Fosinopril dosage

Fosinopril and spirapril - the only drugs with compensatory dual routes of elimination - do not require dosage adjustment in patients with reduced renal function, as do other ACE-inhibitors. 

With the notable exceptions of fosinopril and spirapril (which display balanced elimination by the liver and kidneys), ACE inhibitors are cleared predominantly by the kidneys. Therefore, impaired renal function significantly diminishes the plasma clearance of most ACE inhibitors, and dosages of these drugs should be reduced in patients with renal impairment. Elevated plasma renin activity (PRA) renders patients hyperresponsive to ACE inhibitor-induced hypotension, and initial dosages of all ACE inhibitors should be reduced in patients with high plasma levels of renin (e.g., patients with heart failure, and salt-depleted patients). 

Using fosinopril sodium as the example, one can see evidence of such a relaxation transition. This was not observed in the final dosage form, but it probably would have occurred if the metastable form B had been chosen for development instead of the stable form A. In one study, a sample of form B was characterized by solid-state NMR, and then again after three months of storage at ambient laboratory conditions. As is evident from the data presented in Figs. 34a and b, the... 

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