hi, thank you for your query Bactrim is a combination of two antibiotics, sulfamethoxazole and trimethoprim. the common side effects include- cough, feeling short of breath; diarrhea that is watery or bloody; feeling restless or irritable, confusion, hallucinations, seizure; slow heart rate, weak pulse, severe tingling, numbness, muscle pain or weakness; nausea, stomach pain, loss of appetite, itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes); fever, chills, body aches, flu symptoms; or urinating less than usual or not at all. apart from these weakness can also be seen as dizziness, spinning sensation;ringing in your ears; all of these symptoms though not rare should be taken note of. kindly consult your GP so as to get a throrough general examination. thanking you, wishing you good health