Hydroxyurea capsules usp are an antineoplastic agent .significant tumor response to hydroxyurea capsules usp has been demonstrated in melanoma, resistant chronic myelocytic leukemia, and recurrent, metastatic, or inoperable carcinoma of the ovary.hydroxyurea, usp used concomitantly with irradiation therapy is intended for use in the local control of primary squamous cell (epidermoid) carcinomas of the head and neck, excluding the lip.