The present invention relates to a medicine for the treatment of diseases in which Nav1.7 participates, specifically, diseases such as neuropathic pain, nociceptive pain, inflammatory pain, small fiber neuropathy, erythromelalgia, paroxysmal extreme pain, urination disorder, and multiple sclerosis. The medicine contains a compound represented by formula (I) or a pharmacologically acceptable salt thereof. [In formula (I), R1a, R1b, R1c, and R1d each represent a hydrogen atom, a halogeno, cyano, a C1-4 alkyl, a C1-4 alkoxy, etc., provided that at least one of R1a, R1b, R1c, and R1d represents a C6-10 aryl, a C6-10 aryloxy, etc.； R2 and R3 each represent a hydrogen atom, a C1-6 alkyl, a C3-10 cycloalkyl, etc.； R4 represents a hydrogen atom, a C1-6 alkyl, a C3-7 cycloalkyl, etc.； m indicates 0, 1, or 2； and L represents CR7R8 (where R7 and R8 each represent a hydrogen atom, a hydroxyl group, a C1-4 alkyl, a C1-4 alkoxy, etc.).]
