A randomized phase 3b 4 study to evaluate concomitant use of topical ivermectin 1 cream and doxycycline 40- mg modified- release capsules, versus topical ivermectin 1 cream and placebo in the treatment of severe rosacea. doxycycline alternatives Chehab MA, Thakor AS, Tulin- Silver S, Connolly BL, Cahill AM, Ward TJ, et al.