Chronic pain is the most common reason for the visits to the healthcare professionals. In chronic pain, the pain signals go on for weeks, months, or even years. This can be associated with injury, infection, headache, arthritis, low back strain, cancer etc. Various medications have been used to treat the same. The efficacy of once-daily extended-release (ER) hydrocodone, especially after previously taking morphine is well explained in this research study.

This post hoc analysis examined the effectiveness and safety of hydrocodone bitartrate (HYD) in patients with moderate-to-severe chronic pain who were previously taking extended-release morphine (morphine ER) for pain management. The primary analysis was an open-label, 12-month study. The study was conducted in 88 sites in the United States.

The study was approved by an institutional review board. Eligible patients were enrolled and titrated to a once-daily dose of HYD 20, 40, 60, 80, or 120 mg for a 45-day period. The subgroup of patients in this report was using morphine ER prior to study entry. After achieving a stable HYD daily dose, patients entered a 12-month maintenance period during which additional dose adjustment could be made and nonopioid or short-acting opioid medications could be received. Average pain over the last 24 hours was recorded daily (on a scale of 0 to 10) Patients completed the Brief Pain Inventory (BPI) short form, which assessed pain severity and the interference of pain in daily life, every 4 weeks during the maintenance period. Safety was assessed routinely.

Of the 26 patients who switched from morphine ER to HYD, 19 entered the maintenance period. At study entry, mean “average pain over the last 24 hours” was scored as 5.21. This was reduced to 3.90 by the time patients entered the maintenance phase; this level of pain control was maintained over the 12-month period, with 16 patients requiring no further HYD dose adjustment. BPI scores decreased for both pain severity and pain interference during the maintenance period. HYD was well tolerated.

The results of this subgroup analysis suggest that rotation from morphine ER to once-daily HYD in patients with moderate-to-severe chronic pain maintains or improves pain relief and does not increase safety concerns.