The Great Martyr Panteleimon (martyred c. AD 305) is one of the great Unmercenary Physicians of the Orthodox Church. Listen to an account of the life of St. Panteleimon on Ancient Faith Radio or read an account of his life on the Greek Orthodox Archdiocese website.
An Akathist to Great Martyr-Healer Panteleimon, a service through which we ask for the intercessions of St. Panteleimon on behalf of the sick for the healing of their souls and bodies, is available online. The text has been made available as a PDF file by St. Barbara Antiochian Orthodox Church in Costa Mesa, CA.
Here is a selection from the Akathist:
Possessed by a storm of polytheistic thoughts, the impious Emperor was confused on learning from the doctors who
were jealous of thee that thou healest all kinds of incurable illnesses by the name of Christ. And we, glorifying with gladness our wonderful God in thee, cry to Him: Alleluia! (Kontakion 4)
Most Holy Saint and Martyr Panteleimon-the-Healer, intercede to the Most Merciful God for [Name(s)] for the healing of his (or her, their) soul(s) and body (bodies).
When the people of Nicomedia heard of thy great compassion for the suffering and of thy free healing of all illnesses, all rushed to thee with faith in the healing Grace in thee, and receiving swift healing of all their diseases they glorified God and magnified thee, their most gracious healer, crying to thee:
Rejoice, thou who art anointed with the myrrh of Grace!
Rejoice, sanctified temple of God!
Rejoice, great glory of the pious!
Rejoice, firm wall of the oppressed!
Rejoice, thou who surpassest the wise in knowledge!
Rejoice, thou who enlightenest the thoughts of the faithful!
Rejoice, recipient of divine gifts
and source of many of the Lord’s mercies to us!
Rejoice, speedy helper of the suffering!
Rejoice, harbor of the storm-tossed!
Rejoice, instructor for those astray!
Rejoice, thou who dost heal the sick freely!
Rejoice, thou who dost impart healing abundantly!
Rejoice, Great Martyr and Healer Panteleimon! (Ekos 4)