My friend and I snorted a 10 bag each of heroin. Our heads began to feel heavy after ten minutes. Soon we entered into a dream world in which we hallucinated heavily. We talked to people who did not exist and we were very confused. I could not remember anything about who I was. I only remember certain parts of the four-hour trip that followed but I felt like I was on mushrooms for about two days. We could not read for that amount of time (nothing was in focus). What do you think we took? PCP? Bad synthetic heroin?

My new job requires me to travel by airplane quite a bit. While flying, I sometimes have a cocktail or two, and most of the time, I am really loopy by the time we land. Some colleagues of mine have told me that one drink in the air is the equivalent of two drinks on the ground. How is this possible?

What is, overall, safer for your body: alcohol or marijuana?

My dad requires me to take weekly drug tests since he found out that I was smoking marijuana. My first test came back positive for marijuana and cocaine. I was not surprised about the marijuana because I had only been clean for five weeks, but I have never done cocaine. Is there anything that could have triggered a positive result? Could opium or mushrooms or any other drug possibly trigger this positive result?

1) I found a white powder in my friend's car and I think it might be cocaine. I'm not sure if it is or not. I don't know if I should confront him with it or what I should do. I don't want to see my friend get hurt, but if I'm wrong, I don't want to falsely accuse him of something like this. How should I go about handling the situation?

2) I am a first-year business student and have a little sister who is a junior. I think she is doing cocaine because I found some "paraphernalia" in her room last week. What can I do without damaging my relationship with her?

There seems to be no advice or information on the subject of alcohol poisoning that I can find on your web site. Recently I had a very bad experience that I think must have involved alcohol poisoning, and would like to have some information on the causes and signs of alcohol poisoning. Does beer before liquor have anything to do with it?

Do different kinds of alcohol (specifically liquor) actually make you different kinds of drunk? Or is it a cultural/psychological thing? I've noticed that I feel different when drinking wine vs. vodka vs. tequila, and I'm wondering if there's a physiological reason.

My 21st birthday is coming up. I've already had two sets of friends and my mom's boyfriend offer to take me to the bar for drinks. The problem is, I have never been drunk before, let alone consumed alcohol. I chose not to drink for a few different reasons and am not sure if I should change anything for my birthday. On the other hand, I feel that I am obliged to go out drinking on this "special occasion."