Gastrine

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Gastrine

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Medically reviewed

Marina Burgos

Last updated on 10/01/2026

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Gastrine

What is Gastrine and What is its Purpose?

Gastrine is a specialized combination drug classified as an Antacid and Antiflatulent Combination, serving the general therapeutic purpose of providing relief from gastric distress and associated symptoms. This Over-the-counter (OTC) product is designed for oral administration to manage discomforts related to hyperacidity and accumulated intestinal gas. Its dual-action formulation simultaneously addresses the effects of stomach acid, such as heartburn and reflux symptoms, and the physical discomfort caused by flatulence and bloating in adults and adolescents.

The medicine helps ease discomfort by buffering the existing acid in the stomach to neutralize its effects.


Composition and Classification: Magaldrate and Simethicone

The core identity of Gastrine is defined by its two primary active ingredients: Magaldrate and Simethicone. This pairing is used to provide relief in scenarios characterized by excessive stomach acid accompanied by gas, differentiating it from single-ingredient acid reducers. Magaldrate is a synthetic compound known as an aluminate, which functions as the primary agent for chemical acid neutralization. Simethicone, the secondary active component, belongs to the class of siloxanes and acts physically through a defoaming action to break down gas bubbles.

This blend, available in both an oral suspension and chewable tablets, makes Gastrine a non-systemic GI protector. Magaldrate-Simethicone formulations are commonly used in treating shared symptoms of various gastrointestinal disorders.

Regulatory References

  1. MedlinePlus Antacids
  2. FDA Simethicone Designation

What side effects are possible with Gastrine?

Possible Side Effects and Safety Information

This section outlines the possible adverse reactions and safety-related information for Gastrine as documented in official government regulatory sources, such as the FDA, EMA, and Health Canada. This information is classified by frequency and body system.

Documented Adverse Reactions

Adverse reactions observed in clinical studies and post-marketing surveillance are categorized by the body system affected (System-Organ Class) and the estimated frequency (Very Common, Common, Uncommon, Rare, etc.).

  • Gastrointestinal Disorders: This class includes reactions such as diarrhea, abdominal pain, and nausea, often falling into the Common frequency category.
  • Metabolism and Nutrition Disorders: Reactions like elevated serum gastrin levels are documented and monitored.
  • Nervous System Disorders: Headaches and dizziness have been reported.
  • Hepatobiliary Disorders: These can include elevations in liver enzymes.
  • Blood and Lymphatic System Disorders: Rare instances of Agranulocytosis (a serious reduction in white blood cells) have been documented.

Serious and Clinically Significant Safety Information

Specific serious adverse reactions highlighted in regulatory documents include Severe Hepatic Enzyme Elevations and Agranulocytosis. Long-term use is a noted safety consideration, as chronic drug-induced hypergastrinemia has been associated with the development of gastric carcinoid tumors in non-clinical studies. This association requires ongoing assessment and monitoring.

Restrictions and Population Considerations

Gastrine is formally contraindicated in patients with severe renal impairment. Caution and monitoring are also specified for use in patients with pre-existing hepatic impairment. The use of Gastrine is not recommended in pediatric populations due to insufficient safety and efficacy data.

Overdose and Emergency Response

A suspected overdose of Gastrine (Magaldrate and Simethicone) requires immediate medical attention as mandated by official regulatory guidance. The official labeling specifies a range of documented manifestations associated with excessive intake, primarily affecting the gastrointestinal system. These presentations may include non-severe symptoms such as nausea, vomiting, stomach cramps, constipation, diarrhea or loose stool, and a chalky taste in the mouth.

Beyond gastrointestinal symptoms, the official profile highlights the potential for serious metabolic risks due to the Magaldrate component. Specifically, there is a risk of both Hypermagnesemia and Aluminum accumulation following significant or chronic excessive exposure. Regulatory documents emphasize that individuals with Impaired Renal Function (Kidney Disease) face a highly increased risk of serious toxicity from magnesium accumulation.

In the event of an overdose, regulators require the user to seek emergency medical care and contact a Poison Control Center. Management of a Gastrine overdose is described as primarily symptomatic and supportive, centered on discontinuing the medication. The official product information notes that no specific antidote is known for the Simethicone component, reinforcing the reliance on supportive clinical management.

Therapeutic Uses of Gastrine

Main Uses of Gastrine

Gastrine is a therapeutic agent primarily used to manage conditions related to the overproduction of gastric acid. By targeting the underlying mechanisms of acid secretion, it helps in the treatment and long-term management of several gastrointestinal disorders.

Treatment of Gastric and Duodenal Ulcers

The primary application of Gastrine is the treatment of peptic ulcers, which include both gastric ulcers (located in the stomach) and duodenal ulcers (located in the upper part of the small intestine). The medication works by reducing the acidity of gastric juices, allowing the mucosal lining of the digestive tract to heal and preventing the recurrence of further ulcerations.

