Metoclopramide Flashcards
Drugs - Pharmacology
1
Q
What is a Emesis?
A
The vomiting centre lies within midbrain and is activated when chemoreceptors within this area are triggered.
These receptors are associated with dopamine and Serotonin neuro-transmitters.
2
Q
Other names
A
Maxolon
3
Q
Class
A
Antiemetic
4
Q
Actions
A
Supresses CNS stimulation to reduce vertigo, nausea and GI tract emesis.
Dopamine receptor antagonist
5
Q
Indication
A
- Nausea or vomiting in adults >20yrs
- Prophylactic use in administration of opioids
- Effective in management of emesis in associated with gastroduodenal, hepatic and biliary disease.
6
Q
Presentation
A
Ampoule containing metoclopramide at 10mg/2ml
May come in 10mg tablet or oral solution on prescription
7
Q
Pharmacodynamic Action
A
- Inhibits effects of neurotransmitters Dopamine at receptor sites in midbrain = reduces nausea.
- In higher doses (5HT3 serotonin receptors), directly on the smooth muscle of GI tract increasing intestinal motility = reduces Emesis.
8
Q
Pharmacokinetic Action
A
- Absorption: Rapid with good bioavailability even after oral ingestion
- Distribution: Plasma with 30% protein binding
- Metabolism: Hepatic
- Elimination: 85% via renal urine
9
Q
Side effects
A
- drowsiness or restlessness
- cardiac conduction abnormalities (IV)
- Diarrhoea, rash
- extra-pyramidal effects
10
Q
Extra-pyramidal effects
A
- more common in children, young adults especially girls and very elderly
- extra-pyramidal moto tracts are neural fibres that transmit through midbrain
- affects on this tract result in involuntary movements, muscle rigidity and immobility without paralysis
