Cal. PEN § 2653

(a) If a physician employed by the Department of Corrections or the Department of the Youth Authority certifies in writing that a particular medical treatment is required to prevent a violation of Section 147, 673, 2650, or 2652, or is required to prevent serious and imminent harm to the health of a prisoner, the order for that particular medical treatment may not be modified or canceled by any employee of the department without the approval of the chief medical officer of the institution or the physician in attendance unless an inmate or ward has a known history of violent or otherwise disruptive behavior that requires additional measures to protect the safety and security of the institution specified in writing by the warden or superintendent, or unless immediate security needs require alternate or modified procedures. Following any necessary modified or alternate security procedures, treatment of the inmate or ward shall be effected as expeditiously as possible.

Nothing in this section shall be construed to prevent a registered nurse from questioning, or seeking clarification of, an order from a physician that in the professional judgment of that nurse endangers patient health or safety, or otherwise is contrary to the professional ethics of the registered nurse.

(b) Any person who violates this section shall be subject to appropriate disciplinary action by the department.