G Setron

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G Setron

Medically reviewed

Marina Burgos

Last updated on 22/12/2025

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 G Setron

Quick Facts

Property Description
Active ingredient Granisetron hydrochloride
Form Tablet, Solution, Injection, Transdermal Patch
Pharmacological class Selective Serotonin (5-HT3) Receptor Antagonist
General purpose Prevention and relief of nausea and vomiting
Origin Synthetic, Indazole derivative

What Type of Medicine is Granisetron (G Setron)?

G Setron is a brand name formulation containing the active pharmaceutical ingredient Granisetron (INN), which is precisely categorized as a Selective Serotonin (5-HT3) Receptor Antagonist. This classification designates it as a potent antiemetic agent, a type of drug used to control sickness. The drug is available by prescription only (Rx) and is an indazole derivative by chemical structure. This class of medication is utilized in managing severe sickness triggers. The medication's focus is on providing a specialized therapeutic option against severe sickness triggers.

Composition, Origin, and Available Forms

The active ingredient is typically formulated using the salt form, Granisetron hydrochloride, which is a highly soluble, synthetic compound. G Setron and other Granisetron products are manufactured as a single active ingredient product. The medication's versatility is a key feature, as it is available in multiple dosage forms, including the tablet and oral solution for oral administration, injectable formulations for intravenous or subcutaneous use, and a specialized transdermal patch. The availability of the transdermal patch offers a distinct advantage for continuous relief over several days. These various forms are recognized for their bioavailability and targeted systemic delivery.

The General Purpose of 5-HT3 Antagonists

The general purpose of the Granisetron class is to provide dedicated antiemetic activity to prevent or relieve episodes of nausea and vomiting arising from specific medical treatments. The function is achieved through the competitive and selective blockade of the 5-HT3 receptor sites. This targeted action is essential for managing anticipated, severe emetic events, such as those that may occur following high-risk medical procedures. This mechanism prevents the signal transmission that would otherwise lead to the activation of the brain’s vomiting center.

Regulatory References

  1. Granisetron: MedlinePlus Drug Information
  2. Granisetron hydrochloride injection, solution - DailyMed - NIH

What side effects are possible with G Setron?

The official safety profile of G Setron (Granisetron) is documented by regulatory health authorities and classifies possible adverse reactions by frequency and physiological system affected.

Frequency-Classified Adverse Reactions

Adverse events are categorized according to how often they have been observed in clinical trials, following standard regulatory conventions:

  • Very Common (ge 1/10): Headache and Constipation are the most frequently reported effects across various formulations.
  • Common (ge 1/100 to <1/10): This group includes Diarrhea, Insomnia, Asthenia (weakness), abdominal pain, and temporary elevations of hepatic transaminases (liver enzymes).
  • Uncommon (ge 1/1,000 to <1/100): Less frequent documented effects include Serotonin Syndrome, QT prolongation (a change in heart's electrical activity), and Extrapyramidal reactions.

Serious Adverse Reactions and Safety Constraints

Regulatory labeling highlights specific, clinically significant safety concerns and conditions for caution:

  • Cardiac Conduction: Cases of QT interval prolongation and arrhythmias have been reported. Caution is advised for patients with pre-existing cardiac conduction disorders, those receiving cardio-toxic chemotherapy, or those with electrolyte abnormalities.
  • Serotonergic Risks: The potential for Serotonin Syndrome is noted, particularly when G Setron is used concurrently with other medications that affect serotonin levels.
  • Hypersensitivity: Severe hypersensitivity reactions, including anaphylaxis, have been documented. The medication is formally contraindicated in individuals with a known hypersensitivity to granisetron.
  • Gastrointestinal Masking: The medicine may mask the signs of a progressive ileus or gastric distension, which is a safety consideration for patients with risk factors for gastrointestinal obstruction or recent abdominal surgery.

Overdose and Emergency Response

The official regulatory documentation for G Setron overdosage establishes that a specific antidote is not known, and management is limited to supportive and symptomatic care. In documented instances of overexposure, including high doses of the injectable formulation, patients may experience only a slight headache or remain entirely asymptomatic.

