Is there a genetic factor in flecainide toxicity?

Abstract

surgeries and have reported our early findings.2 We extended our study to include animals for slaughter. As Drs McCarthy and Zumla refer to the organism being difficult to culture it is appropriate to present our methods, which by using a selective medium make the isolation and recognition of DF-2 organisms comparatively easy. Cotton wool tipped swabs of incisor teeth and gingival margins were placed in Amies charcoal based transport medium for delivery to the laboratory, where they were cultured using brainheart infusion agar (Difco) containing horse blood 5%, cysteine hydrochloride 0 5 g/l, kanamycin 25 mg/l, and vancomycin 1 mg/l. Plates were incubated in 95% air and 5% carbon dioxide in 95% relative humidity at 37°C and examined after three and five days. Under these conditions DF-2 grew after three days as smooth grey convex, circular colonies about 2-3 mm in diameter. Gram stained smears showed pleomorphic Gram negative bacilli with tapering ends, filamentous organisms being commonly seen. The identity of suspected isolates was confirmed using methods similar to those of Weaver et aP3 with the addition of rapid enzyme tests. In addition to organisms that conformed to previous descriptions of DF-2 others were isolated that fermented glucose, maltose, lactose, sucrose, and usually raffinose and inulin. They are thus similar to the DF-2 like strains reported by Weaver et al.4 Altogether 469 swabs were collected from dogs, cats, and other animals; the table shows the results. Isolation of DF-2 and DF-2 like organisms from oral swabs of domestic animals. Values are numbers (percentages) DF-2 like DF-2 organisms Total isolated isolated Dogs 180 44 (24) 20(11) Cats 249 42 (17) 19 (8) Pigs 13 Sheep 12 3 (25) Cattle 15 5 (33)

Critical Aspects in the Preparation of Extemporaneous Flecainide Acetate Oral Solution for Paediatrics

“…This situation is reminiscent of that described by Stuart et al where the cause of intoxication was traced back to the crystallisation of Fl after storage in a refrigerator (unfortunately, the composition of the suspending vehicle was not reported) [19]. In fact, the administration of an aliquot of a solution containing floaters of concentrated Fl may result in over-dosing rather than under-dosing.…”

“…Although it is possible to administer the correct dose even from suspensions [17,18], it should be noted that the presence of a precipitate that has not been properly characterised could affect stability and bioavailability in unexpected ways. Indeed, the literature reports at least one case of intoxication due to the formation of Fl crystals [19].…”

Life-Threatening Flecainide Intoxication in a Young Child Secondary to Medication Error

“…Ventricular tachycardia occurred when milk feeds were substituted with dextrose feeds and the serum flecainide concentration increased from 0.99 to 1.824 µg/mL in 24 hours, demonstrating impaired absorption of oral flecainide secondary to milk feeds. Lastly, Stuart et al 12 reported on a neonate who developed flecainide toxicity after his liquid preparation was refrigerated, causing crystallization and inaccurate dosing.…”