With yet another famous person dying from a toxic mix of prescription drugs & alcohol [or at least that is the current theory of what killed Whitney Houston], it got me wondering. Especially since she was apparently on Xanax and I also take xanax to sleep.

Is there a safe limit on scriipt drugs or a combo of them or is it different for each person? Should they all be considered 'deadly' and therefore, taken only when needed and only for a time? Or are we risking death with every pill?

All pills carry side effects, and some are more dangerous than others.  For example, Coumadin is much more dangerous than aspirin.  And when you start mixing drugs then the dangers increase significantly.  Drugs are tested for their effects with two drugs combined, not a whole compilation of drugs taken together.  Other factors include age.  The elderly are more prone to side effects that younger people.  This can be from dehydration, nutritional deficiencies, poor liver/kidney function, other drugs, etc.  So there are a number of factors that can affect how someone will react to drugs.

With Whitney Houston though they also mentioned that she was drinking.  Anti-anxiety drugs and alcohol are not a good mix.   I would not be surprised at all if her respiration shut down before she slipped under the water.

I have a friend whose husband is a total drug addict from taking about five or six heavy duty pain drugs, constantly, for many years now. I'm amazed he is still alive and he's only in his early 50s. He chokes on his food, he falls down a lot, he's barely functional but my friend just says he's in so much pain he can't NOT take these drugs.

But I digress.

He has several options such as addressing what is causing his pain in the first place.  If there are degenerative discs for example then he needs to strengthen the discs.  He can also use DL-phenylalanine to increase his dopamine levels so he can slowly wean off the pain meds.

Is the deadly dose or combo dose of scriipt drugs just basically a crap shoot?

Pretty much.  Again, all drugs have potential side effects but there is no way to know for sure what side effects will occur.  If someone takes Coumadin then we pretty much know that they are going to bruise like crazy and be at risk for hemorrhage if they injure themselves or they have an ulcer that starts bleeding.  But there is no way to know in what individuals the Coumadin will cause a stroke.

How does alcohol make it worse?

Depends on the drug.  Different medications can have different interactions with alcohol.  For example, the anti-anxiety drugs can interact with alcohol leading to respiratory suppression.  Taking alcohol with acetaminophen (Tylenol) can cause instant liver failure.