Expert: Dr.Paul Skett - 8/11/2010

Question
Well long story short: I've been on a bunch of different medications for many different reasons. Pain, ADHD, sleep, muscular, and etc. All medications (or drugs such as alcohol) seem to go through my system pretty fast. They last around half, at best, of what they're supposed to. So 6 hours becomes more like 3. Or don't work at all.

For example: Adderall
10 mg: just ends my constipation and regular side effects.
20 mg: slightly more focused and a safer driver/calm.
30 mg: no difference.
40 mg: extremely more focused, really organized, extremely calm, and I can actually study so that my grades go to what they should be. Less distracted too.

I weigh 120 lbs, can eat more like I'm 180-220ish, can not drink for over a year then out drink someone twice my size and sober up long before they do.

So I'm curious if it could be that I have a natural tolerance to drugs? Maybe it's my metabolism? Or maybe it's not getting absorbed properly? Or possibly a combo? And are there any tests to find out?

It just sucks being on a high dose of pain meds and either it only lasts 3 hours (Lortab; or generic rather: hydrocodone/APAP 7.5-500) and after using it for 3 days it stops working altogether. Even took an extra one, did nothing. Ended up having to quit my job after that...

Answer
Hi, Russell,

Thanks for your question. Sounds like a combination of a number of factors here - whilst some people have a genetic tolerance to some drugs, this is unusual - most likely a combination of tolerance developing (develops very quickly to opioids)to the action of the drug(s), increases in metabolism caused by the drugs (some drugs can increase the metabolism of others including alcohol)and drug-drug interactions altering the effects of the drugs (also very common). Possibilities of some interactions at the level of drug uptake but this is less common.

Drugs (including alcohol) interact more than you might think at many levels. I spend most of my working life trying to work these out in legal cases!

Hope this helps.

Best wishes,

Paul