Labetalol is a medicine which works on your heart and blood vessels. It does this by blocking tiny areas (called receptors) where messages are received by your heart and blood vessels. As a result, the pressure of blood within your blood vessels is reduced, and your heart beats more slowly and with less force. When it is given by injection, it reduces blood pressure quickly, and for this reason it is used to keep blood pressure down during surgery, and in people who have had a heart attack.
This is a companion discussion topic for the original article at https://patient.info/medicine/labetalol-a-beta-blocker-trandate