Despite the typically mild presentation of simple overdosage, official labeling notes the potential for serious risks. The development of Serotonin Syndrome is a documented concern associated with 5-HT3 receptor antagonists, which may present with severe symptoms like mental status changes (e.g., agitation, delirium), autonomic instability (e.g., rapid heartbeat, hyperthermia), and specific neuromuscular findings (e.g., rigidity). The labeling also notes the possibility of QT prolongation and other ECG abnormalities.

Immediate medical help is required upon the onset of symptoms suggestive of Serotonin Syndrome, and the drug must be immediately discontinued. A specific regulatory caution exists for the injectable formulation due to the benzyl alcohol excipient, which can cause "Gasping Syndrome" in neonates, highlighting a critical population-specific overdose risk.

Therapeutic Uses of G Setron

What G Setron Treats: Main Uses and Benefits

Granisetron is an antiemetic medication relevant for easing symptoms associated with high-risk medical procedures. The therapeutic focus is aligned with established clinical indications.

This medication is commonly used to help manage nausea and vomiting associated with emetogenic cancer therapy (chemotherapy and radiation) and to prevent and treat sickness following surgical procedures (postoperative nausea and vomiting, or PONV) in adults. It is applied across domains where additional symptomatic support is needed to address symptom clusters that create noticeable physiological strain, covering both the immediate (acute) and delayed phases of sickness.

Therapeutic Applications

In clinical settings that involve acute symptom patterns, this medication is relevant for easing symptoms that create noticeable physiological strain. This provides support that helps ease the overall symptom burden and assists with maintaining functional stability. This application contributes to improved comfort during the critical recovery period.


Quick Fact: Symptomatic Relief Area of Use Symptom Focus Benefit
Oncology Support Acute and delayed emesis Supports general well-being during symptomatic phases
Perioperative Care Post-surgery sickness Assists with maintaining functional stability

Regulatory References

  1. NIH DailyMed official labeling

Eligibility and Restrictions for Use

Eligibility Map: Who can and cannot use G Setron — Official Regulatory Information

This section details official eligibility and restriction criteria for G Setron, strictly based on government regulatory labeling (e.g., FDA, EMA documents).


Contraindicated Populations (Must Not Use)

  • Patients with known hypersensitivity (e.g., severe allergic reaction) to G Setron or any of its components.
  • Patients receiving concomitant apomorphine (due to the risk of profound hypotension and loss of consciousness).

Restricted/Special Consideration Use

Classification Population/Condition Restriction/Action
Avoid Use Congenital Long QT Syndrome Due to risk of dose-dependent QT prolongation and Torsade de Pointes.
Dose Restriction Severe Hepatic Impairment Maximum recommended daily dose (e.g., 8 mg IV) may be required.
Warning Children under 4 years old Oral forms are generally not approved for the prevention of chemotherapy-induced nausea/vomiting in this age group, though other formulations may be approved for children as young as one month for other indications.

General Eligibility

Use is allowed for adults and pediatric patients aged one month and older for approved indications and formulations, provided no contraindications exist. The use of G Setron in pregnancy was formerly assigned a Category B status (animal studies show no risk, human data inadequate). Renal impairment does not typically require a dose adjustment.

What should I know about interactions with other medicines?

Interaction Map: Interactions with other medicines and products — official regulatory information for Granisetron (G Setron)


Interaction scope

Category Official Regulatory Documentation
Medicinal product categories with documented interactions: Serotonergic medicinal products; QT-prolonging drugs; Hepatic enzyme inducers/inhibitors; Other 5-HT3 antagonists.
Specific interacting medicines (if explicitly listed): Apomorphine (Contraindicated); Phenobarbital (Enzyme Inducer); Ketoconazole (CYP3A4 Inhibitor, in vitro); Oral Paracetamol.
Mechanistic basis of interactions (only if stated in label): Pharmacodynamic effects (additive serotonergic/cardiotoxic load); Pharmacokinetic effects (modification of clearance via hepatic enzyme induction/inhibition).
Timing-based interaction rules (if applicable): For the Granisetron Extended-Release (ER) Injection only: Other 5-HT3 antagonists must not be used concurrently (within 7 days).
Population-specific interaction notes (if applicable): Patients with renal or hepatic impairment require a degree of caution based on Granisetron pharmacokinetics.

