[Influence of the intravenous nitroglycerin dose on the appearance of drug tolerance].
BACKGROUND
There are few studies on the influence of different doses of intravenous nitroglycerin (NTG) on the appearance of drug tolerance.


METHODS
A controlled clinical trial was performed in 40 patients admitted to an ICU with the diagnosis of acute myocardial infarction (AMI). The patients were divided into two groups: group A with a continuous perfusion of NTG at 2 mg/h, and group B with 4 mg/h. At 30 minutes of the infusion, NTG was exchanged for a placebo in half of the patients of each group (subgroups A1 and B1) with the remaining patients continuing with NTG for 24 h (A2 and B2). The hemodynamic variables studied were central venous pressure (CVP), pulmonary capillary pressure (PCP), mean pulmonary artery pressure (PAP) and mean blood pressure (BP).


RESULTS
The patients in group A showed a decrease in the hemodynamic effects in all the variables studied. At 24 h of infusion no differences were observed with respect to the previous NTG values for CVP and PCP, with significant differences being maintained for PAP and BP. In group B the hemodynamic effect was maintained for all the variables during the 24 hours studied.


CONCLUSIONS
In patients with acute myocardial infarction, the dosis of nitroglycerin administered was found to have a determined influence in the appearance of drug tolerance with this fact being more evident on evaluation of the effect of nitroglycerin on the venous system.
Barranco
F
F
Servicios de Medicina Intensiva, Hospital Universitario San Cecilio, Granada.
Lesmes
A
A
Irles
J
J
Peñas
L
L
Schiaffino
S
S
Ballesteros
J
J
Pomares
J
J
D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D002496:Central Venous Pressure / Q000187:drug effects; D004361:Drug Tolerance; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000503:physiopathology; D005996:Nitroglycerin / Q000008:administration & dosage* / Q000494:pharmacology; D010919:Placebos; D011651:Pulmonary Artery / Q000187:drug effects; D011669:Pulmonary Wedge Pressure; D013997:Time Factors
D010919:Placebos; D005996:Nitroglycerin
Influencia de la dosis de nitroglicerina intravenosa en la aparición de tolerancia farmacológica.