The Compendium of Kāśyapa 8.3.91

8.3.91

ūrdhvabhāge tvardhamātrā tathaiva ca virecane
vātapittakaphaghnānāṃ kaṣāye tu pradāpayet

For [drugs acting on] the upper tract, however, it is half the dose, and likewise in purgation. / But in a decoction that destroys vāta, pitta, and kapha, one should give