Efaproxiral

**Semantic type:** Pharmacologic Substance

**Definition:** A synthetic small molecule with radiosensitizing activity. Efaproxiral increases oxygen levels in hypoxic tumor tissues by binding non-covalently to the hemoglobin tetramer and decreasing hemoglobin-oxygen binding affinity. Increasing tumor oxygenation reduces tumor radioresistance. (NCI04)

**Synonyms:** - RSR13