The present invention relates to FLT3 receptor inhibitor for use in the treatment of neuropathic pain and chronic pain comprising a neuropathic component, wherein the daily dosage range per human adult per day of said FLT3 receptor inhibitor consists of a dosage range determined by a method comprising the steps of: (i) determining the minimal inhibiting dose of said FLT3 receptor inhibitor that induces the maximal inhibition of mechanical pain hypersensitivity, (ii) converting said dose to the Human Equivalent Dose (HED) by the allometric correction method, and (iii) establishing a daily dosage range per human adult per day wherein (iii-1) the lower limit of the said daily dosage range per human adult per day is the greater value between HED/20 determined via a rat model and 0.001 mg, and (iii-2) the upper limit of the said daily dosage range is the lower value between HED*20 determined via a rat model and 50 mg.