Spontaneous or imposed circadian changes in plasma concentrations of 5-fluorouracil coadministered with folinic acid and oxaliplatin: relationship with mucosal toxicity in patients with cancer.
Clin Pharmacol Ther
; 56(2): 190-201, 1994 Aug.
Article
em En
| MEDLINE
| ID: mdl-8062496
ABSTRACT
Pharmacokinetics of total platinum, 5-fluorouracil, l-folinic and d-folinic acid, and 5-methyltetrahydrofolate were studied in plasma from nine patients with advanced colorectal cancer treated with oxaliplatin (20 mg/m2/day), 5-fluorouracil (600 mg/m2/day), and folinic acid (300 mg/m2/day). Drugs were administered with a programmable-in-time pump by continuous infusion for 5 days. We compared two drug delivery schedules constant rate versus chronomodulated rate with peak of oxaliplatin at 4 pm and peak of 5-fluorouracil and folinic acid at 4 am. In the chronomodulated schedule, plasma concentrations of the drugs paralleled the pump functioning maximum platinum concentration near 4 pm, and maximum 5-fluorouracil and folate concentrations near 4 am. When drugs were administered at a constant rate, mean plasma concentration of 5-fluorouracil varied in a circadian manner each treatment day, that is, a peak at 4 am (approximately 800 ng/ml) and a trough at 1 pm (approximately 100 ng/ml). Mean plasma levels of total platinum and folate compounds increased over the first 24 hours. Total platinum mean level and that of the inactive d-folinic acid isomer reached a constant plasma concentration, whereas biologically active folates exhibited circadian variation in their plasma concentrations (peak around 7 am, trough near 6 pm, and amplitude approximately 10%). Severe mucositis was exhibited by all four patients on the flat schedule, but only by one on the chronomodulated schedule (p < 0.008). Individual pharmacokinetic and toxicity data showed that patients with circadian rhythms in 5-fluorouracil concentrations were least sensitive to 5-fluorouracil-related toxicity. Thus amplification or induction of such rhythm in 5-fluorouracil exposure may permit dose escalation.
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Base de dados:
MEDLINE
Assunto principal:
Compostos Organoplatínicos
/
Neoplasias Colorretais
/
Protocolos de Quimioterapia Combinada Antineoplásica
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Leucovorina
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Ritmo Circadiano
/
Fluoruracila
Tipo de estudo:
Clinical_trials
Limite:
Adult
/
Aged
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Ano de publicação:
1994
Tipo de documento:
Article