Metronidazole: The new cocaine adulterant in Uruguay?

Abstract

In the first months of this year, more than 500 kg of cocaine were seized in the country. Although in the recent years the use of cocaine has been stable on regard to levels of consumption, in the last 12 months it has reached 2% of the population. Toxic complications secondary to consumption depend on the concentration of cocaine as well as the presence of adulterants. Although caffeine, phenacetin, aminopyrine and levamisole have mostly been found as cocaine adulterants in Uruguay, the range is quite wide when other drugs such as Ibuprofen or Ketoprofen are considered. If we also consider polydrug use and the recent seizures of drugs sold as “2-c” or pink cocaine whose content varies between mixtures of ketamine, MDMA or MDA, cocaine, tramadol and caffeine, it is not surprising to find associated cases of intoxication and submission. In this study we present the findings of the determination of drugs of submission in human urine from the Center for Toxicological Information and Advice (CIAT). The requested assay was the determination of submission drugs in a urine sample from a female patient who reported possible sexual abuse and exposure to submission drugs. Considering the clinical history, two liquid-liquid extraction techniques were performed, with different pH conditions and extraction solvents, and then analyzed by GC/MSD: Agilent 6890 Gas Chromatograph coupled to Agilent 5973 Mass Detector. In addition, an ELISA immunoassay was carried out for the determination of cocaine metabolites. The exhaustive analysis by GC/MS allowed to determine the presence of: ibuprofen, ketoprofen and its metabolites, ketorolac, metronidazole and its hydroxy metabolite and traces of cocaine. The presence of benzoylecgonine, the main metabolite of cocaine, was found by ELISA immunoassay. Although the initial approach was to search for submissive drugs due to clinical history, the presence of GHB, GBL, THF, 1,4-butanediol, Scopolamine, Ketamine and Benzodiazepines could not be detected by GC/MS. Considering the finding of cocaine and the rest of the substances, as well as an oral information on seizures, we started to considering that we are probably facing a new cocaine adulterant in the country: metronidazole. Although this drug is used to treat human infections and is generally well tolerated with minimal side effects, there are neurological complications of metronidazole treatment. Among these complications are confusion to decreased level of consciousness and even coma, and they could be use in cases of submission. To summarize, we cannot rule out that there has been exposure to submission drugs due to the effects that metronidazole can produce. In addition, considering the recent findings in the seizures of cocaine, we cannot dismiss that we are dealing with a new cocaine adulterant. The new findings associated with drugs, local mixtures and their forms of consumption, including adulterants, are extremely relevant for poison control centers as well as public policies. Also, this information allows the country to take preventive measures and generate useful information for public health.