Is It Safe To Give Only Breast Feed,ORS And Medication For Vomiting?

Hi Doctor, My baby of 1 yr old started vomiting after we traveled in a train for almost 24 hrs to a remote place. On consulting a Pediatrician in the nearest town, he told the baby is suffering from slight infection and given Emeset Syrup to stop the vomiting. The baby was fine for two days without vomiting but loss of appetite. After returning back again on train we consulted a Pediatrician who examined the baby and said there was no infection but prescribed Nutralin B syrup and Hysin Syrup to increase the Appetite. After using the medicines once in the morning the baby again stared vomiting in the evening twice? We see the symptoms of dehydration and weakness in the baby. Is it safe to continue the Nutralin and Hycin Syrups? Please help suggest any precautions to be taken. It is ok to continue with ORS solution, coconut water and breast feed even if the baby does not take any solid food? Medicines Used/Using: 1. Emeset (Ondansetron) - 2.5 ml - 3 times a day - 3 days 2. Nutralin B Syrup - 5 ml - 2 times a day - 5 days 3. Hysin Syrup (cyproheptadine) - 2.5 ml - 2 times a day - 5 days