Infants phenytoin

A 27-year-o d woman with epilepsy has been taking phenytoin to control her seizures. She is now pregnant, and her physician is considering changing her medication to prevent potential bleeding episodes in the in nt. What biochemical activity might be deficient in the infant if her medication is continued ... 

Er hromycin Sulfisoxazole (Eryzole, Pediazole) [Anti-infective, Macrolide/Sulfonamide] Uses Upper lower resp tract bacterial Infxns H. influenzae otitis media in children Infxns in PCN-allergic pts Action Macrolide antibiotic w/ sulfonamide Dose Adults. Based on erythromycin content 400 mg erythromycin/1200 mg sulfisoxazole PO q6h Feds > 2 mo. 40-50 mg/kg/d erythromycin 150 mg/kg/d sulfisoxazole PO -s- q6h max 2 g/d erythromycin or 6 g/d sulfisoxazole x 10 d in renal impair Caution [C (D if near term), +] w/ PO anticoagulants, hypoglycemics, phenytoin, cyclosporine Contra Infants <2 mo Disp Susp SE GI upset Additional Interactions T Effects of sulfonamides W/ ASA, diuretics, NSAIDs, probenecid EMS See Erythromycin OD See Erythromycin... 

Phenytoin Moderate Amounts entering breast milk are not sufficient to cause adverse effects in infant. 

Mebendazole Accidental mebendazole poisoning in infants is associated with convulsions, respiratory arrest, and tachyarrhythmia.181 If administered concomitantly, mebendazole interacts with phenytoin, carbamazepine, and cimetidine. 

A 15-month-old infant developed seizures (132). Her heart rate was 200/minute, here peripheries were cya-nosed, and she had labored breathing, dilated pupils reacting sluggishly to light, and a temperature of 37.3° C. There was a rash over the right iliac fossa. Her neck and back were arched. Her liver was enlarged. There was no response to rectal diazepam, rectal paraldehyde, or intravenous lorazepam, but she responded to phenytoin and anesthesia with thiopental and suxamethonium. Amphetamine was detected in her urine. 

Loughnan PM, Greenwald A, Purton WW, et al. 1977) Pharmacokinetic observations of phenytoin disposition in the newborn and young infant. Arch Dis Child 52 302-309. 

The major route of elimination is hepatic metabolism. The variability in the metabolism and pharmacokinetics in neonates, infants and children necessitates monitoring of drug concentrations in the plasma, particularly when it is co-administered with phenytoin, phenobarbital or rifampin. 

Antiepilepsy. General note of caution observe the infant for sedation and poor suckling. Primidone, ethosuximide and phenobarbital are present in milk in high amounts phenytoin and sodium valproate less so. 

A mother with eclampsia was unsuccessfully treated with diazepam, total dose 120 mg, and phenytoin 750 mg she received thiopental and had an emergency cesarean section at 33 weeks gestation (12). The infant was unresponsive and floppy, requiring intubation and ventilation. At 10 hours after delivery a flumazenU infusion was begun the baby responded with facial and limb movements within 30 seconds, resumed spontaneous ventilation, and was extubated 4 hours later. She was maintained on a slowly reducing flumazenil infusion over the next 4 days while the benzodiazepines were metabolized. 

Plasma hexachlorophene levels have not been demonstrated to correlate well with clinical effects. Hexachlorophene may cause seizures. The risk of seizures during emesis may preclude the use of ipecac syrup. Charcoal slurry, aqueous or mixed with saline cathartic or sorbitol, should be administered. The usual charcoal dose is 30-100 g in adults and 15-30 g in children (1 or 2 g kg in infants). If seizures cannot be controlled with diazepam or they recur, phenytoin or... 

Metabolism of drugs such as theophyUine, phenobarbital, and phenytoin by oxidation is also impaired in newborn infants. The rate of metabolism, however, is more rapid with phenobarbital and phenytoin than with theophylline, perhaps owing to the involvement of different cytochrome P450 isozymes. Total clearance of phenytoin by CYP2C9 and to a lesser extent by C YP2C19 surpasses adult values by 2 weeks... 

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