Plasma retinol levels and side effects following high-dose retinyl acetate in breast cancer patients.
Plasma retinol levels and toxicity were evaluated in thirteen metastatic breast cancer patients treated orally with high-dose (300,000 I.U./day) retinyl acetate in combination with oral tamoxifen. Following the first dose of the drug, there was a drop of plasma retinol concentrations followed by a recovery to the pre-treatment levels and by a further increase to reach a plateau six to eight hours after drug administration. During the first two months of treatment cumulative increase of plasma retinol was seen, and long-term systemic concentrations in the +50-60% range level were maintained by the treatment. The toxicity observed was acceptable and included gastrointestinal symptoms, skin toxicity and headache. These toxicities could be related to the long-term increase of retinol systemic concentrations. We concluded that the daily dose of 300,000 I.U. retinyl acetate can be administered to cancer patients over a period of several months, is well tolerated and yields a substantial increase of systemic retinol.
Resasco
M
M
Servizio di Farmacologia, Instituto Nazionale per la Ricerca sul Cancro, Genova, Italy.
Canobbio
L
L
Trave
F
F
Valenti
G
G
Mazzoni
A
A
Canti
G
G
Boccardo
F
F
Nicolin
A
A
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000097:blood / Q000188:drug therapy*; D004224:Diterpenes; D005260:Female; D006801:Humans; D000084562:Retinyl Esters; D013629:Tamoxifen / Q000008:administration & dosage / Q000627:therapeutic use; D014801:Vitamin A / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000097:blood* / Q000627:therapeutic use
D004224:Diterpenes; D000084562:Retinyl Esters; D013629:Tamoxifen; D014801:Vitamin A; C009166:retinol acetate