Kashayams are the liquid dosage forms. They are prepared by adding dry herb powders to water, boiled, filtered and used when still lukewarm. They are called decoction, herbal teas etc. Kashayam is one of the primary dosage forms of Ayurveda and widely used in an array of diseases.
Read related: Kashayam (Kwath) – Herbal Teas Preparation, Benefits, Usage
As a general rule, Kashayas are administered 15-30 minutes before food.
In Kerala they are given on empty stomach 6 am and 6 pm. It makes sense in ama or ajeerna (indigestion) conditions. Kashayas contain water soluble active principles of herbs. So, the herb active principles are dissolved in water medium. This makes the digestion and absorption of Kashaya very easy.
If they are given before food, their absorption happens in the quickest possible time and the patient’s body gets immensely benefited due to this.
Read related: Kashayam preparation – Easy Rules To Follow
This does not mean that all kashayas should only be given before food.
For example, going by the bheshaja sevana Kala rules (primary rules for time of medicine adminstration) kashaya can be given after food in case of Udana Vata.
Read related: How Time Of Medicine Administration Is Decided In Ayurveda?
So, based on the Dosha, disease condition, tissue involved etc factors, the timing of medicine administration can be altered.
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This rule also applies to Arishta and Asavas
Arishta and Asavas are- fermented liquid Ayurvedic medicines are usually administered after food.
By default arishta s are given after food, thinking fermented liquids before food can cause stomach irritation.
This rule again can be overruled with bheshaja sevana Kala rule.
For example, in Apana Vata vikruti, arishta asava can be given before food.
Or as in case of repeated urge disorders such as hiccups (hikka), cough, vomiting etc, either kashaya or arishta can be administered repeatedly, many a times a day.
Finally, the time of medicine administration depends largely on the wisdom of the doctor.