Effect of narcotic antagonists on the pupil diameter of nonaddicts

The pupillary effects of opioids

Morphine's miotic action on the pupil is an easily recognizable and quantifiable effect in man. The neural pathways responsible for regulating pupil size are reasonably well defined. Yet, the mechanisms behind this and related effects of opioids on the eye in humans and laboratory animals have just begun to be explored. In this review, we have attempted to organize the available information on pupillary actions of opioids, emphasizing the dynamic nature of the responses, their species specificity, possible mechanisms of action, and the recently discovered development of tolerance to these actions. Our current knowledge regarding differences among the opioids, the effects of endogenous opioid peptides and the role of the various opiate receptor subtypes in pupillary effects is also summarized.

Pupillography response to methadone challenge: aid to diagnosis of opioid dependence

Diagnostic pupillography, under blind conditions, produced constrictions greater than 0.75 mm in 25 opiod addicts and no change or dilation in 82 others. Placebo use produced no constrictions in 99 subjects. Methadone test dose pupillography provides significant information useful in diagnosing opioid dependence and is more acceptable to addicts than naloxone testing.

Pupillometric studies in the beagle dog

A method of measuring pupillary diameter in the dog using a Kowa RC-2 fundus camera, to which an eyepiece graticule had been fitted, is described. Pupil diameter was measured either directly by reading off from the calibrated graticule or from photographs. The pupillary diameters of 105 (53 male, 52 female) untreated English beagles aged between 8 and 32 months were measured under light intensities of 150-200 lux and 1000-1400 lux. Mydriatic and miotic pupillary diameters were measured in 62 male and 80 female dogs. Time-effect curves were plotted for two groups of 5 beagles receiving 75 mug/kg or 175 mug/kg atropine and 100 mug/kg or 300 mug/kg propantheline intravenously. The dose-effect curve for propantheline was found to be linear. A dose of 109 (97-121) mug/kg propantheline increased pupillary diameter by 3 mm, 20 min after administration. The time- and dose-effect curves, the significant sex differences and age dependency seen in this study indicate both a high degree of accuracy and the suitability of both of these methods for use in pharmacological and toxicological studies.