter by angiotensin II is a WNK4-dependent process

Pseudohypoaldosteronism type II is a salt-sensitive form of hypertension with hyperkalemia in humans caused by mutations in the with-no-lysine kinase 4 (WNK4). Several studies have shown that WNK4 modulates the activity of the renal Na(+)Cl(-) cotransporter, NCC. Because the renal consequences of WNK4 carrying pseudoaldosteronism type II mutations resemble the response to intravascular volume depletion (promotion of salt reabsorption without K(+) secretion), a condition that is associated with high angiotensin II (AngII) levels, it has been proposed that AngII signaling might affect WNK4 modulation of the NCC. In Xenopus laevis oocytes, WNK4 is required for modulation of NCC activity by AngII. To demonstrate that WNK4 is required in the AngII-mediated regulation of NCC in vivo, we used a total WNK4-knockout mouse strain (WNK4(-/-)). WNK4 mRNA and protein expression were absent in WNK4(-/-) mice, which exhibited a mild Gitelman-like syndrome, with normal blood pressure, increased plasma renin activity, and reduced NCC expression and phosphorylation at T-58. Immunohistochemistry revealed normal morphology of the distal convoluted tubule with reduced NCC expression. Low-salt diet or infusion of AngII for 4 d induced phosphorylation of STE20/SPS1-related proline/alanine-rich kinase (SPAK) and of NCC at S-383 and T-58, respectively, in WNK4(+/+) but not WNK4(-/-) mice. Thus, the absence of WNK4 in vivo precludes NCC and SPAK phosphorylation promoted by a low-salt diet or AngII infusion, suggesting that AngII action on the NCC occurs via a WNK4-SPAK-dependent signaling pathway. Additionally, stimulation of aldosterone secretion by AngII, but not by a high-K(+) diet, was impaired in WNK4(-/-) mice.     

复方缬沙坦片的制备及体外溶出度测定

目的:研制缬沙坦和氢氯噻嗪的复方片。方法:选用交联聚维酮(PVPP)、微晶纤维素(MCC)、α-乳糖、硬脂酸镁为辅料与缬沙坦和氢氯噻嗪混匀后制片,采用正交法设计实验,考察不同处方制备的复方缬沙坦片在0.05 M pH6.8磷酸盐缓冲液中的溶出度,通过溶出度(主)、物料流动性(次)等指标对处方进行优化,确定最佳处方。结果:优化处方每片含缬沙坦80 mg、氢氯噻嗪12.5 mg、PVPP 6 mg、MCC 37.5 mg、硬脂酸镁4.5 mg、α-乳糖9.5 mg,其溶出度为88.74%。结论:自制片外表光洁美观,溶出度符合中国药典要求。     

Iatrogenic hypercalcemia due to vitamin D3 ointment (1,24(OH)2D3) combined with thiazide diuretics in a case of psoriasis

Tacalcitol is a synthetic vitamin D3 analogue developed for topical treatment of inflammatory skin diseases such as psoriasis. Hypercalcemia has not been previously reported during treatment with topical tacalcitol. We experienced a male patient with psoriasis and hypertension whose conditions were treated with tacalcitol ointment and thiazide, respectively, resulting in hypercalciuria and hypercalcemia. After initiation of topical vitamin D3 ointment (20 micro g/g of tacalcitol) 10 g/day for the skin lesions, both the serum level of calcium and urinary excretion of calcium increased gradually. On day 28 of the treatment, his serum calcium levels had reached 3.55 mmol/l, and his urinary calcium excretion had also increased from 0.008 g/day to 0.475 g/day. The tacalcitol treatment was terminated, seven days later, the serum calcium level had returned to the reference range without any specific treatment. The present case is the first report of hypercalcemia induced by vitamin D3 ointment and thiazide simultaneously.     

Thiazide Prophylaxis of Urolithiasis

ABSTRACT Fifty recurrent stone formers were included in a double-blind randomized study (median 3 years) performed in a Norwegian general practice to compare twice daily administration of 25 mg hydrochlorothiazide versus placebo. The number of patients with new stones was significantly higher in the placebo group than in the thiazide group (p=0.05, one-tailed test). If a new stone was formed, thiazide, but not placebo, had the effect of prolonging the stone-free interval (p≤0.01). The probability of not forming a new stone during the treatment period was 45% for the placebo group and 75% for the thiazide group. The thiazide effect seemed to be independent of urinary calcium, but was less beneficial in patients with hyperuricosuria. The placebo group also showed a substantial decrease in the expected number of new stones (p≤0.01), emphasizing the importance of an adequate control group.     

An unusual cause of abdominal pain: thiazide-related hypercalcemia in a patient with veiled hyperparathyroidism and thyroid papillary carcinoma

Hypercalcemia is an uncommon cause of abdominal pain and may be overlooked in the Emergency Department. In this case report, we describe the case of a 48-year-old woman with a prior history of urolithiasis who presented to the Emergency Department with diffuse abdominal pain. She had taken Trichlormethiazide 1 mg daily for her urolithiasis. She was diagnosed with thiazide-related hypercalcemia; hyperparathyroidism and thyroid papillary carcinoma were unveiled during her hospitalization. A thorough history and complete physical examination, paired with appropriate but judicious diagnostic testing, are essential to detecting these unusual causes of abdominal pain.     

Lithium toxicity

We report a case of severe lithium toxicity precipitated by a thiazide diuretic and compounded by an angiotensin converting enzyme inhibitor. There was severe vasodilatation refractory to noradrenaline.     

Relation Between Low Dose of Hydrochlorothiazide, Antihypertensive Effect and Adverse Effects

Thiazide diuretics are widely used in the drug treatment of hypertension but their dose-response curves for the antihypertensive and adverse metabolic effects differ. To characterize the lower end of the dose-response curve a double-blind, parallel group trial was performed as multicentre study in Scandinavia. One hundred and eleven patients with newly diagnosed or previously treated mild to moderate hypertension (untreated diastolic blood pressure of 95-115 mmHg after 4 weeks placebo) were randomly allocated to various doses of hydrochlorothiazide (3, 6, 12.5 or 25 mg) or placebo for 6 weeks. Blood pressure and biochemical variables (plasma renin activity, serum potassium, magnesium, urate, fasting glucose, total cholesterol, HDL-cholesterol, triglycerides and apolipoproteins A1 and B were measured. 12.5 mg hydrochlorothiazide had a borderline effect on blood pressure whilst 25 mg had a definite antihypertensive effect. Biochemical changes were seen in plasma renin activity, serum potassium and urate after the 12.5 and 25 mg dose. Three and 6 mg had no effect on blood pressure or metabolic parameters.     

EFFECTS OF ENALAPRIL AND HYDROCHLOROTHIAZIDE ON BLOOD PRESSURE, RENIN–ANGIOTENSIN SYSTEM, AND ATRIAL NATRIURETIC FACTOR IN ESSENTIAL HYPERTENSION: A DOUBLE BLIND FACTORIAL CROSS-OVER STUDY

The hypotensive and hormonal effects of the angiotensin converting enzyme (ACE) inhibitor enalapril (10 mg twice daily) were compared with those of hydrochlorothiazide (25 mg twice daily), with the two drugs in combination and with placebo in 21 patients with essential hypertension. For each patient there were four randomised double-blind treatment phases, each of four weeks' duration, which comprised a 2 times 2 factorial experiment.