Tramadol and hyoscine N-butyl bromide combined in infusion solutions: compatibility and stability

More than two-thirds of patients with metastatic cancer experience pain. Tramadol is one of the most interesting and useful weak opioids used by palliative care units to treat moderate to moderately severe pain. Relief of distressful symptoms in terminally ill patients is of prime importance; a common practice is to administer opioid analgesics in conjunction with other drugs as hyoscine N-butyl bromide, which is very useful in reducing secretions in patients with inoperable malignant bowel obstruction. The pursuit for excellence in symptom control in patients unable to take oral medication has led to the administration of medications by other routes such as the subcutaneous route.

The purpose of this study was to fulfill the lack of information regarding the compatibility and physical stability of tramadol hydrochloride and hyoscine N-butyl bromide combined in infusion solutions.

The stability of nine admixtures (stored in polypropylene syringes) at 4 and 25 degrees C was assessed over a period of 15 days.

Nonstatistically significant losses of tramadol HCl and a maximum loss of 7% for hyoscine N-butyl bromide were obtained. Therefore, tramadol HCl (dose range, 100-400 mg/day) can be formulated together in saline with hyoscine N-butyl bromide (dose range 40-80 mg/day) for s.c. infusion using a 60-ml drug infuser for a duration of 7 days.