BACKGROUND
About 30—75% of patients experience severe pain after surgery, and less than 50% are satisfied with quality of pain relief. Therefore, research of efficacy and safety of the new analgesic — tyrosyl-D-arginyl-phenylalanyl-glycine amide acetate (Tafalgin) (selective agonist of μ1-opioid receptors) — in cancer patients after surgery is a pressing issue in modern anesthesiology.
OBJECTIVE
To analyze the efficacy and safety of postoperative therapy with Tafalgin in cancer patients.
MATERIAL AND METHODS
An open prospective cohort observational study included 101 cancer patients. In case of postoperative pain syndrome NRS score 3, Tafalgin 4 mg was administered subcutaneously. Nine (8.9%) patients received this drug alone, 92 (91.1%) patients — in combination with intravenous paracetamol 1 g four times a day. Pain syndrome was assessed after 15, 30, 45, 60 min, 2 and 4 hours. Satisfaction of doctors and patients with pain relief was assessed using a 5-point Likert scale. To assess significance of changes in pain intensity at rest and during movement over time, we used analysis of variance with repeated measures. For pairwise comparison of two time periods, we applied t-test for dependent samples. Differences were significant at p< 0.05.
RESULTS
Mean NRS score of pain before the first administration of Tafalgin at rest was 6.2±1.3 (moderate-to-severe pain). In 15 min after subcutaneous administration of opioid analgesic, pain significantly decreased to 4.9±1.5 points (p<0.001). One hour after administration of Tafalgin, pain intensity comprised 3.0±1.0 points (low-intensity pain). In most patients (73.3%), pain at rest did not exceed 3 points one hour after administration of Tafalgin. Pain following movement was similar to pain at rest. Before the first administration of Tafalgin, mean score of pain during movement was 7.0±3.5 points, after 1 hour — 4.5±2 points (p<0.001). There was high satisfaction of patients and physicians with analgesic therapy; 88% of physicians and 84% of patients rated the result of Tafalgin therapy as good or excellent. Physicians rated tolerability of therapy as excellent in 96 (95%) patients, good in 1 (1%) patient, and satisfactory in 4 (4%) patients. Side effects did not include severe and life-threatening adverse events (respiratory depression, oversedation). However, 6 (5%) patients complained of nausea that required traditional antiemetics.
CONCLUSION
Tafalgin significantly reduces postoperative pain syndrome after surgery for cancer. There was good tolerability in majority of cancer patients without dangerous adverse effects typical for traditional opioid analgesics. Research of selective μ1-opioid receptor agonist Tafalgin in routine clinical work is at the early stage and should be continued. Nevertheless, good prospects are visible for this drug to become a high-quality replacement for traditional opioids in postoperative period in cancer patients.
