My Son Is 1 Year And 7 Months Old. His

My son is 1 year and 7 months old. His weight is 10.40 kg. Doctor said that his weight is low compared to normal value and advised to give zincovit syrup for weight gain. Also he advised to give worm eradication syrup (bendex suspension) 5 ml at night. Iam not clear that those suspension are advised only for 2 years and above. Should I give those medicines to my son.? Please help.