No dribbling, but when i try to pee, it mostly just drips out. painful. i've been taking bactrim (sulfamethoxazole and trimethoprim) already for 48 hours. shouldn't it be working by now?

Urinary obstruction: I agree with Dr. Lin's answer - your symptoms suggest that you have an obstruction of outflow of urine, and that's not a problem that Bactrim (sulfamethoxazole and trimethoprim) will fix. An infection, if you have one, will not get better if an obstruction of outflow continues. You should see a doctor or go to ER to find out if you have an obstruction and to get treatment (a small catheter to drain and measure urine volume).