What is Contromet? An Overview
Contromet is a brand name for the medication metoclopramide, specifically known by the trademarked name Adco-Contromet in some regions. The active ingredient is metoclopramide monohydrochloride. Metoclopramide is a prescription-only drug that belongs to a class of medications known as dopamine receptor antagonists. It is considered both an antiemetic, meaning it helps prevent and relieve nausea and vomiting, and a prokinetic agent, which means it helps regulate and increase the movement of the digestive tract.
While the brand name Contromet may be less familiar in some countries like the United States, the generic metoclopramide and other brand names like Reglan are widely known. The medication is available in various forms, including tablets, syrups, and injections.
How Contromet (Metoclopramide) Works
The dual mechanism of action is what makes metoclopramide effective for a range of gastrointestinal issues. It works on both the central nervous system (CNS) and the peripheral nervous system (PNS).
The Dual Mechanism of Action
- Antiemetic Effect: In the brain, metoclopramide blocks dopamine D2 receptors in the chemoreceptor trigger zone (CTZ), an area that sends signals to the vomiting center of the brain. By blocking these signals, it effectively suppresses the sensation of nausea and prevents vomiting.
- Prokinetic Effect: In the gut, metoclopramide increases the amplitude, frequency, and duration of gastric contractions. It also helps relax the pyloric antrum and duodenal cap, speeding up the passage of food from the stomach to the intestine. This accelerated gastric emptying helps relieve symptoms such as heartburn, bloating, and feelings of fullness.
Common Uses of Contromet
Contromet (metoclopramide) is prescribed for a variety of conditions related to digestive and motility issues. The primary indications include:
- Diabetic Gastroparesis: This condition causes delayed stomach emptying in people with diabetes, leading to symptoms like nausea, vomiting, and bloating. Contromet is used for 2 to 8 weeks to manage these symptoms.
- Gastroesophageal Reflux Disease (GERD): For patients whose symptoms are not adequately controlled by other treatments, metoclopramide can help alleviate heartburn by improving gastric emptying. Treatment duration typically ranges from 4 to 12 weeks.
- Chemotherapy-Induced Nausea and Vomiting (CINV): It is effective in preventing and treating nausea and vomiting associated with cancer chemotherapy.
- Post-operative Nausea and Vomiting (PONV): The medication can be used to prevent and treat nausea following surgery.
- Radiographic Examinations: In some cases, it can be used to speed up gastric emptying to facilitate X-ray examinations of the stomach and duodenum.
Important Risks and Side Effects
The use of Contromet is associated with a black box warning from the FDA concerning the risk of tardive dyskinesia (TD), a potentially irreversible movement disorder. This risk increases with the duration of treatment and the total cumulative dose, leading to the recommendation that metoclopramide therapy should not exceed 12 weeks.
Comparing Contromet to Other Anti-Nausea Drugs
| Feature | Contromet (Metoclopramide) | Ondansetron (Zofran) | Promethazine (Phenergan) |
|---|---|---|---|
| Drug Class | Dopamine antagonist, prokinetic | Serotonin 5-HT3 receptor antagonist | H1 antagonist, sedative |
| Mechanism | Blocks dopamine in the brain's CTZ and increases GI motility | Blocks serotonin receptors, primarily in the CTZ and gut | Blocks histamine receptors; also has central anti-dopaminergic action |
| Key Side Effect | Tardive dyskinesia (black box warning) | Headache, constipation, QTc prolongation | Sedation, dizziness, blurred vision |
| Typical Duration | Short-term (up to 12 weeks) due to TD risk | As needed or short course during chemo | As needed or short course |
| Effect on Motility | Increases GI motility (prokinetic) | No significant effect on motility | Can decrease GI motility (anticholinergic) |
| Use in Pregnancy | Avoid in first and third trimesters if possible | Generally considered safer; common for morning sickness | Can cause respiratory depression in infants if given near birth |
Other Side Effects
In addition to tardive dyskinesia, other side effects of metoclopramide can include:
- Drowsiness, fatigue, and restlessness.
- Extrapyramidal symptoms (EPS) like muscle spasms, tremors, and twitching.
- Diarrhea.
- Depression, anxiety, and confusion.
- Less common but serious: Neuroleptic Malignant Syndrome (NMS).
Dosage, Administration, and Precautions
Patients should always follow a doctor's instructions for using Contromet. Due to the risk of TD, it is crucial to use the medication only as prescribed and for the shortest duration possible.
- Typical Dosage: The standard adult dose is 10 mg, taken up to three or four times daily, typically 30 minutes before meals and at bedtime.
- Duration: Therapy should be limited to short-term use, generally not exceeding 5 days for nausea and vomiting, and capped at 12 weeks for chronic conditions like gastroparesis.
- Monitoring: Dosage may need adjustment for those with kidney or liver problems and for elderly patients.
- Alcohol: Concomitant use with alcohol should be avoided as it can increase the sedative effects of the drug.
Who Should Avoid Contromet?
Certain individuals should not take Contromet due to the risk of serious complications:
- Those with gastrointestinal obstruction, perforation, or hemorrhage.
- Patients with a history of tardive dyskinesia or other movement disorders.
- People with a history of convulsive disorders or epilepsy.
- Patients with phaeochromocytoma, a tumor of the adrenal gland.
- Individuals with Parkinson's disease, as the drug can worsen symptoms.
- Patients with a history of depression, as metoclopramide can cause depression.
Conclusion: Navigating Treatment with Contromet
Contromet, the brand name for metoclopramide, is a valuable prescription medication for short-term treatment of nausea, vomiting, gastroparesis, and GERD. Its unique dual action on both the brain and the digestive tract makes it an effective antiemetic and prokinetic agent. However, its use is strictly regulated and limited to short courses due to the serious, dose-dependent risk of irreversible tardive dyskinesia. Alternatives exist for both acute and chronic nausea, and treatment decisions should always be made in careful consultation with a healthcare provider who can weigh the potential benefits against the significant risks. Patients must be vigilant in monitoring for side effects and adhere strictly to prescribed dosages and durations. For comprehensive professional information, the Drugs.com monograph on metoclopramide provides in-depth details regarding its pharmacology, dosing, and precautions.
