Neonatal/Pediatric Pharmacology Fred Hill, MA, RRT

Special Considerations Effects on developing fetus Special susceptibilities in neonates and children for certain drugs ~25% of drugs are labeled as safe and effective for children

Placental Drug Transfer How easily does a drug pass through the placental barrier? What are known effects of drugs on fetus? –Teratogens: drugs which are likely to cause physical/mental developmental abnormalities: spontaneous abortion, congenital malformations, intauterine growth retardation, mental retardation, carinogenesis. –First trimester most critical time of avoidance.

Thalidamide & Teratogenesis Had been considered drug of choice for morning sickness in pregnant women Thalidamide: s, >40,000 birth defects, 17 in U.S.

FDA Hero Chemie Gr Ü enthal attempted introduction of thalidomide into U. S. in 1961 Frances Kelsey repeatedly denied application.

Some Other Teratogens Alcohol: IUGR, microcephaly, dysmorphic facies, cleft palate, cardiac anomalies ACE inhibitors (captopril, enalapril, Lisinopril): hypotension, oliguria with renal failure, hyperkalemia, complications of oligohydramnios Carbamazepine: neural tube defects Cocaine: abruptio placentae, prematurity, microcephaly, limb defects, etc. Coumarin anticoagulents Diethylstilbestrol Lithium Misoprostol Tetracyclines: yellow-brown discoloration of teeth during calcification of teeth after 17 th week

Special Neonatal/Pediatric Applications Ribavirin: Anti-viral given by aerosolization for RSV. Potential for teratogenicity Indomethacin: close patent ductus arteriosis (PDA), may help prevent IVH Ibuprofen lysine (Neo Profen): close patent ductus arteriosis (PDA) Alprostadil-Prostaglandin E 1 (PGE 1 ): maintain PDA in certain heart defects Tolazoline: persistent pulmonary hypertension of the newborn Methylxanthines (theophylline & caffeine): neonatal apnea

Assessment of Oxygenation/Ventilation Fred Hill, MA, RRT

Sites of ABG Samples Umbilical artery catheter (UAC): preferred source Radial artery Brachial artery Simultaneous UAC and right radial sample when R → L shunting suspected Capillary samples (CBG) in place of ABG: useful for pH and PCO 2

Umbilical Artery Catheter

“Heel Stick”

Transcutaneous Monitoring Especially useful in neonates May not correlate with ABG values Useful for trending. Many factors affect values Thermal injury the major problem –Maximum temperature = 44 o C –Change sites periodically –Greater problem with premature infants