O Gunduz1, R D Topuz1, C H Karadag1, A Ulugol1. 1. Department of Medical Pharmacology, Faculty of Medicine, Trakya University, 22030-Edirne, Turkey.
Abstract
BACKGROUND: Combining drugs not only reduces specific adverse effects of each of the drug at a higher dose but also may lead to enhanced efficacy. Tapentadol is a recently discovered analgesic possessing μ-opioid receptor agonism and noradrenaline re-uptake inhibition in a single molecule. Taking into consideration, the pharmacological similarities between opioids and cannabinoids, we assumed that combination of cannabinoids with noradrenaline re-uptake inhibitors might also be effective. We therefore aimed to determine whether combining 1:1, 1:3 and 3:1 fixed ratios of the synthetic cannabinoid WIN 55,212-2 and the selective noradrenaline re-uptake inhibitor maprotiline exert anti-allodynic synergy on nerve-injured neuropathic mice. METHODS: Partial tight ligation of the sciatic nerve was made in mice; on pre-operative and post-operative 15 days basal mechanical allodynia, cold allodynia and motor function were assessed using von Frey filaments, hot/cold plate and rota rod apparatus. RESULTS: Mechanical and cold allodynia developed in all groups on post-operative 15 days. Development of cold allodynia was statistically significant in all groups (p < 0.05); therefore, cold allodynia was used in combination studies. As shown by isobolographic analysis, interactions of 1:1 and 3:1 ratios of WIN 55,212-2:maprotiline combinations were supra-additive, whereas 1:3 ratio was sub-additive. CONCLUSIONS: Overall, our data suggest that combination of a cannabinoid with a selective noradrenaline re-uptake inhibitor may offer a beneficial treatment option for neuropathic pain.
BACKGROUND: Combining drugs not only reduces specific adverse effects of each of the drug at a higher dose but also may lead to enhanced efficacy. Tapentadol is a recently discovered analgesic possessing μ-opioid receptor agonism and noradrenaline re-uptake inhibition in a single molecule. Taking into consideration, the pharmacological similarities between opioids and cannabinoids, we assumed that combination of cannabinoids with noradrenaline re-uptake inhibitors might also be effective. We therefore aimed to determine whether combining 1:1, 1:3 and 3:1 fixed ratios of the synthetic cannabinoid WIN 55,212-2 and the selective noradrenaline re-uptake inhibitor maprotiline exert anti-allodynic synergy on nerve-injured neuropathic mice. METHODS: Partial tight ligation of the sciatic nerve was made in mice; on pre-operative and post-operative 15 days basal mechanical allodynia, cold allodynia and motor function were assessed using von Frey filaments, hot/cold plate and rota rod apparatus. RESULTS: Mechanical and cold allodynia developed in all groups on post-operative 15 days. Development of cold allodynia was statistically significant in all groups (p < 0.05); therefore, cold allodynia was used in combination studies. As shown by isobolographic analysis, interactions of 1:1 and 3:1 ratios of WIN 55,212-2:maprotiline combinations were supra-additive, whereas 1:3 ratio was sub-additive. CONCLUSIONS: Overall, our data suggest that combination of a cannabinoid with a selective noradrenaline re-uptake inhibitor may offer a beneficial treatment option for neuropathic pain.
Authors: Cristina D Peterson; Kelley F Kitto; Eyup Akgün; Mary M Lunzer; Maureen S Riedl; Lucy Vulchanova; George L Wilcox; Philip S Portoghese; Carolyn A Fairbanks Journal: Pain Date: 2017-12 Impact factor: 7.926