MedPharm removes 'SDS Blocker' from inventory following HSI search WhatsApp. MedPharm issued a news release Thursday evening advising that they have removed a product called 'SDS Blocker' from their inventory following the execution of a warrant at their Guam office in Dededo on Tuesday. "The product was marketed and sold to MedPharm as an over-the-counter item by a local Guam distributor," states the ...