, hyperthyroidism . Clearance of the drug is decreased in these conditions: elderly, acute congestive heart failure, cirrhosis, hypothyroidism and febrile viral illness. The elimination half-life varies: 30 hours for premature neonates, 24 hours for neonates, 3.5 hours for children ages 1 to 9, 8 hours for adult non-smokers, 5 hours