Merck's ($MRK@US) first-quarter revenue dropped by 9 percent from the same period last year due to an 88 percent drop in sales of its Covid-19 antiviral treatment, Molnupiravir. Adjust earnings per share were $1.40 versus the $1.32 expected, and revenue was $14.49 billion versus the $13.78 billion expected. Lower sales of diabetes treatments sitagliptin and a similar diabetes treatment also impacted the pharmaceutical company's results. Sales of Keytruda, Merck's blockbuster antibody treatment, increased 20 percent, and Gardasil, Merck's HPV vaccine, grew 35 percent. Merck raised its full-year adjusted earnings outlook and increased its 2023 sales forecast.