Cost Effectiveness of Naloxegol for Opioid-Induced Constipation in the UK.

BACKGROUND AND OBJECTIVES: Opioid-induced constipation (OIC) is the most common adverse effect reported in patients receiving opioids to manage pain. Initial treatment with laxatives provides inadequate response in some patients. Naloxegol is a peripherally acting µ-opioid receptor antagonist used to treat patients with inadequate response to laxative(s) (laxative inadequate responder [LIR]). A cost-effectiveness model was constructed from the UK payer perspective to compare oral naloxegol 25 mg with placebo in non-cancer LIR patients receiving opioids for chronic pain, and a scenario analysis of naloxegol 25 mg with rescue laxatives compared with placebo with rescue laxatives in the same patient population. METHODS: The model comprised a decision tree for the first 4 weeks of treatment, followed by a Markov model with a 4-week cycle length and the following states: 'OIC', 'non-OIC (on treatment)', 'non-OIC (untreated)' and 'death'. Two phase III trials with a follow-up period of 12 weeks provided data on treatment efficacy, transition probabilities, adverse event frequency and patient utility. Resource utilisation data were sourced from a UK-based burden of illness study and physician surveys. A UK National Health Service and Personal Social Service perspective was adopted; costs and health-related quality of life gains were discounted at a rate of 3.5 %. The model was run over a time horizon of 5 years, reflecting the average period of opioid use. RESULTS: Naloxegol has an incremental cost-effectiveness ratio of £10,849 per quality-adjusted life-year gained versus placebo, and £11,179 when rescue laxatives are made available in both arms (2014 values). Model outcomes were only sensitive to variations in utility inputs. However, the probabilistic sensitivity analyses indicate that naloxegol has a 91 % probability of being cost effective at a £20,000 threshold when compared with placebo. CONCLUSIONS: Naloxegol is likely a cost-effective treatment option for LIR patients with OIC. This assessment should be supported by further work on the utility of patients with OIC, including how utility varies with more granular measures of OIC.

Quantification of sinomenine in caulis sinomenii collected from different growing regions and wholesale herbal markets by a modified HPLC method.

Caulis Sinomenii is the dried plant stems of Sinomenium acutum and Sinomenium acutum var. cinereum and has been used in Chinese medicine for treating rheumatic diseases for over a thousand years. Previous studies have demonstrated that sinomenine is a major active constituent in both plants and can be utilized as an indicator of quality of the medicinal herb Caulis Sinomenii. Currently, S. acutum and S. acutum var. cinereum are growing over a wide geographical range in China, with equally wide variations in growing conditions. The objectives of this research were to determine whether there were difference between the species and varieties, and whether the different growing conditions could result in different quality by determining the content of sinomenine in different samples. A modified HPLC method using a diode array detector (DAD) has been developed for efficiently quantifying sinomenine in the plants. Using this method, fourteen samples of S. acutum var. cinereum and eleven samples of S. acutum from growing regions as well as eighteen herbal samples of Caulis Sinomenii from wholesale herbal markets were evaluated. The results showed that there was no marked difference in the content of sinomenine between the species and varieties collected from growing regions; however, a very large variation was found among the samples collected from different regions. Moreover, the content of sinomenine in the plants of large size (stem diameter>3 cm) was much higher than those of small size (stem diameter<1 cm). This implies that the growing region has greater impact on the quality of Caulis Sinomenii in terms of the content of sinomenine than the species and varieties. The results also showed that the content of sinomenine in commercial Caulis Sinomenii was markedly lower than that in the plants collected directly from growing regions. This suggests that to obtain the herb with higher content of sinomenine and thus ensure greater efficacy, both in clinical applications and in pharmacological investigations, the plant of Caulis Sinomenii with controlled stem size collected directly from growing regions is preferable.