Table 1.
Characteristics of cholinesterase inhibitors
| Cholinesterase inhibitors | |||
|---|---|---|---|
| Characteristic | Donepezil | Rivastigmine | Galantamine |
| Trade name | Aricept (Aricet in some countries) | Exelon | Razadyne and Razadyne-ER |
| Indications | Mild to moderate and severe AD | Mild to moderate AD; Parkinson’s disease dementia | Mild to moderate AD |
| Half-life | 70 hours | 1.5 hours (brain half-life is 8 hours) | 7 hours |
| Administration schedule | q.d. | b.i.d. for capsules; q.d. for the patch | b.i.d. for the non-ER form: q.d. for the ER form |
| Metabolism by hepatic CYP enzymes | 2D6, 3A4 | No | 2D6, 3A4 |
| Protein binding | 96% | 40% | 18% |
| Bioavailability | 100% | 40% | 90% |
| Time to peak serum level | 3–4 hours | 1 hour | 1 hour (2.5 hours with food); 4.5 hours for ER form |
| Absorption delayed by food | No | No | Yes (1 hour to 2.5 hours) |
| Titration | Begin with 5 mg and advance to 10 mg after 1 month | Oral form: 1.5 mg b.i.d. for 4 weeks; 3 mg b.i.d. for 4 weeks; 4.5 mg b.i.d. for 4 weeks; advance to 6 mg b.i.d. if tolerated Patch form: begin the 5 cm2 patch for 1 month then advance to 10 cm2 patch |
Non-ER form: begin 4 mg b.i.d.; advance to 8 mg b.i.d. after 1 month and to 12 mg b.i.d. after 1 month ER form: begin at 8 mg q.d.; advance after 1 month to 16 mg DQ and after 1 month to 24 mg q.d. |
Tacrine (Cognex) is now rarely used because of associated liver enzyme elevations and is not included in this chart.