Muscle twitching/chest pains

Recently, I took some Annadin extra tablets for a sharp pain that occurred in my back, and I wondered whether the caffeine in that may be causing muscle twitching across my body right now.

I stopped taking them yesterday (Monday) and the twitches have not been as intense (have been using Deep Heat too) but I wondered whether, as I never have had caffeine drinks like Coke/Pepsi/Tea/Coffee before, whether the caffeine in the tablets could be causing the twitching, and whether, as I was taking about 6 tablets a day for a few days, my body hasn't reacted well to it?

I have also in the past 24 hours been having a sharp pain on my left side of my chest, and am not sure whether that could be possibly linked?

Also, what do you think I should do next? Thanks.

[Dr. Kokil Mathur]

Hi!
Whatever your age, sharp pains in left side of chest should be investigated for heart attacks immediately through 12 lead EKG. The pains can also be due to embolism in lung—again another emergency. Other possibilities are muscle pain, costochondritis, pinched spinal nerves.
Yes, caffeine overdose or its unaccustomed use can cause muscle twitches.
However, please consult a doctor and get this examined. Take care!