What's being used to spike your drink? Alleged spiked drink cases in inner city London

To determine the incidence and character of drink spiking in an urban population of patients within the UK presenting to an emergency department concerned they had consumed a deliberately contaminated drink.

Prospective case series determining the presence and quantity of sedative and illicit drugs, and ethanol in biological samples (blood and urine) obtained from consenting patients >18 years of age presenting to a large inner city London emergency department alleging they had consumed a spiked drink within the previous 12 h.

Biological samples were obtained from 67 (blood) and 75 (urine) of 78 study participants. 82% of participants were female, mean age 24 years. Mean time from alleged exposure to biological sampling was 5.9 h (range 1-12 h). Ethanol was detected in 89.7% of participants. Mean serum ethanol concentration was 1.65 g/l (range 0.04-3.1 g/l); 60% of participants had a serum ethanol concentration associated with significant intoxication (>1.5 g/l). Illicit drugs were detected in 12 (15%) participants; 7 denied intentional exposure (3 methylenedioxymethamphetamine, 3 cannabis, 1 gamma-hydroxybutyrate). Medicinal drugs were detected in 13 participants; only 1 exposure was unexplained (benzodiazepine). Overall illicit or medicinal drugs of unexplained origin were detected in 8 (10%) participants. Unexplained sedative drug exposure was detected in only 2 (3%) participants.

Use of sedative drugs to spike drinks may not be as common as reported in the mainstream media. A large number of study participants had serum ethanol concentrations associated with significant intoxication; the source (personal over-consumption or deliberate drink spiking) is unclear.