Had week of amoxicillin before my root canal on infected abscess tooth. post root canal, clindamycin causing bad side effect gerd/ sob. any equivalen?

Amoxicillin: A penicillin like Amoxicillin or Augmentin (amoxicillin and clavulanate) should work too but check with your dentist. In sure if you tell them you are reacting to the clindamicin they will give you an appropriate alternative.

Yes: Without knowing you complete medical history, and the specific dental situation that we are dealing with, it would not be prudent to suggest alternative medications or how best to treat you. The dentist who is actually treating you would be the best one to make these decisions. There are antibiotic alternatives for you and ways to deal with this issue.

There is: Normally clyndamycine is the drug of choice in this case where anaerobic bacteria is the cause of the abscess , but there are alternatives in broad spectrum antibiotics, your dentist would be able to prescribe one for you. Make sure you eat before taking your meds. As that might help with digestive problems.

Yes: Yes, several. But it should be the dentist who actually treated you and who is most knowledgeable about your medical and dental history to make that decision.

No need: Latest research demonstrated that antibiotics are of no benefit in treating symptoms after root canal treatment. Take NSAIDs OTC or Tylenol (acetaminophen) for swelling and pain control.