Toxic, lethal drug:
• Chloral Hydrate
Therapeutic drugs:
• Diphenhydramine (Benadryl, an antihistamine)
• Clonazepam (Klonopin, anti-seizure drug, also used for panic attacks)
• Diazepam (Valium, used to treat anxiety)
• Nordiazepam (metabolite, produced in digestion of diazepam)
• Temazepam (metabolite, also produced during digestion of diazepam)
• Oxazepam (used to treat anxiety)
• Lorazepam (Ativan, used to treat anxiety)
Other drugs:
• Atropine (a drug used in resuscitation)
• Topiramate (Topomax, used to treat seizures, migraines, and sometimes
used as weight control drug)
• Ciprofloxacin (Cipro, an antibiotic)
• Acetaminophen (like Tylenol)
All of it was in Anna Nicole Smith at the time of her death, though there's no mention of being crushed by silicone...
http://www.cnn.com/2007/SHOWBIZ/TV/03/26/smith.autopsy/index.html