Do I need a prescription for metronidazole? Yes What preparations of metronidazole are available? Tablets: 250 and 500 mg. Tablets, extended release: 750 mg. Capsule: 375 mg. Cream: 0.75% and 1%. Lotion: 0.75%. Gel: 0.75% and 1%. Injection: 5 mg/ml How should I keep metronidazole ...