Detection of narcotic use. Comparison of the nalorphine (pupil) test with chemical tests.

The nalorphine (pupil) test for narcotic abuse is widely used in California. It is based on the ability of nalorphine to produce mydriasis in subjects who have recently taken morphine-like drugs and to produce miosis in others. The test will usually detect as little as 15 mg of morphine or comparable doses of other narcotics for several hours except in special circumstances. It is even more reliable for detection of chronic use of narcotics. A simple card pupillometer is adequate for measuring changes in pupil size resulting from nalorphine. Analysis for narcotics in urine by thin layer chromatography is also used, either alone or in conjunction with the pupil test, to detect drug abuse. In one study which included many urine speciments from subjects who had negative pupil tests the correlation between the pupil test and urinalysis was good (85 percent). When urinalysis was used to confirm suspicion of drug use resulting from a positive or equivocal pupil test, inter-method agreement dropped to about 50 percent for various reasons. Even so, use of the pupil test for screening and urinalysis for confirmation provides a satisfactory program for detection of narcotic abuse.