Drug and Alcohol Dependence 57 (1999) 23–28 Rapid cortical hemoglobin deoxygenation after heroin and methadone injection in humans: a preliminary report  Rudolf Stohler a, *, Kenneth M. Du ¨ rsteler b , Robert Sto ¨ rmer b , Erich Seifritz b , Irene Hug b , Jeanette Sattler-Mayr b , Franz Mu ¨ ller-Spahn b , Dieter Ladewig b , Christoph Hock b a Department of Psychiatry, Uniersity of Zu ¨rich, Milita ¨rstr. 8, Postfach 1930, CH-8021 Zu ¨rich, Switzerland b Department of Psychiatry, Uniersity of Basel, Wilhelm Klein -Str. 27, CH-4025 Basel, Switzerland Received 25 September 1998; accepted 13 April 1999 Abstract The short-term effects of intravenous opioids (heroin 20 – 300 mg, methadone 30 – 180 mg) on cortical hemoglobin oxygenation were examined by near infrared spectroscopy in ten opioid-dependent subjects and were compared with the effects of saline in ten age-matched normal controls. Heroin and methadone produced a rapid and dramatic decrease in cortical hemoglobin oxygena- tion. Saline had no effects. Opioid-induced acute deoxygenation of cortical hemoglobin is most likely associated with respiratory depression. Thorough medical monitoring is strongly recommended in intravenous opioid maintenance treatments. © 1999 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Heroin; Methadone; Cortical hemoglobin deoxygenation; Rush; Intravenous opioid treatment; Near infrared spectroscopy (NIRS); PROVE www.elsevier.com/locate/drugalcdep 1. Introduction The program for medical prescription of narcotics of the Swiss government (PROVE) is currently evaluating the treatment of heroin-dependent patients with in- jectable opioids (heroin, morphine, and methadone). One of the main reasons for this endeavor was that a considerable group of heroin dependents could not effectively be reached with methadone maintenance programs (Uchtenhagen et al., 1996) because of lacking rush sensations (Jaffe and Martin, 1993). Thus, the rush sensation appears to play a major role in reinforcement processes in opioid dependence. So far, the PROVE projects have generally been viewed to be successful in terms of retention in treat- ment, morbidity and mortality, legal behavior, and cost effectiveness (Uchtenhagen et al., 1997). However, con- sistent with the well established convulsant actions of morphine-like opioids (Reisine and Pasternak, 1996), epileptic seizures have been observed as a severe com- plication of heroin injections (Uchtenhagen, 1997). Throughout the observation period of 26 months, at least one epileptic seizure occurred in 10.75% (n =20), and two or more in 4.3% (n =8) of the 186 patients of the PROVE project located in Basel (Hug, 1997). It is supposed that there are even more cases since epileptic seizures are difficult to differentiate from other distur- bances of consciousness in these patients (Sagratella and Scotti de Carolis, 1993). In a prospective experiment the electroencephalo- graphic effects of intravenous heroin, methadone, and morphine in 19 patients have been examined (Stohler et al., 1996). Hyperexcitability was found in six heroin- and three morphine-treated patients, but this was not the case in methadone-treated patients. Additionally, pulsoxymetry during and after intravenous methadone (150 – 300 mg) in nine opioid dependent subjects yielded slight decreases in oxygen saturation (SaO 2 ) with the lowest values being 94% (unpublished data).  This study was conducted at the Department of Psychiatry, University of Basel * Corresponding author. Tel.: +41-1-291-1240; fax: +41-1-291- 1240. E-mail address: stohler@spd.unizh.ch (R. Stohler) 0376-8716/99/$ - see front matter © 1999 Elsevier Science Ireland Ltd. All rights reserved. PII:S0376-8716(99)00036-8