A fatal case of amlodipine poisoning.

A fatal case attributed to amlodipine intoxication is presented. The deceased was a 15-year-old girl who allegedly ingested 14 10-mg Istin tablets. Amlodipine concentration in peripheral blood was determined (2.7 mg/L) and was compared with published therapeutic and toxic data for amlodipine and some other dihydropyridine calcium channel-blocking agents. Amlodipine concentrations in liver, blood, and stomach contents were also determined.

Novel solid-phase extraction strategy for the isolation of basic drugs from whole blood. Preliminary study using commercially available extraction cartridges.

A novel strategy for the solid-phase extraction of basic drugs has been developed using commercial extraction cartridges. The procedure involves the sequential application of very different isolation mechanisms, viz. hydrophobic extraction on non-porous carbon followed by ionic extraction on a strong cation exchanger. This approach to extraction achieves both high recoveries and clean extracts when analysed by GC-MS. The potential for automation has been demonstrated using commercial sample preparation equipment.

Effect of using alcoholic and non-alcoholic skin cleansing swabs when sampling blood for alcohol estimation using gas chromatography.

A study was carried out using 20 volunteers in whom venepuncture through the skin soaked in either ethyl or isopropyl alcohol was performed. A non-alcoholic cetrimide/chlorhexidine swab was used as a control. All subjects were initially alcohol free. Ethyl alcohol was detected in only one blood sample and the level was found to be only 0.4 mg% (roughly the limit of detection of the assay). A slightly higher level of isopropyl alcohol (3 mg%) was found in one of the blood samples. Alcohol estimation was carried out by head-space gas chromatography using a pair of instruments each fitted with a column exhibiting different retention characteristics. The system was similar to that used by other UK Forensic Science Laboratories where accurate, definitive results are a necessity. It was concluded that under very testing conditions only minute ethanol interference is produced by using alcohol-based skin cleansing swabs. This minimal interference is unlikely to affect clinical sample results, and even in a forensic situation the inadvertent use of alcohol-based swabs is unlikely to lead to a miscarriage of justice.

Drugs and the impaired driver in Northern Ireland: an analytical survey.

The techniques used to analyse 212 "under-the-limit" drink-driving blood and urine specimens for drugs during a 3-year period (1982-85) in Northern Ireland are described. In all of these specimens (representing 15% of all below-limit cases) either the police surgeon who carried out the clinical examination, or the police, strongly suspected that drugs may have been a contributory factor in driving impairment, considering the lower than expected alcohol concentration. Thirty-eight (18%) samples were found to contain significant drug(s). Benzodiazepines were the most frequently encountered group of drugs (87% of all positive cases) with diazepam being that most frequently encountered (18 cases). The analytical procedures were radioimmunoassay, gas chromatography using nitrogen selective and electron capture detection along with high performance liquid chromatography (HPLC) using ultra-violet detection. Drugs and their metabolites were identified using a mixture of these techniques along with GC/MS where possible. The usefulness of HPLC coupled with a rapid-scanning diode-array spectrophotometer is also demonstrated, the technique being particularly useful in the analysis of some of the more "difficult" benzodiazepines (e.g. lorazepam, temazepam, nitrazepam) not directly amenable to gas chromatography without derivatisation.