Extended Release Stimulant Medication Misuse with Alcohol Co-administration

Dear Editor:

The co-administration of prescription stimulant medications with alcohol is an issue of growing concern. While the phenomenon of mixing alcohol and prescription stimulants is well documented (e.g. Barrett & Pihl, 2002; Darredeau et al., 2007) and linked with adverse outcomes (e.g. Markowitz et al., 1999), to date investigations have failed to differentiate between immediate release and extended release formulations of these medications. In this letter, we report on cases of intentional mixing of extended release prescription stimulants with alcohol to produce certain psychoactive effects.

As part of a larger study of non-prescribed stimulant medication use in Halifax, Nova Scotia, adult non-prescribed users of the extended release formulations Adderall XR (n=13), Ritalin SR (n=5), Concerta (n=4) and Biphentin (n=1) reported on their patterns of and motives for use during structured face-to-face interviews. Users of each of these medications reported having deliberately co-administered the drug with alcohol (Adderall XR 7/13; Ritalin SR 1/5; Concerta 1/4; Biphentin 1/1). Regardless of the specific medication used, the primary motivation for its co-administration with alcohol was to achieve desired psychoactive effects (e.g. to decrease or increase certain alcohol effects or to “get high”). Consistent with previous reports of stimulant-alcohol co-administration (e.g. Barrett et al., 2006), in most cases (80%) stimulant administration began after the onset of the drinking session. This is noteworthy given that the prior use of alcohol is known to have clinically significant interactions with a number of subsequently administered stimulant drugs, including methylphenidate (e.g. Perez-Reyes, 1994; Patrick et al., 2007). Thus, although extended release formulations may be unlikely to be inappropriately used when administered alone (e.g. Steinhoff, 2008), it is possible that the co-administration of alcohol may increase their abuse liability. This might occur through alcohol’s effects on the medications’ pharmacokinetic and/or pharmacodynamic properties (e.g. Patrick et al., 2007), via the production of new psychoactive metabolites such as ethylphenidate (e.g. Markowitz et al., 2000) or through another mechanism yet to be identified.

Findings suggest that various extended release formulations of prescription stimulants are liable to be misused when co-administered with alcohol. It is recommended that physicians explicitly consider potential interactions with alcohol and other commonly abused drugs when assessing the abuse potential of this class of medications. Non-stimulant alternatives should be considered for treating individuals at greatest risk for alcohol or medication misuse, such as those with a history of illicit substance use (Darredeau et al., 2007; Poulin, 2001).