DIHYDROPYRIDINE TYPE CALCIUM-CHANNEL BLOCKER-INDUCED TURBID DIALYSATEIN PATIENTS UNDERGOING PERITONEAL-DIALYSIS

We previously reported that manidipine, a new dihydropyridine type cal cium channel blocker, produced chylous peritoneal dialysate being visu ally indistinguishable from infective peritonitis in 5 patients underg oing continuous ambulatory peritoneal dialysis (CAPD) [Yoshimoto et al . 1993]. To study whether such an adverse drug reaction would also be elicited by other commonly prescribed calcium channel blockers in CARD patients, we have conducted postal inquiry to 15 collaborating hospit als and an institutional survey in International Medical Center of Jap an as to the possible occurrence of calcium channel blocker-associated non-infective, turbid peritoneal dialysate in CAPD patients. Our diag nostic criteria for drug-induced turbidity of dialysate as a) it devel oped within 48 h after the administration of a newly introduced calciu m channel blocker to the therapeutic regimen, b) absence of clinical s ymptoms of peritoneal inflammation (i. e., pyrexia, abdominal pain, na usea or vomiting), c) the fluid containing normal leukocyte counts and being negative for bacterial and fungal culture of the fluid, and d) it disappeared shortly after the withdrawal of the assumed causative a gent. Results showed that 19 out of 251 CAPD patients given one of the calcium channel blockers developed non-infective turbid peritoneal di alysis that fulfilled all the above criteria. Four calcium channel blo ckers were suspected to be associated with the events: benidipine [2 o ut of 2 (100%) patients given the drug], manidipine [15 out of 36 (42% ) patients], nisoldipine [1 out of 11 (9%) patients] and nifedipine [1 out of 159 (0.6%)] in descending order of frequency. None of the pati ents who received nicardipine, nilvadipine, nitrendipine, barnidipine and diltiazem (25, 7, 2, 1 and 8 patients, respectively) exhibited tur bid dialysate. In conclusion, we consider that certain dihydropyridine type calcium channel blockers would cause turbid peritoneal dialysate being similar to that observed in patients developing infective perit onitis. To avoid unnecessary antibiotic therapy the possibility of thi s adverse reaction should be ruled out whenever a CAPD patient receivi ng a dihydropyridine type calcium channel blocker develops turbid dial ysate.