The present invention provides a method of orally treating opiate dependency in a patient in need thereof. The method includes: orally administering an aqueous composition including: tetrahydrocannabinol (THC); one or more aprotic solvents, for example, dimethyl sulfoxide; one or more protic solvents, for example ethanol; and water. Methods of orally reducing or preventing opiate withdrawal, orally reducing or preventing opiate withdrawal symptoms, orally treating post-surgical and chronic pain in a patient are also provided.