Management of Gastroesophageal Reflux Disease (GERD)

Gastrine is frequently prescribed for individuals suffering from gastroesophageal reflux disease (GERD). In this condition, stomach acid flows back into the esophagus, causing irritation and inflammation. By lowering acid levels, Gastrine helps alleviate symptoms such as heartburn and acid regurgitation, and it aids in the healing of erosive esophagitis.

Hypersecretory Conditions

This medication is also utilized in the management of pathological hypersecretory conditions, such as Zollinger-Ellison syndrome. In these rare cases, the stomach produces excessive amounts of acid, leading to severe peptic ulceration and other complications. Gastrine assists in controlling these high levels of acid production over extended periods.


Benefits of Treatment

Mucosal Protection and Healing

By effectively reducing the chemical aggression of gastric acid, Gastrine facilitates the natural repair processes of the gastrointestinal mucosa. This is essential for the resolution of internal lesions and the prevention of complications such as gastrointestinal bleeding or perforation.

Symptomatic Relief

The reduction of gastric acidity provides significant relief from the discomfort associated with acid-related disorders. Patients typically experience a decrease in burning sensations, bloating, and upper abdominal pain, which contributes to an overall improvement in digestive comfort.

Prevention of Recurrence

Beyond acute treatment, Gastrine plays a role in maintenance therapy. By stabilizing the environment of the digestive system, it helps prevent the relapse of ulcers and maintains the integrity of the esophageal lining in chronic reflux sufferers.

Regulatory References

  1. DailyMed Labeling for Antacid/Antiflatulent Granules

Eligibility and Restrictions for Use

Gastrine is a synthetic drug intended to mimic the action of the natural hormone gastrin. It is not typically used for routine treatment but primarily as a diagnostic aid for certain gastrointestinal conditions.

Who Can Use Gastrine?

It is mainly administered to patients to evaluate:

  • Gastric Acid Secretory Function: To assess the stomach's ability to produce hydrochloric acid, often in cases of suspected pernicious anemia, atrophic gastritis, or gastric carcinoma.
  • Gastric Hypersecretion: To aid in the diagnosis of conditions involving excessive stomach acid production, such as Zollinger-Ellison Syndrome (gastrinoma).

Who Cannot Use Gastrine?

While the drug is generally reserved for diagnostic procedures, caution is required, and use is generally avoided or strictly limited in the following populations due to potential risks, especially with high or repeated doses:

Patient Group Reason for Caution/Avoidance
Allergy Known hypersensitivity to the drug or similar peptides.
Active Cardiovascular Disease Potential for adverse cardiac events, as the natural hormone can affect the cardiovascular system.
Pregnant or Breastfeeding Individuals Lack of sufficient safety data in these populations.

The trophic (cell-growth promoting) properties of gastrin may also raise concern in patients with a history of certain gastrointestinal malignancies, given its role in cell proliferation.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Gastrine's interaction profile is defined by the pharmacokinetic action of the Magaldrate antacid component, which alters the absorption of co-administered oral medicines. The antacid's ability to change gastrointestinal pH leads to a documented reduction in the systemic exposure and plasma concentration of various drugs, including quinolone antibiotics (e.g., Ciprofloxacin), Digoxin, Isoniazid, and Chlorpromazine. Conversely, this mechanism is officially documented to increase the systemic exposure of Levodopa, which carries a documented risk of toxicity.

To manage these absorption-altering effects, official labeling mandates a timing separation: other oral medicinal products must be administered at least two hours before or two hours after taking Gastrine. Regulatory documents designate co-administration with Tetracycline antibiotics and oral Iron salts as contraindicated combinations in certain regions due to severely reduced absorption of those substances.

Furthermore, a specific population-dependent interaction is noted: patients with renal failure or renal dysfunction face a documented increased risk of Aluminum accumulation (intoxication) and Hypermagnesemia due to impaired renal clearance of the absorbed antacid components. No specific interactions with food, alcohol, or herbal products are documented in the official labeling.

Mechanism of Action

How Gastrine Works

The mechanism of Gastrine is entirely non-systemic, relying on two distinct, local actions to modulate the physiological state within the gastrointestinal lumen.

Chemical Neutralization and Pepsin Control

Magaldrate provides an immediate chemical buffering action by consuming free hydrogen ions ( H^+), resulting in a rapid elevation of gastric pH. This process is essential as the elevated pH causes the inactivation of pepsin, a proteolytic enzyme, thereby reducing the corrosive potential of the fluid and limiting proteolytic activity.

