Final answer:
Metronidazole is not available as a tincture; it is available in forms such as tablets, gel, and cream.
Step-by-step explanation:
Metronidazole is not available as a tincture. It is available in various other dosage forms, including tablets for oral administration, gel, and cream for topical application. The route of administration for any medication is chosen based on the drug's properties and the intended use. Drugs like niclosamide, which are not absorbed easily from the gastrointestinal (GI) tract, are useful for treating diseases of the intestinal tract directly. Metronidazole is used to treat various infections, and its availability in different forms allows for flexibility in treatment depending on the condition being addressed.