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I read with interest the review article on the management of acute decompensated heart failure by Larry Allen and Christopher O'Connor.1 The authors commented that nitroglycerin is probably underused in patients presenting with acute decompensated heart failure. However, in Table 1, in which they recommend switching from sublingual to intravenous delivery of nitroglycerin, the dose they suggest for initiating intravenous delivery seems low. A sublingual regimen of 0.4 mg every 5 minutes (the typical dose at my institution) is mathematically equivalent to 80 μg/min.
The bioavailability of sublingual nitroglycerin is cited in a 1998 study as 38%,2 but it can be highly variable.3 In many patients the tablets appear to be absorbed quickly and completely, but not infrequently one finds a tablet that remains undissolved after 5 minutes. In the latter circumstance, a lower dose of intravenous nitroglycerin, such as that recommended by the authors, would be suitable. In patients with marked hypertension not responding to completely dissolved sublingual nitroglycerin, a higher starting dose may be more appropriate.
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Competing interests: None declared