Problem: The results of her pap test come back and she has bacterial vaginosis. Her primary care provider starts her on oral metronidazole to treat this infection. You educate Lisa on metronidazole's common adverse effects and caution her to avoid alcohol while taking it. Why do you caution her to avoid alcohol while on metronidazole? Need Assignment Help? Alcohol will decrease metronidazole's effectiveness. Alcohol will result in decreased renal function. Alcohol will cause intense vomiting and flushing. Alcohol will increase metronidazole concentrations.