Medication Guide: Reglan

Generic Name

Metoclopramide.

Drug Classification

Prokinetic agent and antiemetic.

Indications

Treatment of gastroesophageal reflux disease (GERD) in patients who do not respond to standard therapy. Used for diabetic gastroparesis, nausea, and vomiting, including that induced by chemotherapy or surgery. Short-term treatment of symptoms in adults and pediatric patients when rapid control of symptoms is needed.

Mechanism of Action

Reglan works by enhancing the response of the gastrointestinal tract to acetylcholine, which increases the tone and amplitude of gastric (stomach) contractions, resulting in faster emptying of stomach and intestines. It also antagonizes dopamine receptors in the chemoreceptor trigger zone, thus preventing nausea and vomiting.

Dosage Forms and Strengths

Available as oral tablets (5 mg, 10 mg), orally disintegrating tablets (ODT), oral solution, and intravenous (IV) and intramuscular (IM) injections. Dosage and administration depend on the condition being treated and the patient’s response and tolerability.

Recommended Dose

For diabetic gastroparesis: 10 mg four times daily, 30 minutes before meals and at bedtime, recommended for 2-8 weeks. For GERD: 10-15 mg up to four times daily, 30 minutes before meals and at bedtime, recommended for 4 to 12 weeks. Adjust dosage based on patient’s response and tolerability.

Administration Routes

Can be administered orally (tablets, orally disintegrating tablets, solutions) or via parenteral routes (intravenous or intramuscular injections) based on the clinical situation and patient preference. ODT should be placed on the tongue, dissolved, and swallowed without water. IV and IM injections are used in acute settings where oral administration is not feasible.

Pharmacokinetics

Absorption: Rapidly absorbed after oral administration with peak plasma concentrations reached within 1 to 2 hours. Bioavailability is approximately 80%. Metabolism: Metabolized in the liver. Half-life: Approximately 5 to 6 hours in patients with normal renal function. Excretion: Primarily excreted in urine.

Contraindications

History of tardive dyskinesia, gastrointestinal bleeding, mechanical obstruction or perforation, pheochromocytoma, epilepsy or seizure disorders. Contraindicated in patients with hypersensitivity to metoclopramide or any other components of the formulation.

Potential Side Effects

Common side effects include drowsiness, fatigue, and restlessness. Dystonic reactions, tardive dyskinesia, parkinsonian symptoms, and neuroleptic malignant syndrome are severe but rare side effects. Other side effects can include depression, anxiety, diarrhea, and elevated blood pressure.

Drug Interactions

Interactions with anticholinergic drugs, opioids, and other central nervous system (CNS) depressants can reduce efficacy. Potential interaction with monoamine oxidase inhibitors (MAOIs) may increase the risk of hypertensive crisis. May potentiate the effects of drugs that prolong the QT interval. Concurrent use with antipsychotics could increase the risk of extrapyramidal reactions.

Special Populations

Dosage adjustments may be necessary in elderly patients, patients with impaired renal function, or those with hepatic impairment. Pregnant women should use only if the potential benefit justifies the potential risk to the fetus. Caution is advised when administering to nursing mothers due to excretion in breast milk and potential adverse effects on the infant.

Storage and Handling

Store at controlled room temperature, 15-30°C (59-86°F). Protect from light and moisture. Keep out of reach of children. Do not use past the expiration date indicated on the packaging. Vials for injection should be inspected visually for particulate matter and discoloration before administration.

Monitoring Parameters

Monitor patient for signs of improvement in symptoms and possible side effects including extrapyramidal symptoms and tardive dyskinesia. Regular hepatic and renal function tests should be performed in patients on long-term therapy to detect any potential toxicity.

Instructions for Missed Dose

If a dose is missed, take it as soon as possible unless it is almost time for the next dose. Do not double up doses to make up for missed ones. Maintain a consistent dosing schedule to optimize therapeutic effects.

Management of Overdose

In case of overdose, provide symptomatic and supportive treatment. Gastric lavage and activated charcoal administration may be beneficial. Patients should be monitored for CNS depression, severe extrapyramidal reactions, and other symptoms associated with overdose.

Non-Medication Instructions

Patients should be advised to avoid activities such as driving or operating machinery if they experience drowsiness or dizziness. Incorporation of dietary modifications and lifestyle changes may enhance the effectiveness of therapy.