Introduction
Continuous exposure to nitrates is associated with tachyphylaxis. This study compares the effects and tolerance during intravenous treatment with nitroglycerin and nicorandil over a 48-hour period.
Methods
Twenty patients with congestive heart failure and pulmonary capillary wedge pressure (PCWP) ≥18 mmHg were randomly assigned to nitroglycerin or nicorandil intravenous infusions. Doses were titrated to obtain a reduction of PCWP of at least 30% at 6 hours and then maintained for 48 hours.
Results
There was no statistical difference between the groups in terms of age, sex, and NYHA grade. The pretreatment PCWP for nitroglycerin was 25.7 mmHg, decreasing to 18.4 mmHg at 6 hours. The values for nicorandil were 25.4 mmHg and 17.3 mmHg, respectively. There was no statistical difference between the two groups (P = 0.79 pretreatment and 0.23 at 6 hours). The mean PCWP values for 24 hours were 19.7 and 17.4, respectively, which was statistically significant (P = 0.036). Similarly, the values for 48 hours were 20.6 and 17.9, which was significant (P = 0.026) (see Table 1).
Table 1.
PCWP values before and after treatment
| Variable | Nitroglycerin | Nicorandil |
|---|---|---|
| Number | 10 (8/2) | 10 (7/3) |
| Age | 49.9 | 51.4 |
| Pretreatment | 25.7 | 25.4 |
| 6 hours | 18.4 | 17.3 |
| 24 hours | 19.7 | 17.4 |
| 48 hours | 20.6 | 17.9 |
Conclusions
Intravenous nicorandil administration gives similar reductions in PCWP compared with nitroglycerin with significantly less haemodynamic tolerance over a 48-hour period compared with nitroglycerin. This might represent a clinical advantage of nicorandil in the short-term treatment of patients with congestive heart failure.
References
- Tsutamoto T, Kinoshita M, Nakae I. et al. Absence of hemodynamic tolerance to nicorandil in patients with severe congestive heart failure. Am Heart J. 1994;127(4 Pt 1):866–873. doi: 10.1016/0002-8703(94)90555-X. [DOI] [PubMed] [Google Scholar]