<s>[INST] severe pain a swollen jaw.  dentist did  a root canal and pain is gone and was given 500 mg amoxicillian 4 x a day. swelling is going down but tooth is still tender when biting down and  am experiencing extreme tiredness.  is this from the amoxicillian? [/INST] Hello dearThanks for your query at him Amoxycillin is an antibiotic it will decrease any infection that is present because of the root canal treatment . it will not decrease swelling not cause tiredness as the adverse effects.Regards </s>