Of the myriad of drugs approved by the FDA and used clinically, there are relatively few that clinical laboratories routinely monitor. The four major classes of drugs that TDM frequently monitors are:
- Antibiotics
- Anticonvulsants
- Immunosuppressants
- Cardiac medications
Other drugs monitored by TDM are not included in the above classifications. Still, the vast majority of TDM testing is performed for drugs that are included in one of these four categories.