Faruqi, S., Wright, C., Thompson, R., & Morice, A. H. (2014). A randomized placebo controlled trial to evaluate the effects of butamirate and dextromethorphan on capsaicin induced cough in healthy volunteers. British Journal of Clinical Pharmacology, 78(6), 1272-1280. https://doi.org/10.1111/bcp.12458