Decreased serum albumin, due to illness or decreased
protein synthesis (due to ageing), potentiates the
response to drugs that bind to albumin by increasing the
free-drug fraction in the acute condition. Therefore, drug
levels or response correlation could be altered and this
needs to be considered when interpreting drug levels
especially during long-term usage. An elevated level of
the acute phase reactant α1
-acid glycoprotein, due to
ageing or disease, increases the binding of basic drugs,
such as lignocaine, which in turn decreases the drug
response.