What Atropine Injection is used for. Atropine sulfate belongs to a group of medicines called antimuscarinic agents. Atropine Injection is given before anaesthesia to decrease mucus secretions, such as saliva. During anaesthesia and surgery, atropine is used to help keep the heart beat normal. Atropine sulfate is also used to block or reverse the adverse effects caused by some medicines and certain type of pesticides. Atropine Injection may be used for the management of other conditions that are not mentioned above.