Generic Name and Brand

Reglan is the brand name for the drug metoclopramide. Metoclopramide is a dopamine antagonist used primarily in the treatment of gastrointestinal disorders. It is prescribed to manage conditions such as gastroparesis and gastroesophageal reflux disease (GERD).

Approved Indications

Metoclopramide is approved for the management of diabetic gastroparesis, which involves delayed stomach emptying. It is also indicated for the treatment of GERD, particularly when standard treatments fail. Additionally, it may be utilized as an antiemetic to prevent nausea and vomiting linked to chemotherapy or post-surgery.

Mechanism of Action

Metoclopramide works by blocking dopamine receptors in the brain and gut. This action enhances gastrointestinal motility and accelerates gastric emptying. It also increases the tone of the lower esophageal sphincter, reducing reflux symptoms.

Dosage Forms Available

Reglan is available in multiple forms including oral tablets, oral disintegrating tablets, and an injectable solution. Standard tablet strengths typically include 5 mg and 10 mg. The injectable form is primarily used in hospital settings for acute symptom management.

Recommended Dosage

For diabetic gastroparesis, the typical adult dose ranges from 10 mg to 15 mg, administered up to four times daily, 30 minutes before meals and at bedtime. For GERD, the dosage may be the same, but it is often tailored to individual needs and severity of symptoms. Dosage adjustments are necessary for renal impairment.

Drug Interactions

Concurrent use of metoclopramide with other dopamine antagonists may lead to an increased risk of extrapyramidal symptoms. Combining with MAO inhibitors may result in hypertensive reactions. Patients on CNS depressants need dose adjustments due to potential additive effects. Caution is advised when used with cyclosporine or digoxin due to altered pharmacokinetics.

Side Effect Profile

Common side effects include drowsiness, fatigue, and restlessness. Extrapyramidal symptoms such as tardive dyskinesia may occur with prolonged use. Less common effects involve neuroleptic malignant syndrome and depression. Proper monitoring is essential to minimize risks.

Contraindications

Metoclopramide is contraindicated in patients with a history of seizure disorders as it could potentially exacerbate seizure activity. It is also contraindicated in those with mechanical bowel obstruction or gastrointestinal hemorrhage due to the potential for worsening conditions. Hypersensitivity to metoclopramide or any of its components precludes its use.

Monitoring Requirements

Patients should be monitored for signs of tardive dyskinesia, especially with long-term use. Renal function tests are advisable before initiating therapy and periodically thereafter in patients with renal impairment. Additionally, check for the emergence of depressive symptoms as they may necessitate discontinuation of the medication.

Special Populations

In elderly patients, dosage adjustments may be required due to increased sensitivity to side effects. For pediatric patients, safety and efficacy are not well-established, necessitating caution. Pregnant women should use metoclopramide only if the potential benefit justifies the risk to the fetus. Lactating mothers should be informed about potential infant exposure through breast milk.

Administration Instructions

Metoclopramide should be taken 30 minutes before meals and at bedtime. The oral disintegrating tablet should be handled with dry hands and placed on the tongue to dissolve. For the injectable form, it is typically administered by a healthcare professional either intramuscularly or intravenously.

Storage Guidelines

Store oral tablets and oral disintegrating tablets at room temperature, away from moisture and heat. The injectable solution should be stored in a manner prescribed by healthcare regulations, typically at controlled room temperature and protected from light.

Pharmacokinetics Overview

Metoclopramide has an oral bioavailability of approximately 80%. It undergoes hepatic metabolism and is excreted primarily in the urine. The half-life of metoclopramide ranges from 5 to 6 hours, which may be prolonged in individuals with renal impairment.

Chemical Composition

Metoclopramide hydrochloride monohydrate is the main active ingredient in Reglan. The tablet form includes excipients such as microcrystalline cellulose, starch, and magnesium stearate. The injectable form contains benzyl alcohol as a preservative and sodium chloride for isotonicity.

Prescribing Considerations

Begin treatment with the lowest effective dose to minimize adverse effects. Gradual dose escalation may be performed based on patient response and tolerance. Consider periodic discontinuation or drug holidays in chronic therapy to assess the need for continued treatment and to avoid potential long-term side effects.