Hydroxycarbamide causes inhibition of DNA synthesis during the S-phase of cell division by acting as a ribonucleotide reductase inhibitor resulting to cell death. It is S-phase specific.
Megaloblastic anemia, Decreased white blood cell count (neutrophils), Oligospermia (low sperm count), Azoospermia (absence of sperms)
Hydroxyurea is used in the treatment of sickle cell anemia.