Tramadol 150mg tablets can use twice a day (morning and evening). It is specially made up into tablets that allow the body to absorb the Tramadol over a long period, so that dosing needs only to be twice a day. As all patients respond to treatment differently, your doctor may start you on a lower dose. Tramadol150 mg works by blocking pain signals from travelling along the nerves to the brain. The most common side effects of Tramadol 150mg are feeling sick and dizzy. Tramadol 150mg drops, injections and tablets are fast-acting. They start to work within 30 to 60 minutes. They’re used for pain that is expected to last for only a short time.