Marijuana and tobacco co-administration in blunts, spliffs, and mulled cigarettes: A systematic literature review

Blunts and spliffs/mulled cigarettes combine marijuana and tobacco for co-administration (use at the same time, in the same product). Co-administration of marijuana and tobacco presents significant potential for nicotine exposure, and may lead to exclusive tobacco use patterns, nicotine addiction, and compounded health effects. No review articles have summarized the number and nature of studies published on these co-administered products.

Keywords "(blunt* OR spliff OR mull* OR joint) AND (tobacco OR smok* OR cigarette) AND (cannabis OR marijuana OR hashish)" were searched in the published literature. A total of 220 articles were considered for inclusion, 49 were reviewed by two independent qualitative coders, and 45 were included in this review.

Of the 45 articles, most (n=27) of studies were observational or descriptive; ten were qualitative, five employed causal designs, and three were mixed methods. A majority of the studies assessed blunts; only 11 studies assessed spliffs/mulled cigarettes. Many studies focused on sub-populations of youth, males, and African Americans. Use of co-administered marijuana and tobacco products was associated with several indicators of problematic use patterns, including perceptions of less risk, dependence on nicotine and marijuana, and greater subjective effects related to marijuana.

Literature on marijuana and tobacco co-administration comes largely from qualitative and observational/descriptive studies. In addition to continued surveillance, experimental research that directly assesses the smoking patterns of co-administered marijuana and tobacco products as compared with to those of marijuana and tobacco only products is needed to determine the potential long-term health consequences of using blunts, spliffs, or other co-administered products.