Pharmacokinetics and pharmacodynamics of intranasal "snorted" heroin

The purity of illicit heroin in the United States has increased steadily over the last several years, while prices have fallen. Associated with this trend, there has been a recent shift among heroin addicts from intravenous injection to intranasal use ("snorting"). Because of the lack of information on this route of administration, we evaluated the pharmacokinetic and pharmacodynamic properties of intranasal heroin. Results were compared to the effects of heroin by the intramuscular route. Six healthy, male volunteers were administered single doses of intranasal heroin hydrochloride (6 and 12 mg), intramuscular heroin hydrochloride (6 mg), and placebo. Blood levels of heroin, 6-acetylmorphine, and morphine were measured by gas chromatography/mass spectrometry. Simultaneous physiological, behavioral, and performance measures were obtained. Peak blood levels of heroin were attained within 5 min of heroin administration by the intranasal route, similar to those observed for intramuscular administration. Generally, the pharmacokinetic profile of intranasal heroin was equivalent to that for the intramuscular route. Physiological, behavioral, and performance effects following intranasal administration were similar to the effects following intramuscular administration. The relative potency of intranasal heroin was estimated to be approximately one-half that of intramuscular administration. The efficacy of the intranasal route, combined with decreased heroin cost, reduced fear of infection, and the lack of requirements for additional drug paraphernalia, could make this an attractive route of drug administration to naive or infrequent drug users.