<s>[INST] Given an abstract text, please determine whether it contains any drug mentions. Provide a 'Yes' or 'No' answer based on the presence or absence of drugs. Abstract Text: Carvedilol Vs. Esophageal Variceal Band Ligation For Primary Prophylaxis Of Esophageal Variceal Hemorrhage:A Meta-Analysis And Systematic Review[/INST] Yes</s>