PHARMACOKINETICS AND PHARMACODYNAMICS OF MIDAZOLAM GIVEN VIA CONTINUOUS INTRAVENOUS-INFUSION IN INTENSIVE-CARE UNITS

Critically ill patients often benefit from sedation to optimize their care and their ventilatory support. Ideally, incremental doses of a dr ug are administered to produce the desired level of sedation without t oxicity or overdose. Because metabolism and elimination of drugs are o ften altered in critically ill patients, knowledge of the pharmacokine tics of sedative hypnotics is essential to ensure their appropriate se lection and administration. Furthermore, the administration of sedativ es via continuous infusion minimizes fluctuations in drug concentratio ns and permits more consistent control of the patient's agitation and anxiety. Physician preference and the patient's individual requirement s and underlying diseases are the primary determinants for the selecti on of a given sedative. Benzodiazepines are the most commonly used sed atives in critical care. Midazolam is readily distinguished from other benzodiazepines because of its rapid onset and short duration of acti on, low incidence of thrombophlebitis and pain on injection, and minim al cardiovascular and respiratory effects. The physicochemical propert ies of midazolam allow for enhanced water solubility, which limits phy sicochemical incompatibilities. These properties make midazolam a valu able sedative that can be given via continuous intravenous infusion in the intensive care unit.