Physical Barrier Formation and Cytoprotection ️

Magaldrate further engages a protective mechanism through physical adherence to the stomach and esophageal surfaces. It forms a viscous gel layer that acts as a physical shield, contributing to the reinforcement of the mucosal barrier against the remaining corrosive contents, thus modulating the chemical environment of the lining.

Alteration of Intraluminal Gas Dynamics

The antiflatulent component, Simethicone, initiates a purely physical alteration by reducing the surface tension of the liquid surrounding gas bubbles. This action causes smaller, trapped bubbles to coalesce into larger, mobile gas masses, contributing to the movement and elimination of the resultant gas pockets.

Dosage and Administration Information

How to Use Gastrine: Official Administration Guidelines

Gastrine is an Antacid and Antiflatulent Combination with a specific administration routine, focusing strictly on procedural use. This information describes the standardized approach to its intake without referencing mechanisms or therapeutic benefits.


Administration Scope

Procedural Element Official Labeled Instruction
Route of Administration Oral
Dosing Schedule Single doses range from 10 mL to 20 mL of the oral suspension or 1 to 4 chewable tablets for adults and adolescents
Maximum Daily Dose Intake must not exceed 80 mL (or tablet equivalent) in a 24-hour period
Frequency and Timing Up to four times a day (QID), with doses administered after meals and at bedtime
Duration Constraint Continuous use of the maximum daily dose should not exceed two weeks

Procedural and Population Rules

Gastrine is available as an oral suspension and in chewable tablets, requiring distinct handling steps. The suspension must be shaken well prior to measurement, and doses should be accurately measured using a calibrated device. Chewable tablets must be thoroughly chewed before swallowing.

Use of the standard adult dosing regimen is designated for adults and children 12 years of age and older. Dosing for children under 12 years requires individualized professional guidance. This standardized protocol ensures the medication is used strictly for short-term, acute periods as defined by the official use-context constraints.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Gastrine

Research Evidence for Combined Acid and Gas Relief

Gastrine, a combination agent, was studied in research exploring how symptoms change over time in individuals reporting concurrent stomach acid excess and trapped gas. The scientific support for this combination was derived from several sources, including controlled trials focused on the individual antacid and antiflatulent components, as well as observational studies applied in research contexts involving fluctuating or unstable symptoms. The evidence structure also involves Randomized Controlled Trials (RCTs) focusing on research examining outcomes related to the individual components, which are relevant in trials assessing short-term or episodic symptom patterns.


How Outcomes Were Measured in Clinical Research

Research protocols primarily monitored outcomes related to physical discomfort and outcomes describing episodic or acute changes in the digestive tract. Studies focusing on gastric hyperacidity measured the intensity of symptoms like heartburn and acid regurgitation using validated scales. For the gaseous discomfort component, research examined self-reported feelings of bloating and flatulence. The study design meant that researchers observed responses over defined time intervals, tracking how symptoms evolved in the observed populations.


Long-Term Evidence and Follow-Up Duration

The majority of studies conducted on this type of symptomatic relief agent utilize limited follow-up durations. Clinical investigations was observed in study populations over short periods, typically ranging from a few weeks to one month (e.g., 15 to 30 days). Consequently, there is limited information for long-term outcomes regarding the sustained symptomatic patterns. Long-term effects are not fully established, and the extended maintenance of observed patterns has not been extensively characterized.


Evidence in Specific Patient Groups and Research Gaps

The core research was evaluated in adult patients diagnosed with conditions characterized by periods of heightened symptoms. However, data for certain groups remain insufficient. For instance, evidence for use in pediatric populations (children and adolescents) and patients with specific comorbid conditions is limited. Furthermore, evidence for the specific formulation was derived from findings involving analogous compounds or individual components, and comparative evidence is lacking in some research scenarios.

Key Studies & References

  1. Antacids: MedlinePlus Encyclopedia
  2. Labeling for Antacid/Antiflatulent Granules (DailyMed/NIH)

Frequently Asked Questions (FAQ)

Common questions about Gastrine (FAQ)


Q: Is Gastrine safe for long-term use?

A: Official product information specifies that continuous use of the maximum daily dose should not exceed two weeks. Because this product is intended for short-term, acute relief, official labeling advises that a healthcare provider be consulted if symptoms continue or get worse.


Q: How quickly should I expect Gastrine to start working?

A: Gastrine contains an antacid component, which is formulated for the immediate chemical buffering of stomach acid. Antacid relief is typically described as rapid due to its local action in the stomach.


Q: Is it okay to drive or operate machinery while taking Gastrine?

A: Official labeling documents list side effects such as dizziness or headaches as reported adverse reactions. Understanding one's personal response to the medication is advised before engaging in activities that require complete mental alertness, such as driving or operating heavy machinery.


Q: Do I need to take Gastrine with food?

