I have a patient on Sulfamethoxazole and Trimethoprim for systemic issues prior. we are a dental practice, she had extraction 2 days ago, did not give her the normal amoxicillin, would this have made a difference, patient return with pain in extracted site, an xray was taken, socket it clean, some swelling and tenderness around area. but we are wondering if there could be a cross reaction with giving her amoxicillin/clindamycin instead or together.