Ashtavargam Kashayam is herbal preparation in the form of tablet or in kashayam(liquid decoction) from.
Its usage:
In treating the vata disorders, like joint pain, bloating of abdomen.
Dosage:
12-24ml with equal quantity of hot water once on empty stomach or twice
1-2tab with warm water once or twice daily  or as directed by teh physician. 
Astavargam Kashayam Ingredients:
Bala – Sida rotusa / Sida cordifolia
Sahachara – Strobilanthes ciliatus
Eranda – Ricinus communis
Ginger
Rasna – Pluchea lanceolata
Devadaru – Cedrus deodara
Nirgundi  – Vitex negundo
Garlic
It is added with 8 parts of water, boiled and reduced to quarter part, filtered.
Reference: Sahasra Yoga.