Assessment of the drug interaction between intravenous nitroglycerin and heparin.
OBJECTIVE
To assess whether a clinically significant interaction occurs between heparin and nitroglycerin (NTG).


METHODS
Activated partial thromboplastin time (APTT) was measured in patients with unstable angina who were stabilized on intravenous NTG and heparin just prior to weaning the NTG infusion, and one and four hours after stopping the NTG.


RESULTS
In 22 heparin-treated patients (20 men, 2 women; aged 56.7 +/- 10 years; weight 79.5 +/- 15 kg), the APTT ratio was inversely related to the dose of NTG (slope = -0.003; p < 0.05). However, there were no significant differences between the APTT values measured before and after discontinuation of NTG (p = 0.8511).


CONCLUSIONS
Our study demonstrates a clinically insignificant interaction between NTG and heparin at NTG doses commonly used in patients.
Gonzalez
E R
ER
Department of Pharmacy and Pharmaceutics, School of Pharmacy, Virginia Commonwealth University, Richmond.
Jones
H D
HD
Graham
S
S
Elswick
R K
RK
D000368:Aged; D000789:Angina, Unstable / Q000097:blood / Q000188:drug therapy; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D005260:Female; D006493:Heparin / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage / Q000494:pharmacology*; D010314:Partial Thromboplastin Time
D006493:Heparin; D005996:Nitroglycerin