Smith's death was ultimately ruled an accidental drug overdose of the sedative chloral hydrate that became increasingly toxic when combined with other prescription drugs in her system, specifically four benzodiazepines: Klonopin (clonazepam), Ativan (lorazepam), Serax (oxazepam) and Valium (diazepam). Furthermore, she had taken Benadryl (diphenhydramine) and Topamax (topiramate), both of which block sodium channels, likely intensifying the sedative effects of the chloral hydrate and benzodiazepines. Despite rumors of methadone use due to its involvement in the death of Smith's son, Perper only found methadone in her bile, indicating it was probably ingested 2–3 days prior to her death, and therefore was not a contributing factor. The autopsy report indicates that abscesses on her buttocks, presumably from prior injections of vitamin B12 in the form of cyanocobalamin, as well as human growth hormone, and viral enteritis were contributory causes of death. Tests for influenza A and B were negative.