<prompt> Which is not true for therapeutic drug monitoring TDM?Done when clinical response can be easily measuredDone for narrow therapeutic index drugsDigoxin is an example of a drug for which TDM is doneTDM can be done if drug has erratic pharmacokinetics  <response>: Criteria for doing TDM Low therapeutic index When therapeutic response cannot be easily measured Inconsistent pharmacokinetics of the drug TDM is done for A Aminoglycosides Drug Digoxin Possessing Phenytoin Very Valproate Low Lithium Therapeutic Tricyclic Antidepressants Index Immunosuppressants 