San Diego-based Advanced Medical Inc. said it will fire 225 employees, or 14% of its work force, and take an unspecified fourth-quarter charge related to its acquisition of Ivac Medical Systems Inc. The medical-products company discharged 125 of the workers and said it will fire an additional 100 during the next six months. The $400-million Ivac purchase created one of the largest makers of intravenous infusion pumps. The firings would reduce its work force to 1,375. In addition, Advanced Medical said it will consolidate its disposable-device factories in Tijuana in the second half of next year. Shares rose 37.5 cents to close at $3.75 on the New York Stock Exchange.