Butabarbital, calcium/magnesium/potassium/sodium oxybates. Both will increase consequences of one other by pharmacodynamic synergism. Contraindicated. Coadministration with alcohol or sedative hypnotics are contraindicated as a consequence of additive CNS depression. butabarbital will minimize the extent or result of vardenafil by influencing hepatic/intestinal enzyme CYP3A4 metabolis... https://davyu998eow8.westexwiki.com/user