All of the following is true about hydroxyurea except:

Ans: B (Oral...) HYDROXYUREA# Hydroxyurea is an analog of urea whose mechanism of action involves the inhibition of DAM synthesis by inhibiting the enzyme ribonucleotide reductase, resulting in depletion of deoxynucleoside triphosphate pools. This agent exerts its effects in the 5 phase of the cell cycle.The drug is administered orally and has nearly 100% oral bioavailability.It is mainly used in chronic myelogenous leukemia, blast crisis of acute myeloid leukemia , psoriasis & sickle cell anaemiaHowever, it is also effective as an adjunct with radiation therapy(as radiosensitizer) for head and neck cancer and in treating essential thrombocytosis and polycythemia vera.Myelosuppression is the dose-limiting toxicity, but nausea and vomiting, mucositis and diarrhea, headache and increased lethargy, and a maculopapular skin rash with pruritus are also observed.