[Slow-release morphine liquid suspension for the therapy of cancer pain and non-cancer pain-A pilot study.].

INTRODUCTION: For pain therapy different methods of application are essential, because side effects or swallowing difficulties may prevent the natural oral application of analgesics. Up to now only tablets have been available for sustained-release morphine. We investigated a suspension of this drug in different pain states.
METHOD: Slow-release morphine liquid suspension was administered for 3 weeks in two different groups of patients. Group I included patients previously on a combination of non-opioid analgesics and weak opioids with unsatisfactory pain relief (pain scores > 5 of VAS 0-10). Group II were patients with well-controlled pain on strong-acting opioids. In these patients, the medication was changed to slow-release morphine liquid suspension. Intensity of pain, capacity, subjective feelings and side effects were recorded throughout the investigation period.
RESULTS: A total of 18 patients were included in the study, 8 in group I, 10 in group II. Twelve patients suffered from cancer pain. A pain reduction of at least 50% was achieved in 6 of 8 patients in group I. In 4 of 10 patients in group II the pain relief already obtained was improved further. In 8 of 18 patients the study had to be terminated. The reasons for this were unsatisfactory pain relief, increasing side effects distaste on intake. The average daily dose of morphine in group I was 132.5 mg, 151 mg in group II. Capacity did not change under slow-release morphine suspension. Constipation was the most, frequent side effect (67%). Ninety-three percent of all patients described the sweetish taste of the liquid preparation as unpalatable. DISCUSSION: These first results show that liquid slow-release morphine suspension can provide pain relief similar to slow-release morphine tablets. Consequently, slow-release liquid morphine suspension provides a suitable alternative, especially in patients with swallowing disorders.