Читать книгу Clinical Pharmacology and Therapeutics - Группа авторов - Страница 84

With ageing, there is a fall in both renal blood flow and renal function and dose reduction should be considered if prescribing a renal‐excreted drug in the elderly. Glomerular filtration falls by approximately 30% by the age of 65 years. Digoxin and the aminoglycoside antibiotics are excreted mainly by glomerular filtration and these will tend to accumulate in the elderly if the dose is not reduced.

Renal tubular function also declines and drugs that undergo active tubular secretion (in routine practice mainly penicillin) have a marked reduction in clearance, but this is of limited clinical relevance. Often acutely unwell elderly patients are dehydrated, further compromising renal function. In these circumstances (i.e. acute kidney injury), potentially nephrotoxic drugs should be withheld.