Quinidine

Specimen:

5 mL blood in plain tube, collected as trough level immediately prior to next dose.

Method:

Chromatography, fluorometry, immunoassay.

Therapeutic Interval:

7-15 µmol/L (2.3-4.8 mg/L).

Application:

24 to 48 h should elapse prior to retesting after dose adjustment. Mean half-life 7 h (range 4-12 h).

Interpretation:

Level must be related to time since last dose.

Reference:

Ochs HR et al. Clin Pharmacokinet. 1980; 5: 150-168.