<prompt> Which of the following drugs require therapeutic drug monitoring?MetforminPropranololWarfarinPhenytoin  <response>: Therapeutic drug monitoring is adjustment of dose of the drug according to its plasma concentration. It is required for A Aminoglycosides e.g. gentamicin Drug Digitalis Possessing Phenytoin anti-epileptics Low Lithium Therapeutic Tricyclic antidepressants Index Immunomodulators e.g. cyclosporine 