DRUG ANALYSIS IN FLY LARVAE

We reared larvae of Calliphora vicina on human skeletal muscle obtaine d from cases of suicidal overdose with co-proxamol (propoxyphene and a cetaminophen) and amitriptyline. After 4 days, third-instar larvae wer e either transferred to drug-free muscle or continued to feed on drug- laden muscle for a further 2 days prior to harvesting. Amitriptyline a nd nortriptyline were detected in both groups of larvae, but propoxyph ene was only in those fed continuously on drug-laden muscle, and aceta minophen was in neither. Drug concentrations in muscle food source wer e amitriptyline 0.48 mug/g, nortriptyline 0.38 mug/g, propoxyphene 0.9 9 mug/g, and acetaminophen 14.13 mug/g. For triplicate rearings, the m ean ratios of drug concentrations in larvae to food source were amitri ptyline, 0.56; nortriptyline, 0.5; and propoxyphene, 0.06. In triplica te rearings, no drug or metabolite was detected in puparia, puparial c ases, or imagos. We conclude that the absence of a drug in maggots is not necessarily an indication that the drug was not present in signifi cant concentrations in the food source. The malpighian tubules and the ''nephrocytes'' of fly larvae appear capable of eliminating different drugs with varying efficiency.