Inadvertently high dialysate magnesium causing weakness and nausea in hemodialysis patients.

As maintenance hemodialysis patients are exposed to large quantities of dialysis water, any contamination of it might be reflected in plasma levels. We present a series of cases due to such a contamination. Six maintenance hemodialysis patients dialyzing at the same peripheral hemodialysis facility presented to us over a short period of time with symptoms mimicking inadequate dialysis. Their blood urea and creatinine levels were not very high, but all the patients had hypermagnesemia [serum Mg levels = 1.8 (±0.3) mmol/L]. Except for one patient who had cardiac arrest at presentation, all patients improved after undergoing hemodialysis at our center [serum Mg at discharge = 0.86 (±0.01) mmol/L]. The origin of hypermagnesemia was traced to dialysis water contamination with magnesium due to inadequate maintenance of the water treatment system. Corrective measures improved the quality of water, and no further cases were reported from that center. Proper maintenance and periodic checks of the quality of water are central to the outcomes of maintenance hemodialysis patients.

Efficacy of Low-Dose Chlorthalidone and Hydrochlorothiazide as Assessed by 24-h Ambulatory Blood Pressure Monitoring.

BACKGROUND: Thiazide and thiazide-like diuretic agents are being increasingly used at lower doses. Hydrochlorothiazide (HCTZ) in the 12.5-mg dose remains the most commonly prescribed antihypertensive agent in the United States. OBJECTIVES: This study compared chlorthalidone, 6.25 mg daily, with HCTZ, 12.5 mg daily, by 24-h ambulatory blood pressure (ABP) monitoring and evaluated efficacy. Because HCTZ has been perceived as a short-acting drug, a third comparison with an extended-release formulation (HCTZ-controlled release [CR]) was added. METHODS: This 12-week comparative, double-blind, outpatient study randomized 54 patients with stage 1 hypertension to receive either chlorthalidone, 6.25 mg, (n = 16); HCTZ 12.5 mg (n = 18); or HCTZ-CR 12.5 mg (n = 20). ABP monitoring was performed at baseline and after 4 and 12 weeks of therapy. RESULTS: All 3 treatments significantly (p < 0.01) lowered office BP at weeks 4 and 12 from baseline. At weeks 4 and 12, significant reductions in systolic and diastolic 24-h ambulatory and nighttime BP (p < 0.01) were observed with chlorthalidone but not with HCTZ. At weeks 4 (p = 0.015) and 12 (p = 0.020), nighttime systolic ABP was significantly lower in the chlorthalidone group than in the the HCTZ group. With HCTZ therapy, sustained hypertension was converted into masked hypertension. In contrast to the HCTZ group, the HCTZ-CR group also showed a significant (p < 0.01) reduction in 24-h ABP. All 3 treatments were generally safe and well tolerated. CONCLUSIONS: Treatment with low-dose chlorthalidone, 6.25 mg daily, significantly reduced mean 24-h ABP as well as daytime and nighttime BP. Due to its short duration of action, no significant 24-h ABP reduction was seen with HCTZ, 12.5 mg daily, which merely converted sustained hypertension into masked hypertension. Thus, low-dose chlorthalidone, 6.25 mg, could be used as monotherapy for treatment of essential hypertension, whereas low-dose HCTZ monotherapy is not an appropriate antihypertensive drug. (Comparative Evaluation of Safety and Efficacy of Hydrochlorothiazide CR with Hydrochlorothiazide and Chlorthalidone in Patients With Stage I Essential Hypertension; CTRI/2013/07/003793).