Meridia and street drugs

I take Meridia once-a-day 15mg... I also took a half a pill of "E" or
ecstasy, on the weekend.

I heard that some of the combinations of these kinds of pills can be
dangerous. I know they can also be dangerous alone - but I'm a little
concerned that that one half-tablet of "E" could have now given me the heart
valve disease that fen/phen caused. Is it possible?

I also lost 7 lb dancing after that night... incidentally... maybe a good
combo, not a bad one? Joke.

Should I be worried about this one-time indulgence?

M./Toronto.