While it may be a while before we learn the exact cause of Whitney Houston's death, the leading theory is that she fell asleep in the bathtub after taking Xanax (possibly in conjunction with alcohol).

These celebrities all died within the last five years as a result of prescription drugs.

Heath Ledger, actor (28). Combination of oxycodone, hydrocodone, diazepam, temazepam, alprazolam and doxylamine.
Greg Giraldo, comedian (44). Overdose on unspecified prescription medication.
Umaga, wrestler (36). Combination of hydrocodone, carisoprodol, and diazepam.
Eyedea, rapper (28). Overdose on unspecified opiates.
Jay Bennett, musician (45). Overdose on fentanyl via Duragesic patch.
Chase Tatum, wrestler (34). Overdose on prescription painkillers.
Anna Nicole Smith, model/reality star (39). Overdose on chloral hydrate.
Andrew Martin, wrestler (33). Overdose on oxycodone.
Danny Gans, comedian (52). Combination of hydromorphone (Dilaudid) and pre-existing heart condition. (Not actually an overdose.)
Sherri Martel, wrestler (49). Overdose on multiple drugs, including high amounts of oxycodone.
The Rev, musician (28). Combination of oxycodone (Percocet), oxymorphone, diazepam (Valium), nordiazepam, and alcohol.
Luna Vachon, wrestler (48). Overdose on oxycodone and benzodiazepine.
Missy, porn star (40). Overdose on unspecified prescription drugs.
Michael Jackson, musician (50). Death was ruled a homicide. Overdose of propofol and benzodiazepines.

[Image via SPLASHNEWS]