What legal action's do I have if any and chances of recovery on the case listed below?

My 7 year old son who has been treated for Acute Lymphoblastic Luekemia has been mistakenly given the wrong dosage of his antibiotic, Septra for the past 2months or so. The script was written correctly, but the Pharmacist and tech's transcribed it wrong and therefore filled it incorrectly. This would be a case against the pharmacy, the pharmacists, and the tech's and store manager I would think. He was prescribed the the single dose of Septra of 80/400 BID, Saturday's and Sunday's every week as a profylatic, but was give the correct times/days/how often, but the wrong dosage of the double strength which is 800/160. Do I have a case? The only symptoms he has had is severe joint pain, diarahrea and nausea. Does he have a chance at pain and suffering as well? What dollar amount could he get? What attorney should I get for the Indianapolis area of Indiana? Any advice?