California Business And Professions Code Section 2241

(a) A physician and surgeon may prescribe, dispense, or administer prescription drugs, including prescription controlled substances, to an addict under his or her treatment for a purpose other than maintenance on, or detoxification from, prescription drugs or controlled substances. (b) A physician and surgeon may prescribe, dispense, or administer prescription drugs or prescription controlled substances to an addict for purposes of maintenance on, or detoxification from, prescription drugs or controlled substances only as set forth in subdivision (c) or in Sections 11215, 11217, 11217.5, 11218, 11219, and 11220 of the Health and Safety Code. Nothing in this subdivision shall authorize a physician and surgeon to prescribe, dispense, or administer dangerous drugs or controlled substances to a person he or she knows or reasonably believes is using or will use the drugs or substances for a nonmedical purpose. (c) Notwithstanding subdivision (a), prescription drugs or controlled substances may also be administered or applied by a physician and surgeon, or by a registered nurse acting under his or her instruction and supervision, under the following circumstances: (1) Emergency treatment of a patient whose addiction is complicated by the presence of incurable disease, acute accident, illness, or injury, or the infirmities attendant upon age. (2) Treatment of addicts in state-licensed institutions where the patient is kept under restraint and control, or in city or county jails or state prisons. (3) Treatment of addicts as provided for by Section 11217.5 of the Health and Safety Code. (d) (1) For purposes of this section and Section 2241.5, addict means a person whose actions are characterized by craving in combination with one or more of the following: (A) Impaired control over drug use. (B) Compulsive use. (C) Continued use despite harm. (2) Notwithstanding paragraph (1), a person whose drug-seeking behavior is primarily due to the inadequate control of pain is not an addict within the meaning of this section or Section 2241.5.