Hello there. i have gone through your query and understand your concern Macrobid contains nitrofurantoin which is commonly advised and effective for bladder infections or cystitis.macrobid has near zero incidence of sore throat as side effect. Your symptoms sore throat ,bad breath and gum swelling are associated in my opinion. it is possible that wisdom tooth eruption might have caused inflammation of gum flaps making it difficult to come out and also caused inflammation in and around gums of adjacent teeth which can be called gingivitis and pericoronitis. Chances are there could be food particles lodged into gum pockets causing infection and leading to your sore throat. i would recommend you to visit a dentist to evaluate the dental hygiene,regarding wisom tooth and possible gum infection. In the mean while,please maintain strict dental hygiene by brushing twice daily,using a mouthwash twice daily and then using saline gargle twice or thrice daily which would help the gingivitis and sore throat also. take ibuprofen if needed for pain relief and restrict to max two tablets daily and i would recommend you to start antibiotics preferably amoxicillin plus clavulanic acid twice daily for 5 days. i hope this measures could help you out and probably save you from a dentist visit.hope this clears your concerns. take care and good day hope it helps and followup if needed