A method of tolerance to narcotics in a patient in need thereof comprises administering a botulinum toxin to the patient. The botulinum toxin is selected from the group consisting of botulinum toxin type A, botulinum toxin type B, botulinum toxin type C, botulinum toxin type D, botulinum toxin type E, botulinum toxin type F and botulinum toxin type G, a fragment thereof, a hybrid thereof, a chimera thereof, and a combination thereof. The botulinum toxin may be administered by subcutaneous/intradermal injection. The subcutaneous/intradermal injection may be administered to and/or around the vicinity of a trigeminal nerve, a cervical nerve, a thoracic nerve, a lumbar nerve, and a sacral nerve of the patient. The therapeutically effective amount of the botulinum toxin administered is between about 1 unit and about 150 units.