Autoinduction of biotransformation and action as a hormone is seen in:

Ans: D (Thyroxine) Ref: Basic and Clinical Pharmacology by Katzung, 2012. 12th ed. Pg 684-685Explanation:In hyperthyroidism, the half lives of T3 and T4 are decreased owing to their enhanced metabolic clearance.Similarly in hypothyroidism, the half lives of T3 and T4 are increased due to reduced metabolic clearance. This clearly shows the autoinduction feature of thyroid hormones.In hyperthyroidism, the required dose of digoxin increases while in hypothyroidism lower dose is sufficient.Sedation and respiratory depression is more with sedatives and opioids respectively in patients w ith hypothyroidism w hile these effects are less in hyperthyroidism.