Of all the physiological conditions that may reap havoc on drug metabolism,?

Question

what ypes of drug dysfunction may be seen with a person who is in renal failure?

Answer 1

In general, renal failure affects drugs (or their metabolites) which are excreted by the kidneys. Not all drugs are, but many of them have at least some portion pass out through the urine. Complications can take several forms:

1. The active drug (or active metabolite) is excreted by the kidney. In renal failure, this causes a dose to stick around longer than it should or even be higher than it should. Doses of drugs (especially chronic use drugs) need to have their doses decreased.

2. The drug or a metabolite of the drug may be toxic. In renal failure, this drastically increases the chance for certain toxicities to develop. Doses need to be decreased or administered less frequently.

3. The drug directly affects the kidney, worsening renal failure. This causes increased chance for acute renal failure (especially in chronic renal failure patients). This also leads to a build up of toxic compounds that would otherwise be normally excreted by the kidneys. Again, doses must be adjusted, if possible.

Often, when renal failure gets really bad and a drug *must* be given (cancer, etc.), dialysis is initiated, even though the person may not normally need it. This may mitigate some of the effects.

In patients with renal failure, it's extremely important to keep reminding your doctors whenever a new prescription is written and always mention it to your pharmacist so they can double check. Every time! This is a situation in which a lot of medication errors can be avoided.