| Class | Dopamine receptor antagonist |
|---|---|
| Chemistry |
Benzamide |
| Routes of administration |
Oral, IV, IM, s/c |
| Absorption |
Rapidly and completely absorbed, bioavailability ~ 80% |
| Solubility |
pKa 9.27, highly water soluble |
| Distribution |
VOD = 3.5L/kg; minimally protein-bound (13-22%) |
| Metabolism |
Undergoes some hepatic metabolism, mainly by CYP 2D6 |
| Elimination |
About 20-50%of the drug dose is eliminated unchanged |
| Time course of action |
Half-life is about 4-6 hours, but the duration of antiemetic effect is only 1-2 hours |
| Target receptor |
D2 dopamine receptor antagonist (Gi-protein coupled); |
| Mechanism of action |
Antiemetic/antinausea effect is mainly exerted by the antidopaminergic effects centrally. Side effects (eg. dystonic reaction and galactorrhoea) are also mainly antidopaminergic. Prokinetic effects are mainly due to the peripheral muscarinic agonist effects |
| Clinical effects |
- Increased lower oesophageal sphincter tone |
| Literature reference |
Albibi et al, 1983 |
| CICM details of understanding | Level 3 |
| Mentioned around Deranged Physiology | |
| Related SAQs |
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