In the absence of specific authorization to refill, when the refilling of a prescription calling for a controlled substance or dangerous drug needed for the continuation of a treatment of a chronic or continuing illness is considered necessary and the pharmacist is unable to communicate with the prescribing practitioner, the pharmacist may, if in his or her professional judgment the pharmacist feels that the controlled substance or dangerous drug should be provided for the patient, furnish a sufficient supply of the medication to provide for the continuation of treatment until such time as he or she can communicate with the prescribing practitioner personally.
NRS 639.2394