Final answer:
Metronidazole (Flagyl) is related to several oral side effects, but not xerostomia.
Step-by-step explanation:
The correct answer is D. Xerostomia. Xerostomia refers to dry mouth, which is not a known side effect of Metronidazole (Flagyl). The other options, A. Black hairy tongue, B. Metallic taste, and C. Gingival hyperplasia, are all documented side effects of Metronidazole.
The oral side effects commonly related to metronidazole include A. Black hairy tongue, B. Metallic taste, and D. Xerostomia (dry mouth). These symptoms can occur because metronidazole can affect the normal microbiota of the mouth. It's also used to treat infections such as trichomoniasis, which may present with urinary discomfort and discharge. When antibiotics like metronidazole are taken, they can disrupt the balance of microorganisms in the body, sometimes leading to unpleasant side effects or secondary infections as beneficial bacteria are diminished.