symptoms
of a very slow heartbeat (e.g., persistent dizziness, fainting, unusual fatigue), bluish discoloration of the fingers and toes, numbness/tingling/swelling of the hands or feet, decreased sexual ability, reversible hair loss, mental or mood changes, trouble breathing, cough, unexplained or sudden weight gain, increased thirst, increased urination.
Reference: Link: http://www.medicinenet.com/metoprolol/article.htm
Discuss these symptoms with your father's doctor.