The therapeutic concentration is from 8.2 to 24.6 mg (100 to 300 micromoles) per liter.

Vancomycin must be administered orally because intravenous administration does not achieve gut lumen minimum therapeutic concentration.

Phenytoin elimination kinetics show mixed-order behaviour at therapeutic concentrations.

In this case it is administered sublingually and reaches a therapeutic concentration after around 12 minutes.

Narrow therapeutic range (difference between toxic and therapeutic concentrations)

In long-term use, therapeutic concentrations of lithium have been thought to cause histological and functional changes in the kidney.

Unlike other psychoactive drugs, Li typically produces no obvious psychotropic effects (such as euphoria) in normal individuals at therapeutic concentrations.

Binding to these receptors only occurs at a higher than therapeutic internal concentration: 8-16 g kg.

Unfortunately for its therapeutic uses, the therapeutic concentration is very close to the toxic concentration.

Isoniazid reaches therapeutic concentrations in serum, cerebrospinal fluid, and within caseous granulomas.