Here are few prayers for Lord Dhanvantari who is an Avatara of Lord Vishnu.
śankham cakram jalaukam dadhad amṛta ghaṭam cāru dorbhis
chaturbhiḥ|sūkṣma svachhan hṛdayaṁśuka parivilasan maulim ambhoja
netram || kālam bhodojjvalāṅgam kaṭi taṭa vilasac cāru pitāmbarāḍyam |
vande dhanvantarim tam nikhila gada vana prauḍa dāvāgni nīlām ||
Salutations to Dhanvantari, who holds with his four arms - A conch (success), a wheel or disk of energy (freedom),a leech (purity) and a pot celestial ambrosia (happy, long and fulfilled life), in whose heart shines a very subtle, clear, gentle and pleasing blaze of light, this light also shines all around his head and lotus eyes, who by his mere play destroys all diseases like a mighty forest fire.
Om Namo Bhagavate Maha Sudharshana Vasudevaya Dhanvantaraye | Amrutha
Kalasa Hasthaaya Sarva Bhaya Vinasaya Sarva Roka Nivaranaya || Thri
Lokya Pathaye Thri Lokya Nithaye Sri Maha Vishnu Swarupa Sri
Dhanvantri Swarupa | Sri Sri Sri Aoushata Chakra Narayana Swaha ||
I bow down and pray to the Lord Dhanvantari who is the incarnation of Lord Vishnu and called as Sudarshana Vasudev Dhanvantari. You hold in your hands, the Kalasha filled with the nectar of immortality. Oh Lord, you can remove all fears and diseases. You protect all the three worlds and you are the well wisher of all created beings. You are the Lord of Ayurveda and the manifestation of Lord Vishnu. You are the ultimate healer of all the living beings. We worship you and pray you.
oṃ namo bhagavan vāsudeva dhanvantare | mahā-viṣṇu nārāyaṇa vaikuṇṭa |
ārogyaṃ dehi dehi | dirghāyuṣyaṃ dehi dehi | śrī mūrtaye namas-svāhā
Salutations to the Lord Dhanvantari, the all-pervading Principle of Health,The omnipresent one, the Ground of all Being, the un-impreded one. Grant me health. Grant me long-life. Salutations to the manifestation of auspiciousness, May my health and longevity be used for the welfare of all sentient beings.
Namani Dhanwanthary Aadi Devam | Surasura Vanditham Pada Padmam ||
Loke Jara Rugbhay Mrityu Nashakam | Datharam Eesham Vividhaushadhinam
I bow down in front of you Lord Dhanvantari. Your lotus feet is respectfully worshipped by the Dods and Demons. You have infinite powers to save the people from the miseries of diseases, ageing, fear of death and other sufferings. Oh Lord, please bless me with your grace and medicines so that I can also help the people with cures from their diseases.