BARBITURATES AND ANALGESICS IN CALLIPHORA-VICINA LARVAE

Calliphora vicina larvae were reared on artificial foodstuffs spiked w ith a range of concentrations of aspirin (acetylsalicylic acid), sodiu m salicylate, paracetamol, sodium aminohippurate, amphetamine sulfate, and the barbiturates thiopentone, phenobarbitone, amylobarbitone, bar bitone, and brallobarbitone. Larvae were harvested at either day 6, 7, or 8 for analysis of drug content. Paracetamol, aspirin, amylobarbito ne, and thiopentone were not detected in larvae fed on foodstuff conta ining drug concentrations equivalent to those expected in skeletal mus cle from fatal human overdoses. Drug concentrations in larvae (express ed as larva: Foodstuff drug ratio) were 12-14% for phenobarbitone, 9-1 1% for sodium salicylate, 10% for aminohippurate, 18-19% for brallobar bitone, 41% for amphetamine, and 50-67% for barbitone. Amylobarbitone became detectable in larvae fed on higher drug concentrations (larva: Foodstuff drug ratio 2.6-21%). Higher levels of thiopentone and phenob arbitone were lethal to the larvae. Despite sharing similar basic stru ctures, related drugs were each handled very differently by the larvae . We found it impossible to predict, on the basis of chemical structur e, which drugs are likely to be detectable in Calliphora vicina larvae and in what ratio to the drug-spiked foodstuff. Drug concentrations i n larvae are significantly lower than in their food source and the abs ence of a drug from feeding larvae does not necessarily imply its abse nce from the food source.