How Long Meftal P Can Be Given To Child Without Side Effects?

My son who is 8 yrs old has tonsilitis with high fever.Doc advise me to give him 7ml of meftal p(every 8 hrs if fever persist).I want to know how safe meftal p is and for how long can you give this medicine without any side effects? He is on meftal p since Saturday night(5 doese uptill now).Also want to know when(at what temp) should a switch be made from crocin to MeftalP