Interspecies scaling of inhalational anesthetic potency minimum alveolar concentration (MAC): application of a correction factor for the prediction of MAC in humans.
The objective of this study was to predict minimum alveolar concentration (MAC) of inhalational anesthetics in humans from animal data. The MAC of 10 anesthetics was obtained from the literature. At least three animal species (excluding humans) were used in the scaling. Interspecies scaling of MAC was performed in two ways: (1) using the traditional allometric approach, the MAC of each drug was plotted against the body weight of the species on a log-log scale, and MAC in humans was predicted from the resultant equation; and (2) MAC in each species was multiplied by a correction factor obtained by adjusting the lung weight of the species based on per kg body weight. The product of the correction factor and the MAC was then plotted against body weight as described in the traditional approach. Predicted MAC values in humans from animal data using simple allometry produced comparatively more error than the prediction made by incorporating the correction factor into the scaling. The results of this study indicate that MAC may not be predicted in humans from animal data using simple allometry; however, applying a correction factor may significantly improve the prediction of MAC in humans from animal data.
Mahmood
I
I
Office of Clinical Pharmacology and Biopharmaceutics (HFD-860), Division of Pharmaceutical Evaluation I, Food & Drug Administration, Rockville, MD 20852, USA. Mahomoodi@ccder.fda.gov
D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000818:Animals; D001835:Body Weight; D004285:Dogs; D004353:Drug Evaluation, Preclinical; D000882:Haplorhini; D008168:Lung / Q000033:anatomy & histology*; D051379:Mice; D023421:Models, Animal; D009929:Organ Size; D011237:Predictive Value of Tests; D011650:Pulmonary Alveoli / Q000378:metabolism*; D011817:Rabbits; D051381:Rats; D013045:Species Specificity
D018685:Anesthetics, Inhalation