Carbamazepine
| Therapeutic range | Approximate time to steady state | Sampling time |
| 4-12 mg/L | 14-28 days after starting therapy 2-4 days after a dose change |
Pre-dose |
Digoxin
| Therapeutic range | Approximate time to steady state | Sampling time |
| 0.8-2.0 mcg/L | 7 Days | At least 6 hours post dose |
Lithium
| Therapeutic range | Approximate time to steady state | Sampling time |
| 0.4-1.0 mmol/L | 4-7 days | 12 hours after evening dose |
Phenobarbital
| Therapeutic range | Approximate time to steady state | Sampling time |
| 15-40 mg/L | 14-28 days | Pre-dose |
Phenytoin
| Therapeutic range | Approximate time to steady state | Sampling time |
| 10-20 mg/L | 7-28 days (varies considerably between patients | Pre-dose |
Theophylline
| Therapeutic range | Approximate time to steady state | Sampling time |
| 10-20 mg/L | 2 days | m/r preps, 4-6 hours post-dose |
Aminophylline Infusion
| Therapeutic range | Approximate time to steady state | Sampling time |
| 10-20 mg/L | 1 day | Sampling time not critical |