hydroxyurea + tadalafil

Hydroxyurea + tadalafil is a combination of two small molecule drugs, hydroxyurea and tadalafil. Hydroxyurea is an antimetabolite that inhibits ribonucleotide reductase, leading to decreased DNA synthesis and cell proliferation. It is primarily used in the treatment of sickle cell anemia to reduce the frequency of painful crises and blood transfusions, as well as in certain cancers such as chronic myelogenous leukemia and head and neck cancers[3][4][6]. Tadalafil is a phosphodiesterase type 5 (PDE5) inhibitor that increases cyclic guanosine monophosphate (cGMP) levels, resulting in smooth muscle relaxation and vasodilation; it is commonly used for erectile dysfunction and pulmonary arterial hypertension. The combination has been studied for preventing recurrent ischemic priapism in men with sickle cell anemia, where both agents may act synergistically to reduce priapism episodes by improving vascular function[1]. In a phase 2 feasibility trial, hydroxyurea plus tadalafil was compared to hydroxyurea plus placebo for this indication[1].