Tretinoin Other names: ATRA Retinoic Acid All-trans retinoic acid

Tretinoin is indicated for topical application in the treatment of acne vulgaris. The safety and efficacy of the long-term use of this product in the treatment of other disorders have not been established.

Tretinoin is indicated in combination with arsenic trioxide or chemotherapy for the treatment of patients with acute promyelocytic leukaemia (APL) which is newly diagnosed, relapsed or refractory to chemotherapy.

Combination of tretinoin with chemotherapy or arsenic trioxide is known to be effective and to induce very high rates of haematologic remission in patients with genetically confirmed APL, i.e. patients whose blasts harbor the t(15;17) by karyotyping or FISH or the PML-RARa fusion as detected by PCR. Thus, genetic confirmation of diagnosis is mandatory. Combination treatment with arsenic trioxide has been shown an effective treatment option in patients with newly diagnosed low-to-intermediate risk APL. However, because APL is characterized by high risk of early haemorrhagic death, current recommendations dictate that early treatment with tretinoin is started as soon as possible upon morphologic suspicion only.

For the selection of treatment strategy the relapse risk – indicated by pre-therapeutic white blood cell count (WBC) and platelet count (Sanz score) with high-risk (WBC>10 × 10^9^/L), intermediate risk (WBC≤10 × 10⁹/L, platelet count ≤40 × 10⁹/L), and low risk (WBC≤10x10⁹/L, platelet count >40 × 10⁹/L) - should be taken into consideration.