To : Linda V. Re : Antiulcer medications While it is true that Zantac(ranitidine) and Tagamet(cimetidine) have rather high milk:plasma ratios, this is a prime example when the absolute amount of medication transferred to the infant is far far lower than a clinically relevant dose. The amount of Zantac and Tagamet reaching the infant is miniscule. But if the doctor is hesitant, i have enclosed monographs below on Pepcid and Axid that have good kinetics as far as breastfeeding is concerned. Pepcid is a better product anyway. Regards Tom Hale ------------------------------- Famotidine Fax # 1182 Trade: Pepcid Uses: Reduces gastric acid secretion AAP: Not reviewed Famotidine is a typical Histamine-2 antagonist that reduces stomach acid secretion. In one study of 8 lactating women receiving a 40 mg/day dose, the peak concentration in breast milk was 72 µg/L and occurred at 6 hours post-dose. The milk:plasma ratios were 0.41, 1.78, and 1.33 at 2, 6, and 24 hours respectively. These levels are apparently much lower than other histamine H-2 antagonists (ranitidine, cimetidine) and make it a preferred choice. Adverse Effects: Headache, constipation, increased liver enzymes AHL= 2.5-3.5 hours M/P= 0.41-1.78 PHL= PB = 17% PK = 1-3.5 hours Oral= 40% References: 1. Courtney TP, Shaw RW, et.al. Excretion of famotidine in breast milk. Br.J.Clin.Pharmacol. 26:639, 1988. 2. Echizen H & Ishizaki T: Clinical pharmacokinetics of famotidine. Clin Pharmacokinet 1991; 21:178-194. ------------------------------------------------ Nizatidine Fax # 1317 Trade: Axid Uses: Reduces gastric acid secretion AAP: Not reviewed Nizatidine is an antisecretory, histamine-2 antagonist that reduces stomach acid secretion. In one study of 5 lactating women using a dose of 150 mg, milk levels of nizatidine were directly proportional to circulating maternal serum levels, yet were very low. Over a 12 hour period 96 up (less than 0.1% of dose) was secreted into the milk. No effects on infants have been reported. Adverse Effects: Headache, GI distress AHL= 1.5 hours M/P= PHL= PB = 35% PK = 0.5-3 hours Oral= 94% References: 1. Obermeyer BD, Bergstrom RF, Callaghan JT, et.al. Secretion of nizatidine into human breast milk after single and multiple doses. Clin.Pharmacol.Ther. 47:724-30,1990.