Injury on rightupper quadrant of abdomen

My was friend riding a bike yesterday around 12 am and met with an accident. An auto hit the bike and my friends bike's handle hit his  right upper side of abdomen and he fell on the road. There were red bruises on his arms and right abdomen. There is no pain or swelling on that part , but he was  unable to sit straight or he said it pained when he breathed heavily. So  we rushed to near by hospital immediately . The Doctor said, there are no cracks or fracture in diaphragm.he said there seems to be a muscular pain which isn't much to worry about . He prescribed us these medicines Pan 40 Enzoflam- 1 morning and 1 evening Clavam 625. After taking this tablet yesterday night, today morning ,my friend felt dizzy and nauseated. He said he felt like his head is spinning and could not look up properly. He vomited the breakfast twice. Are these symptoms because of these tablets or does it have to do anything with  the injury?Please help us by saying what should we do?