Ritalin & Alcohol causing blackouts? | ADHD Information

Hi there, this is my first post, and I am hoping someone can help me. This is a problem that has occurred quite a few times.
My 22 yr old son has ADHD and takes Ritalin.  He likes to go nightclubbing a couple of nights a week, and has quite a few drinks.  He is into drinks like  bourbon and coke, absinthe, sambucca etc. 
He has had a couple of experiences where he has blacked out and not remembered anything that he has done.
Last week for instance, he had 2 drinks, went to the toilet, came back drank his 3rd drink and that's the last he can remember. 
He apparently left after only the 2nd set of music, and was also accused of trying to kiss his best mate's girlfriend, (he doesn't even like her). He was meant to go from the nightclub to his fathers and ended up back at my place with no memory of it at all!  He lost his keys, wallet, jacket, mobile phone.  He thinks his drink was spiked.  But now his friends are saying like "oh yeah, right your drinks are ALWAYS spiked!" 
Is it possible that the ritalin and the alcohol could be causing these blackouts?  Anyone else had any similar experiences, or is he just unlucky and has been having his drinks spiked? 
I really want to help him with this, cos now his best friend won't have anything to do with him, and obviously I am worried about what could happen to him during these blackouts.

He likes to go nightclubbing a couple of nights a week, and has quite a few drinks.  He is into drinks like  bourbon and coke, absinthe, sambucca etc.

These are some heavy duty kinds of drinks here. If he's drinking to blackout he has a problem. Please get him some help, on or off Ritalin I'd be concerned.

Thank you for replying to my post, I appreciate your comments and have taken them on board.
But the thing is, he is not drinking to black out, he only had 3 bourbon and coke drinks in a period of 2 hours !!! 
So the concern is, is someone spiking his drinks, or is it the ritalin in his system??? 
I personally think  his drink was spiked when he left it on the table and left the room.... but........   I am really worried bout this! 
He said he didn't have any ritalin that day, cos he was going out.  He doesn't take ritalin when he goes clubbing, but it could still be in his system from the day before couldn't it????  
Anyone else out there experience problems with alcohol and ritalin???

Hi there.

In my opinion NOBODY goes to blackoutīs or looses everything etc because of dringin to little of alcohol.

Despite the Ritalin I think the problem here is the alcohol.

Hi,

  Ritalin does not interact with alcohol.  If he is having blackouts, it is definately the alcohol. Three Bourbon and cokes within 2 hours is above the legal limit for driving. [was it on a full stomach or empty stomach?]

If he is having blackouts, he is either consuming more than he says or he has a problem with an inability to tolerate alcohol or had alcohol poisoning.

As it turns out his drink was spiked!!!!! 
He was not the only person that this happened to last week!
He went back to the night club on Saturday night, and sat down and had a talk to his best mate and a few other friends, and this is what happened....

He tucked his 3rd drink away while he went to the toilet.  While he was gone a substance called "G" was put into his drink.  It is a green liquid, and the equivalent of 1 shot of whisky is enough to make you lose your memory of everything that you do, and also over stimulates your sexual hormones (you get really horny, randy etc). 
It is apparently a relatively new thing that has arrived in Australia.
So now he and his mates are going to be on the watch out for these people doing this, try and catch them out, and then get the police involved.

He and his friends have been going to the same nightclub for approx 4 yrs and are on good terms with the management and the bouncers etc.

He does not drive, and no he does not get that drunk, as before I was put on medication that makes me sleepy of an evening, I used to go and pick him and his friends (boys and girls) up and take them all home, and none of them drink heavily or have been over the top drunk. 
Now they share taxis home.
He is very lucky as his best mate is 27 (and a non drinker) always looks out for him, and makes sure that he doesn't drink too much.  Also he can't afford the money to buy too much alcohol as he only gets casual work at the moment, and he is saving to go overseas to attend his brothers wedding.
The only time that he has drunk to excess and got smashed was the night of his 21st, and I drove them all home that night too.
He also does not take Ritalin when he goes out nightclubbing.
So please you guys out there, do not put your drinks down anywhere, even hiding them away is not safe.
These people who spike drinks particularly look out for drinks that have been tucked away!!!!
Only put your glass down when it is empty!!!! 
I am so relieved that he was able to make it home safely that night. Because on the Saturday morning he was walking around our house in a total daze and totally disorientated.  I have never seen him like that before, and it was scary to see.
The problem has been solved.! 
Thanks to everyone for replying to my post and for your help. I really appreciate it.