Pharmacokinetics and Pharmacodynamics of Edrophonium in Elderly Surgical Patients

Abstract

The effect of age (over 70 yr) on the pharmacokinetics and pharmacodynamics of edrophonium was evaluated in seven patients aged 76-87 yr and in seven patients aged 27-57 yr. When elderly patients were compared with younger controls, the elderly exhibited a statistically significant decreased plasma clearance (5.9 +/- 2 versus 12.1 +/- 4 mL.kg-1.min-1) and a prolonged elimination half-life (84.2 +/- 17 versus 56.6 +/- 16 min). Pharmacodynamically, a higher concentration of edrophonium is required in elderly patients to produce the same effect as in the younger controls. This observation may be explained in part by changes in neuromuscular transmission that are a function of the aging process. In addition, even though plasma concentrations were significantly greater at every sampling point in the elderly than the younger group, there was no difference between either the maximum duration or the total duration of action of edrophonium in the two groups. The maximum duration of action of edrophonium in both groups was very brief (1.3-2.2 min). These results contrast with a previous study of the anticholinesterases neostigmine and pyridostigmine, in which the action of these drugs was significantly prolonged in elderly patients. Explanations for the observed differences between edrophonium and other anticholinesterases may relate to differences in chemical structure and the possibility that edrophonium produces antagonism of neuromuscular blockade by a different mechanism than neostigmine or pyridostigmine.

Perioperative Management of Elderly patients (PriME): recommendations from an Italian intersociety consensus

“…The duration of action of the cholinesterase inhibitors neostigmine and pyridostigmine is prolonged in aged patients [ 116 , 117 ], whereas this is not true for edrophonium [ 118 ]. Hence, neostigmine and pyridostigmine are preferable to edrophonium for reversal of neuromuscular blockade in older patients, because their prolonged duration of action can counteract age-related increases in the duration of action of NMBAs.…”

Pharmacodynamic behaviour of rocuronium in the elderly

“…14 Similar findings were given in a preliminary report of the pharmacokinetic behaviour of rocuronium. 29 The most likely reason for the prolonged duration in the elderly is a decrease in renal and hepatic perfusion associated with aging.…”