Interaction classifications (high-level)

Category Official Regulatory Statement / Classification
Interaction severity classification (as defined in official documents): Contraindicated (with Apomorphine); Use with caution (with Serotonergic/QT-prolonging agents).
Regulatory basis (EMA / FDA / etc.): Information is based on official prescribing documents.

Resulting interaction structure

Official interaction statements:

  • Coadministration with Apomorphine is formally contraindicated due to the reported risk of profound hypotension and loss of consciousness.
  • Co-use with other Serotonergic medicinal products (e.g., SSRIs, MAOIs) has been associated with the documented risk of serotonin syndrome.
  • The coadministration of QT-prolonging drugs may result in clinical consequences via additive pharmacodynamic effects.
  • Phenobarbital coadministration leads to a 25% increase in total plasma clearance of intravenous Granisetron.
  • Concomitant use with oral paracetamol has been reported to result in a block in the analgesic effect.

Connection to the overall interaction profile (2–4 sentences):

The regulatory documents define the interaction structure around one severe contraindicated combination and critical pharmacodynamic risks associated with additive effects on serotonin and cardiac conduction. The profile also includes label-documented pharmacokinetic modifications (e.g., increased clearance with Phenobarbital) and a formulation-specific timing restriction for the extended-release product. This communicates the official requirements and high-level interaction classifications mandated by government agencies.

Mechanism of Action

G Setron's action is defined by a precise molecular mechanism that interrupts the nerve signals within the emetic reflex arc. The mechanism exerts an influence on this reflex arc by targeting a single neurotransmitter receptor.

Selective Blockade of the 5-HT3 Receptor

G Setron acts as a selective antagonist of the Serotonin 5-HT3 Receptor (5-HT3R), a specific type of ligand-gated ion channel. By binding competitively to this receptor, the drug prevents the natural chemical messenger, serotonin, from causing activation. This mechanism contributes to the interruption of the signal cascade that originates in response to certain chemical triggers.

Dual-Site Inhibition of the Emetic Reflex

The drug's mechanism involves blocking 5-HT3R sites at two critical locations: in the periphery, on the vagal afferent nerve terminals of the gut, and centrally, in the brain's Chemoreceptor Trigger Zone (CTZ). This dual-site blockade interferes with the generation of the nerve impulse at its source and also modulates its processing gateway in the brainstem.

Inhibition of Neuronal Signal Transmission

The 5-HT3 receptor, when blocked by G Setron, remains closed, which stops the influx of positive ions ( Na^+ and Ca^2+) into the nerve cell. This molecular interference prevents the depolarization of the neuron and the subsequent propagation of the emetic impulse. The physiological consequence is the inhibition of neuronal signal propagation within the emetic reflex arc.

Dosage and Administration Information

Official Administration Protocol

Granisetron (G Setron) is used as a time-critical, prophylactic treatment, with specific administration protocols defined by its four dosage forms: oral (tablet/solution), intravenous (IV) injection, subcutaneous (SC) extended-release injection, and transdermal patch. The choice of route and form dictates the setting of use, from self-administration to supervised clinical settings.


Dosing and Timing Principles

Administration occurs before the anticipated emetic event to align with its intended function. The standard IV dose for preventing sickness associated with chemotherapy is a single 10 mcg/kg dose, given within 30 minutes prior to the start of treatment. Oral regimens involve either 1 mg twice daily or 2 mg once daily, typically taken 1 hour before therapy begins. The transdermal patch is applied to the upper outer arm 24 to 48 hours before the start of chemotherapy.


Procedural and Duration Constraints

The duration of use is defined by the dosage form. Oral therapy for delayed sickness is generally restricted to seven consecutive days. The SC extended-release injection provides a single 10 mg dose per treatment cycle and is restricted to a maximum frequency of once every seven days. Proper administration of the IV solution requires adherence to specific dilution and infusion rates, and the SC extended-release product requires warming prior to the slow, sustained injection.


