1. What should I do to fill a prescription at a participating pharmacy? Posted on September 11, 2017 at 12:41 pm.Written by advantage_admin You can fill out maintenance drug prescriptions at a preferred pharmacy, or you can request our mail-order pharmacy service. Maintenance drugs are identified as MO in the drug list, under the abbreviation descriptions and in the Requirements/Limits column. Post navigation 1. hat is the Teleconsejo hotline?2. What should I do if my prescription is not included in the Triple-S Advantage Drug List?