May be present in a syrup containing metronidazole ethanol?

Congratulations, you are right: Metronidazole exhibits a disulfiram effect but to a lighter extent. In addition, the amount of ethanol per intake will also be minimal. Maybe it can be gerisked anyway. Possibly consult the prescribing physician, who may have experience with this regulation? In the other case, you can use something else as a taste corrigens. See the question about a mouthwash with metronidazole and these about a solution with Gentamycin and metronidazole.