Therapeutic Drug Monitoring

This test is used to determine the dosage size and timing that will be safest and most effective for the patient, while avoiding potential complications from drug interactions. There are several categories of drugs that require monitoring:

Antibiotics

Used to treat infections with bacteria that are resistant to less toxic antibiotics. Includes aminoglycosides (gentamicin, tobramycin, amikacin) Vancomycin, Chloramphenicol.

Antiepileptics

Used to treat epilepsy, prevention of seizures. Includes phenobarbital, phenytoin, valproic acid, carbamazepine, ethosuximide, sometimes gabapentin, lamotrigine.

Anti-cancer drugs

Used to treat various cancers, rheumatoid arthritis, non-hodgkin's lymphomas, osteosarcoma, psoriasis. Includes methotrexate.

Bronchodilators

Used to treat asthma, Chronic obstructive pulmonary disorder (COPD), neonatal apnea. Includes Theophylline, caffeine.

Cardiac drugs

Used to treat congestive heart failure, angina, arrhythmias. Includes digoxin, quinidine, procainamide, N-acetyl-procainamide (a metabolite of procainamide).

Immunosuppressants

Used to prevent rejection of transplanted organs. Includes cyclosporine, tacrolimus, sometimes sirolimus, mycophenolate mofetile.

Psychiatric drugs

Used to treat bipolar disorder (manic depression), depression. Includes lithium, desipramine, some antidepressants (imipramine, amitriptyline, nortriptyline, doxepin).

Therapeutic Drug Monitoring (TDM) FAQs

How do I prepare?

Prior to having your blood drawn for a drug level test, find out if you are expected to take the drug before or after your test, as this could affect the result.

What if I forget the instructions?

If you forget and, for example, take the drug when you are supposed to wait, let someone in the doctor’s office or lab know before your blood is drawn.

How does the doctor decide how much drug to prescribe?

Everyone processes medications differently, depending on many factors. These may include your weight, age, temperature, body composition, as well as gastric and cardiac conditions and other physiological factors.

What should I do if I forget to take my medication on time?

Do not double your dose the next time. Consult your doctor or pharmacist.

Can I monitor myself?

No. There is specific timing for drawing blood and highly advanced laboratory equipment is used to determine the most accurate result.