BACKGROUND Slamming has been increasing internationally for ten years, mostly among men who have sex with men. Slamming consists of injecting psychostimulants (including new psychoactive substances-NPS) intravenously to increase sexual performance. OBJECTIVE The objective of our work was to analyse drug-drug interactions related to slamming. METHODS Drawing upon a reported case of a slam session describing hour by hour the intake of substances, we performed a drug-interaction analysis using international references and a comprehensive literature review. High doses of sildenafil, GBL and 3-MMC were reported during the 40-hour session described. The specific drug-interaction research was performed using 9 references and 65 of the 209 records identified in the literature review. RESULTS Pharmacological data regarding nonmedicated substances were scarce. Regarding pharmacodynamics, the risk was high at the cardiovascular level and was related to the vasodilatation effect of sildenafil and the adrenergic and serotoninergic properties of stimulants; this risk may increase with usual treatment (involving other vasodilators or central depressants). Regarding pharmacokinetics, the major interactions concerned metabolism by CYP3A4 and CYP2C9, leading to interactions, particularly with HIV medication. CONCLUSIONS This innovative work provides pharmacological information on drugs that are commonly used in slamming, allowing the development of effective medical-management protocols and the provision of risk-reduction counselling.