prazipro usage

[juuniz]

hi all.. i have a goldflake angel and flame and both were eating well for 3 days since bought (NLS pellets and mysis) until i dose prazipro..

now she seems to lost appetite and has a white poops.. just 2 days after dosing prazipro

Is it normal? or should i change water more often?

Thanks

water param as follow
amm nitrite 0
PH 8.0
temp 27-28 degree
salinity normal