This medication patch may be harmful if chewed or swallowed. If someone has overdosed, remove the patch if possible. For serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: nausea/vomiting that is severe or doesn't stop, excessive sweating, very slow heartbeat, slow or shallow breathing, seizure.