Self-assessment

Abstract

A 9-day-old neonate (3.4 kg) born at 36 weeks gestation was born presenting with irritability, hypoglycaemia and mild jaundice. Blood cultures were taken and showed the neonate had a Group B streptococcal infection and was started on IV benzylpenicillin and gentamicin. The neonate also developed seizures associated with hypoxia a few hours after birth and was loaded with IV phenobarbitone 68 mg (20 mg/kg/dose) and was then prescribed a maintenance dose of oral phenobarbitone 8.5 mg twice daily (2.5 mg/kg). The neonate started to experience breakthrough seizures a few days after starting the oral phenobarbitone and a trough level was reported at 12 mg/L (15–25 mg/L). The dose was then increased to 12 mg twice daily (3.5 mg/kg) and the seizures became controlled.1.Which physiological factors in a neonate would lead to reduced bioavailability of the oral phenobarbitone? Select ONE answera.High gastric pHb.Increased gastric emptying timec.Increased intestinal surface aread.Increased first pass metabolism2.Which physiological factor in the neonate would increase the volume of distribution of phenobarbitone? Select ONE answera.Decreased cardiac output and tissue perfusion compared to an older childb.Decreased binding affinity for albuminc.Higher total body water and lower fat composition compared to adultsd.Immature carrier-mediated transport systems3.Which physiological factor in the neonate would affect elimination of phenobarbitone? Select ONE answera.Increased liver enzyme systems and decreased renal clearanceb.Increased liver enzyme systems and increased renal clearancec.Decreased liver enzyme systems and decreased renal clearanced.Decreased liver enzyme systems and increased renal clearance