Hydromorphone Injector Pen for Rescue Dose Delivery

VIENNA, Austria—Even cancer patients whose pain is well controlled with regular daily opioids sometimes need rescue doses for breakthrough pain. For inpatients, this is often done with injected doses. Hakan Samuelsson, MD, has tested an injector pen that patients can use for self-administration of rescue doses. A pilot study suggests that this approach may be a useful option for most patients who need rescue opioid doses, he reported at the 9th World Congress on Pain.

The study included seven cancer pain patients who were on maintenance treatment with stable doses of either trans-dermal fentanyl (Duragesic) (4 patients) or slow-release morphine (3 patients). Cartridges of hydromorphone were prepared such that use in the injector pen provided a dose equivalent to one sixth of the patient’s daily opioid dose.

“Six patients felt safe with the injector pen and continued the trial for a mean of 81 days (range, 13 to 191 days),” Dr. Samuelsson reported. The treatment was stopped in one patient “for medicolegal reasons,” not further described.

The mean number of injections per day was 4.8 (range, 1 to 18). Injected doses ranged from 1 mg to 18 mg of hydromorphone.

“The users rated handling of the equipment as ‘easy’ in seven cases and ‘difficult’ in one case,” Dr. Samuelsson said. “Mechanical injector failure occurred on three occasions.”

The researchers concluded that self-administration of subcutaneous hydro-morphone by an injector pen “can offer fast and reliable relief of breakthrough pain during opioid medication for advanced cancer pain.”