Therapeutic drug assays

TDL’s therapeutic drug assays measure the serum level of a drug to ensure its concentration is within the therapeutic range.

There are three different collection times for Therapeutic Drug Monitoring:

• Trough Level: Blood should be collected just before the next dose. Trough Levels check that the appropriate drug concentration is being maintained.
• Peak Levels: Sample collection time is dependent on specific drug type and method of administration. Peak levels check that the drug level is not in the toxic range.
• Suspected Toxicity: Blood can be collected any time.

All collections should have the following noted on the request form:

• Dosage schedule including the amount and frequency and time of the last dose
• Time of specimen collection
• Clinical status of patient (e.g. routine, suspected toxicity)
• Name(s) of other drugs being taken by the patient