A: The official administration instructions specify taking doses after meals and at bedtime. This specific timing is outlined in the official instructions for administration.


Q: What happens if I miss a dose of Gastrine?

A: This detailed guidance on managing missed doses is typically located in the product's official 'Directions for Use' section. This information should be followed strictly as written on the product label.


Q: Can Gastrine be taken with thyroid medication?

A: Gastrine, like many antacids, can alter the absorption of various oral medications. The official labeling requires a timing separation: other oral products must be taken at least two hours before or two hours after Gastrine. This helps manage the potential for reduced absorption of co-administered medications.


Q: Are there studies on Gastrine's use in pregnant or breastfeeding populations?

A: Official information indicates that no controlled data in human pregnancy are available to fully assess risk. Likewise, there are no data on the excretion of the active ingredients into human milk. Due to the lack of sufficient data, assessment by a healthcare professional is necessary before use during pregnancy or breastfeeding.


Q: Are there different strengths or formulations of Gastrine?

A: Yes, official labeling confirms that Gastrine is available in the form of an oral suspension and chewable tablets. The active ingredient strengths will differ between these two formulations.


Q: Does the time of day I take Gastrine matter?

A: Yes, the official dosing schedule is specific. Doses are recommended up to four times a day (QID), taken after meals and at bedtime for targeted relief.


Q: Why do some people experience mild headaches when they first use Gastrine?

A: Headaches are listed in the official safety information as a reported adverse reaction (a Nervous System Disorder). Regulatory documents classify this as a known possible effect, but they do not provide a detailed mechanism or reason for the headache.


Q: Why is Gastrine sometimes called a 'gastroprotectant'?

A: The Magaldrate component creates a physical barrier by adhering to the GI lining. This action helps to reinforce the mucosal barrier against corrosive contents, which is why the drug is sometimes referred to as having gastroprotective properties.


Q: Does Gastrine help with simple heartburn or only more severe conditions?

A: The product is indicated for the relief of gastric distress related to hyperacidity and gas. This includes symptoms that people experience regularly, such as simple heartburn and acid reflux symptoms.


Q: Do caffeine products interfere with the effectiveness of Gastrine?

A: Regulatory documents explicitly state that no specific interactions with food, alcohol, or herbal products are documented in the official labeling. Caffeine is not listed as a specific interacting substance.


Q: Is it necessary to avoid specific foods while on a course of Gastrine?

A: Official labeling explicitly states that no specific interactions with food, alcohol, or herbal products are documented. However, the standard dosing is timed to be taken after meals.


Q: Can certain herbal teas interact with Gastrine?

A: Regulatory documents explicitly state that no specific interactions with herbal products are documented in the official labeling.


Q: Can taking Gastrine lead to nutrient absorption issues?

A: The antacid component is officially documented to alter the absorption of co-administered oral medicines, potentially reducing their effect. No broad warning regarding general nutrient absorption is detailed in official documents.


Q: What are the key ingredients in Gastrine besides the active substance?

A: The active ingredients are Magaldrate and Simethicone. The specific inactive ingredients (excipients), which include stabilizers, flavors, and preservatives, are listed in the product's full official labeling details.


Q: Do I need a follow-up appointment after starting Gastrine?

A: Official labeling is for short-term use, and official labeling states that a healthcare provider should be consulted if symptoms persist or worsen.


Q: How does the body eliminate or break down Gastrine?

A: The official product information describes the mechanism as non-systemic, meaning the active ingredients are minimally absorbed into the bloodstream. The majority of the dose is expected to be eliminated through the gastrointestinal tract (feces).


Q: Is a metallic taste in the mouth sometimes linked to taking Gastrine?

A: Regulatory sources associated with the Magaldrate component have reported a chalky taste as a possible side effect. A metallic taste is not specifically listed in the official safety information.


Q: Is there a generic version of Gastrine available?

A: Since the active ingredients, Magaldrate and Simethicone, are established components often part of an OTC Monograph, the combination is available from various companies as generic or store-brand products due to the established nature of the active ingredients.

How should Gastrine be stored and disposed of?

How to Store and Dispose of Gastrine?

Storing Gastrine properly is essential to maintain its stability and effectiveness, as defined by official regulatory documentation.

Storage and Handling Requirements Official Classification
Temperature Store below 25 C (77 F). Do not freeze.
Protection Protect from light and moisture. Keep the container tightly closed and in the original outer carton.
Handling Do not shake the product. Keep out of the sight and reach of children.
In-use Stability Discard any unused medicine 28 days after the container is first punctured, even if refrigerated.

Disposal Instructions:

Official guidelines mandate that unused or expired Gastrine must be disposed of according to local pharmaceutical waste requirements. To prevent environmental contamination, do not flush this medicine down the toilet or pour it into a drain.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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