Melorazine

Melorazine is a sedative used by Starfleet medical personnel in the 24th century.

Dr. Elizabeth Lense prepared to distribute doses of concentrated melorazine to the crew of the USS da Vinci during the crisis at Galvan VI in 2376, to provide the option of a peaceful death prior to the anticipated violent destruction of the ship. (SCE eBook: Wildfire, Book Two)