Initial pharmacokinetic, safety and efficacy evaluation of nasal morphine gluconate for breakthrough pain in cancer patients.

Patients with controlled background pain associated with cancer frequently also experience episodes of moderate to severe intensity breakthrough pain. Opioid pharmacotherapy, particularly with oral morphine, remains the cornerstone for the management of cancer pain. Nasal administration of opioids provides a mechanism for more rapid drug absorption and more rapid onset of pain relief compared with oral dosing.