Methylene blue, a nitric oxide inhibitor, prevents haemodialysis hypotension.
BACKGROUND
Plasma nitric oxide (NO) levels have been found to be high in haemodialysis (HD) patients, especially in those prone to hypotension in dialysis. The aim of the study was to prevent dialysis hypotension episodes by i.v. administration of methylene blue (MB), an inhibitor of NO activity and/or production.


METHODS
MB was given i.v. in 18 stable HD patients with hypotensive episodes during almost every dialysis, in 18 HD patients without hypotension during dialyses, and in five healthy controls. MB was given as a bolus of 1 mg/kg bodyweight followed by a constant infusion of 0.1 mg/kg bodyweight lasting 210 min until the end of the dialysis session and only as a bolus on a non-dialysis day. Systolic and diastolic blood pressures (BP) were measured at 10-min intervals during HD sessions with or without MB and on a non-dialysis day with MB.


RESULTS
In hypotension-prone patients, MB completely prevented the hypotension during dialysis and increased both systolic and diastolic BP on non-dialysis days. In normotensive patients, MB increased BP during the first hour of dialysis and for 90 min on the non-dialysis day. The BP in the healthy controls remained unchanged. Plasma and platelet NO(2)+NO(3) (stable metabolites of NO) levels were determined. The NO(2)+NO(3) generation rate in the first post-dialysis day was calculated. The plasma and platelet NO(2)+NO(3) were higher in the hypotensive group than in the normotensive dialysis group. The generation rate of nitrates was higher (P<0.01) in the hypotensive group (1.21+/-0.13 micromol/min and 0.74+/-0.16 after MB) than in the normotensive patients (0.61+/-0.11 micromol/ min and 0.27+/-0.14 after MB). No side-effects were recorded.


CONCLUSIONS
MB is an efficient therapy in the prevention of dialysis hypotension.
Peer
G
G
Department of Nephrology, Ichilov Hospital, Tel Aviv Medical Center, Tel Aviv, Israel.
Itzhakov
E
E
Wollman
Y
Y
Chernihovsky
T
T
Grosskopf
I
I
Segev
D
D
Silverberg
D
D
Blum
M
M
Schwartz
D
D
Iaina
A
A
D000328:Adult; D000368:Aged; D001792:Blood Platelets / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects*; D003971:Diastole / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D007022:Hypotension / Q000209:etiology* / Q000517:prevention & control*; D007676:Kidney Failure, Chronic / Q000628:therapy*; D008751:Methylene Blue / Q000494:pharmacology / Q000627:therapeutic use*; D008875:Middle Aged; D009566:Nitrates / Q000097:blood; D009569:Nitric Oxide / Q000037:antagonists & inhibitors; D009573:Nitrites / Q000097:blood; D006435:Renal Dialysis / Q000009:adverse effects*; D013599:Systole / Q000187:drug effects; D013997:Time Factors
D004791:Enzyme Inhibitors; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; D008751:Methylene Blue