Metronidazole is an antibiotic that is used to treat bacterial infections of the vagina, stomach, liver, skin, joints, brain and spinal cord, lungs, heart, or bloodstream. Metronidazole is also used to. Pill identifier results for pliva 333. Search by imprint, shape, color or drug name. White round pill with imprint pliva 333 tablet for treatment of with adverse reactions & drug interactions supplied by preferred pharmaceuticals, inc.