Charak Samhita
ज्वरे पेयाः कषायाश्च क्षीरं सर्पिर्विरेचनम् । षडहे षडहे देयं कालं वीक्ष्यामयस्य च ॥३०२॥
Peya , kashaya ( decoction), kshira (medicated milk), medicated ghee and purgation must be advocated every six days taking into consideration status of the diseases like Jvara.
english translation
jvare peyAH kaSAyAzca kSIraM sarpirvirecanam । SaDahe SaDahe deyaM kAlaM vIkSyAmayasya ca ॥302॥
hk transliteration by Sanscript