Document Detail

Flecainide distribution, transplacental passage, and accumulation in the amniotic fluid during the third trimester of pregnancy.
MedLine Citation:
PMID:  7803877     Owner:  NLM     Status:  MEDLINE    
OBJECTIVE: To study the disposition of flecainide acetate and its transplacental passage (both into the fetus and in the amniotic fluid) during the third trimester of pregnancy. DATA SOURCES: Reference articles and books are identified in the text. A literature review is presented. CASE SUMMARY: Flecainide distribution, transplacental passage, and accumulation into the amniotic fluid were studied in a patient at term presenting with a fetal supraventricular tachycardia diagnosed at 33 4/7 weeks of gestation. The fetal tachycardia was accompanied by cardiac failure with placental anasarca and hydramnios. Flecainide 100 mg po bid was prescribed initially; by the time of delivery, the dosage had been decreased to 50 mg bid. At delivery day (39 5/7 weeks), the pharmacokinetics of total flecainide were studied at plateau. DATA SYNTHESIS: The concentrations of flecainide at birth in fetal and maternal blood and in amniotic fluid were 235.4, 241.2, and 6426.5 micrograms/L, respectively. Calculation of a fetomaternal blood accumulation ratio of 0.97 showed that, at this gestational age, flecainide penetrates the placental membrane easily without accumulation in fetal blood. In contrast, the concentration of flecainide in amniotic fluid was approximately 27-fold that measured in maternal peripheral blood. Our results suggest the following: (1) close to term, the metabolic clearance (fetal hepatic clearance) of flecainide offers a high yield and its excretion by the fetal kidney is efficient; (2) given that amniotic fluid is constantly swallowed, it seems that, in contrast to what is seen in adults (relative oral bioavailability > or = 95 percent), the oral bioavailability of flecainide is possibly low in the fetus at term or close to term; under such circumstances, the drug would accumulate passively within the gestational sac; and (3) an alternative explanation is that the concentration in the fetus is, in part, the result of both transplacental crossing of the drug and reabsorption orally from the amniotic fluid. CONCLUSIONS: The regular therapeutic monitoring of flecainide is necessary and sufficient in the mother as the concentrations found appear to accurately reflect the degree of fetal accumulation. Because previous studies in infants and children have indicated few toxic adverse effects attributed to flecainide, it appears that the risk to a sucking infant of ingesting toxic amounts of flecainide in human breast milk is very low. Finally, the child of the patient described here has normal initial growth and development at the present time. The transplacental penetration of a drug can be considered, according to gestational age and the disorder being treated, as being of no consequence, dangerous, or desirable. Flecainide appears to fall into this last category.
P Bourget; J C Pons; C Delouis; L Fermont; R Frydman
Related Documents :
2904307 - Enzyme analysis of amniotic fluid for prenatal diagnosis of cystic fibrosis in high-ris...
2812647 - Interrelationships among abnormal cardiotocograms in labor, meconium staining of the am...
20141627 - Bdnf val66met polymorphism and protein levels in amniotic fluid.
22721627 - Perturbed sperm-epithelial interaction in bitches with mating-induced endometritis.
15956767 - Prenatal alcohol exposure and fetal programming: effects on neuroendocrine and immune f...
7892867 - Limitations in the clinical prediction of intrapartum fetal asphyxia.
Publication Detail:
Type:  Case Reports; Comparative Study; Journal Article    
Journal Detail:
Title:  The Annals of pharmacotherapy     Volume:  28     ISSN:  1060-0280     ISO Abbreviation:  Ann Pharmacother     Publication Date:  1994 Sep 
Date Detail:
Created Date:  1995-02-02     Completed Date:  1995-02-02     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  9203131     Medline TA:  Ann Pharmacother     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1031-4     Citation Subset:  IM    
Laboratory of Pharmacology and Toxicology, Hôpital Antoine Béclère, Clamart, France.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Amniotic Fluid / metabolism*
Fetal Monitoring
Flecainide / pharmacokinetics*
Maternal-Fetal Exchange*
Placenta / metabolism
Pregnancy Trimester, Third
Reg. No./Substance:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Anaphylactoid reactions associated with ondansetron.
Next Document:  Neurologic sequelae associated with foscarnet therapy.