What Causes Vomiting After Taking Medication For Hematospermia?

Hi, I have a friend who has chronic prostatis and went to the doctor the other day..the urologist told him he had hematospermia...two days after being on an antibiotic, he has started vomitting..not able to go the bathroom...his vomit is black..I have tried everything to get him to go to the ER...concerned his throwing up blood ..he could have an obstruction...and now he has hiccups for 12 hrs...