Levothyroxine has a narrow therapeutic index Over or undertreatment may have negative effects on growth and development, cardiovascular function, bone metabolism, reproductive function, cognitive function, emotional state, gastrointestinal function, and on glucose and lipid metabolism in adult or pediatric patients In pediatric patients with congenital and acquired hypothyroidism, undertreatment may adversely affect cognitive development and linear growth, and overtreatment is associated with craniosynostosis and acceleration of bone age Titrate dose carefully and monitor response to titration to avoid these effects; consider potential for food or drug interactions and adjust administration or dosage as needed Some of the Br mouse strains enable the expression of a much greater number of possible color combinations since multiple copies of the cassette were integrated into their genome 16
