Drug Levels Test

Many medications can be assayed in the blood to determine whether the level is high enough to have a therapeutic effect, or whether it may be too high, resulting in toxic side-effects. Your doctor may use a drug level to adjust the medication dose or dosing schedule.

How the Test is Performed

Drug levels are taken on a sample of blood from a vein.

Medical Conditions and Symptoms

Drug levels are usualy requested to check whether a drug dose needs to be adjusted, or to determine whether the level of the drug in the bloodstream is too high or too low.

Test Results Explained

When the level is within the therapeutic range, between the lower value and the higher value of the laboratory reference range, the dose is usually correct, but it is possible to get symptoms, side effects, or inadequate control of symptoms within this range and the dose may need to be adjusted according to your doctor’s clinical assessment.

Related Specialists

Related Procedures

Blood Test (venesection)

Related Tests

Phenytoin level
Carbamazepine level
Valproate level
Digoxin level
Lithium level
Theophylline level
Paracetamol level
Salicylate level
Iron level

Also Known As

Therapeutic drug levels