Final answer:
Metoclopramide works by blocking dopamine receptors in the brain and increasing the release of acetylcholine, improving the motility of the upper gastrointestinal tract. Its clinical uses include treating GERD, delayed gastric emptying, and nausea/vomiting. Potential toxicities of metoclopramide include extrapyramidal symptoms, tardive dyskinesia, and sedation/drowsiness.
Step-by-step explanation:
Mechanism of Action:
The mechanism of action of metoclopramide involves its ability to block dopamine receptors in the brain and increase the release of acetylcholine. This leads to enhanced motility and coordination of the muscles in the upper gastrointestinal tract, improving the movement of food through the stomach and intestines.
Clinical Uses:
- Gastroesophageal Reflux Disease (GERD): Metoclopramide can be used to relieve symptoms of GERD, such as heartburn and regurgitation, by improving the movement of food from the stomach to the intestines.
- Delayed Gastric Emptying: It is also prescribed to stimulate stomach contractions and speed up the emptying of food in conditions like diabetic gastroparesis.
- Nausea and Vomiting: Metoclopramide is effective in reducing nausea and vomiting caused by chemotherapy, radiation therapy, and surgery.
Toxicities:
Although metoclopramide is generally well-tolerated, it can have some potential toxicities:
- Extrapyramidal Symptoms (EPS): These are movement disorders such as muscle stiffness, tremors, and involuntary movements that can occur with metoclopramide use, particularly at higher doses or with long-term use.
- Tardive Dyskinesia: In rare cases, prolonged use of metoclopramide can lead to tardive dyskinesia, characterized by involuntary repetitive movements such as lip smacking, chewing, or tongue protrusion.
- Sedation and Drowsiness: Metoclopramide may cause drowsiness or sedation in some individuals, which can impair alertness and concentration.