Hi El_Alexandar,
I'm sorry no one has responded to your question yet, i've been off line for a couple of weeks and i've only just had the opportunity to log on, it's summer over my side of the world (Australia)....
It's possible what you've experienced is actually to do with the muscle relaxer you were given, the most common side effects are tiredness, drowsiness, sedation effect, fatigue or weakness. If your still experiencing this please talk to your dr!
Hope that helps......JJ