My 4 Year Old Son Has A Double Ear Infection

My 4 year old son has a double ear infection with his left eardrum ruptured. How long will it continue to leak? He's been on Zithromax since Friday and we have an appointment with his ent on april 18 to discuss putting another set of tubes in his ears. He's also had his adenoids taken out over last summer. Isn't taking the adenoids out supposed to make it to where he doesn't get ear infections anymore?