Mivacurium in special patient groups.

In special patient groups, drug response may be different from that in the healthy adult patient. Mivacurium dose requirements vary with age, and children require larger doses to obtain any given degree of block, but the elderly often require smaller doses. However, the dose requirements of the neonate do not necessarily differ greatly from those of the adult. There is a relationship between the duration of action of a bolus dose – as well as infusion requirements to maintain block – and the plasma cholinesterase activity. Patients with renal disease may have a decreased cholinesterase activity and may require smaller doses of mivacurium. Patients with severe liver disease may have a marked decrease in cholinesterase activity, and in these patients a substantially smaller dose of the drug may be needed to obtain and maintain any given degree of block. If the variation in dose requirements is kept in mind and the degree of block appropriately monitored, mivacurium may be used with safety in special patient groups, such as children, the elderly, or those with renal or hepatic impairment.