Acute renal failure, drug metabolism

Baliga, R., Ueda, N., Walker, P. D., Shah, S. V. (1999 Nov). Oxidant mechanisms in toxic acute renal failure. Drug Metabolism Reviews, 31 4), 971-997. 

The renal clearance can be under estimated in the case of renal drug metabolism. The total drug clearance depends on bioavailability. Therefore, the most reliable estimate for the fraction eliminated by the renal route (fren) is given by the normal clearance (Clnorm) and drug clearance in case of acute and/ or chronic renal failure (Clfail), or from half-lives (Tl/2norm) and (Tl/2fail). 

Procainamide INa (primary) and IKr (secondary) blockade Slows conduction velocity and pacemaker rate prolongs action potential duration and dissociates from INa channel with intermediate kinetics direct depressant effects on sinoatrial (SA) and atrioventricular (AV) nodes Most atrial and ventricular arrhythmias drug of second choice for most sustained ventricular arrhythmias associated with acute myocardial infarction Oral, IV, IM eliminated by hepatic metabolism to /V-acetylprocainamide (NAPA see text) and renal elimination NAPA implicated in torsade de pointes in patients with renal failure Toxicity Hypotension long-term therapy produces reversible lupus-related symptoms... 

Metformin is contraindicated in patients with heart failure, renal disease, hypersensitivity to metformin, and acute or chronic metabolic acidosis, including ketoacidosis. The drug is also contraindicated in patients older than 80 years and during pregnancy (Pregnancy Category B) and lactation. 

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