Pharmacokinetic Considerations in Geriatric Medication

Aging have an impact on the pharmacokinetic and pharmacodynamic characteristics of drugs, resulting in clinically relevant safety and efficacy consequences. There appear to be a rise in gastrointestinal (GI) problems with age, and certain slight variations in the GI tract have been noted. Nevertheless, insufficient studies have been done on the impact of aging on the expression and activity of these GI transporters. Aging is associated with some reduction in first-pass metabolism that might be due to a decrease in liver mass and perfusion. Some medications with considerable first-pass metabolism, can have markedly enhanced bioavailability and, as a consequence bioavailability. Other high clearance (CL) medications have identical bioavailability in both young and old individuals. However, at the other hand, the first-pass activation of some prodrugs, may be slowed or decreased, leading to a reduction in bioavailability. Some drugs may have a low bioavailability when taken orally, benefitted from transdermal administration. There are still no specific age-related liver ailments, routine clinical tests of liver function do not vary substantially with age, the course, and outcome of some liver diseases can be affected by age. The characteristic of high or low extraction of a drug by the liver has been attributed to whether the metabolic clearance (CL) of a drug falls or remains unchanged with age. Reduction in renal function in elderly subjects, particularly glomerular filtration rate, affects the clearance of many drugs such as water-soluble antibiotics and nonsteroidal anti-inflammatory drugs. The therapeutic significance of these declines in renal excretion is governed by the drug's expected toxicity. Many drugs show their effects specially in old age patients in different manner and depend on age related factors. It must take appropriate precautions for administering of different drugs to the old age patients.