A patient presents with nephrotic syndrome and hypoalbuminemia. Action of which of the following drug is NOT affected by this condition?
Only 35% of morphine is bound to albumin in normal subjects, so reduction in protein level is not going to affect the action of the drug. Only the fraction of drug that is not bound to proteins is available to produce its pharmacological actions. Changes in protein binding can be impoant, but only if: The propoion of a drug that is bound to protein is high. The drug is not widely distributed to the tissues. If a drug is widely distributed any increase in unbound drug in the plasma will rapidly be mopped up by the tissues. Drugs which are heavily protein bound: CNS drugs: Chlordiazepoxide, chlorpromazine, amitriptyline, indomethacin, valproic acid, diazepam, imipramine, phenytoin, phenylbutazone. Other drugs: Warfarin, sulphamethoxazole, tolbutamide. Ref: Practical Management of Pain edited by P. Prithvi Raj page 464. Pharmacology, 2/e By Bhattacharya page 20.
Tolbutamide
Morphine
Diazepam
Valproate