Nitroglycerin reductase

Erythrityl is readily absorbed from the GI tract. It undergoes extensive first-pass metaboHsm ia the Hver by glutathione organic nitrate reductase. Time to onset of effect is 5—10 min by subHngual adrninistration and 20—30 min when swallowed. The duration of effects for the two routes ate up to 3 and 6 h, respectively. Adverse effects are similar to those described for nitroglycerin (99). 

Blehert DS, KL Knoke, BG Fox, GIT Cambliss (1997) Regioselectivity of nitroglycerine denitration by flavoprotein nitroester reductases purified from two Pseudomonas species. J Bacterial 179 6912-6920. 

D Rifampin significantly reduces the plasma concentrations of the calcium channel blockers verapamil, diltiazem, and nifedipine. Diltiazem is a substrate of Gi P3A4 and rifampin is an inducer of CYP3A4. Rifampin does not interact with metoprolol, aspirin, pravastatin, or nitroglycerin. However, if the patient had been on another HMG-CoA reductase inhibitor such as atorvastatin, lova-statin, or simvastatin instead of pravastatin, rifampin would have reduced the plasma concentrations of these agents since they are also metabolized via CYP3A4. 

Biotransformations of nitroglycerin, (a) Normal mechanism of aldehyde reductase (b) production of nitrite by mitochondrial aldehyde dehydrogenase. 

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