Population-Specific Use

A frequency adjustment applies to the SC extended-release injection in patients with moderate renal impairment (creatinine clearance 30 to 59 mL/min). In this population, the injection is administered no more often than once every 14 days. No dose adjustment is specified for the IV, oral, or transdermal forms in patients with mild hepatic or renal impairment.

Recent Clinical Evidence

G Setron: Recent Clinical Evidence

Research has investigated G Setron (a 5-HT3 receptor antagonist) for its use in preventing and managing nausea and vomiting associated with chemotherapy (CINV) and other clinical settings. Studies suggest that G Setron's action involves blocking the effects of serotonin released in the gastrointestinal tract and the brainstem, which is a key process in the initiation of vomiting.


Efficacy and Outcome Trials

Major clinical trials, primarily focusing on CINV prophylaxis, have evaluated G Setron in various treatment regimens. A key Phase III study evaluating G Setron in combination with other antiemetics for highly emetogenic chemotherapy (HEC) reported on the complete response (CR) rate (no vomiting/retching and no rescue medication). CR rates were reported across the acute (0–24 hours) and delayed (>24–120 hours) phases following chemotherapy administration.

Comparative research has also been conducted, including a randomized trial that assessed G Setron against another 5-HT3 receptor antagonist in patients receiving HEC. This study did not find a difference between the two treatments regarding the primary endpoint (overall CR rate) but reported some variance in secondary endpoints and during the delayed phase.


Safety and Tolerability Profile

Across multiple studies, the safety profile of G Setron has been generally reported, with headache and constipation being the most frequently reported adverse events. As with other drugs in this class, research indicates that G Setron may be associated with changes in the electrocardiogram (ECG) intervals, such as QTc prolongation. Therefore, special caution and monitoring are generally considered for patients with existing cardiac conditions or those taking other medications known to affect the heart's rhythm.

Frequently Asked Questions (FAQ)

Common questions about G Setron (FAQ)

Q: Is G Setron used for any condition other than what is commonly known?

According to official regulatory documents, G Setron (granisetron) is formally approved for the prevention and treatment of nausea and vomiting associated with chemotherapy (CINV) and radiotherapy (RINV).

It is also approved for the prevention and treatment of post-operative nausea and vomiting (PONV).


Q: How quickly does G Setron usually start working after taking it?

Pharmacokinetic data from the official prescribing information helps characterize the drug's absorption rate.

For the oral tablet or solution, the maximum concentration of G Setron in the bloodstream is often observed within approximately two hours after the dose is taken.


Q: What is the typical timeframe for G Setron to reach its maximum effect?

The time it takes for G Setron to reach its maximum effect in the bloodstream (known as Tmax) is approximately two hours for the oral formulation.

This measure is an indicator of the time required for the drug to be absorbed into the body’s system.


Q: How long can the effects of G Setron be expected to last?

The drug's elimination half-life (t1/2) is the measure used to characterize how long it takes for the concentration to decrease in the body.

Based on pharmacokinetic studies, the half-life for granisetron has been reported to range between approximately 3 to 14 hours following administration.


Q: Is G Setron available as a generic medicine, or only under a brand name?

The active ingredient, granisetron, is available in generic form for many formulations, including oral tablets and injectable solutions.

However, some specialized formulations, such as the extended-release injection or the transdermal patch, may still be available only under their specific brand names.


Q: Are there different brand names under which G Setron is sold?

Yes, the active ingredient granisetron is sold under several brand names worldwide.

Examples of specific brand names in the US include Kytril, Sancuso (the transdermal patch), and Sustol (the extended-release injection).


Q: What is the difference between G Setron and similar sounding drugs like Ondansetron?

G Setron (granisetron) and medications like Ondansetron are both classified as selective 5-HT3 receptor antagonists.

Official documents have reported cases of cross-sensitivity between granisetron and other drugs in this same antiemetic class.


Q: Does G Setron interact with any common herbal medicines or natural remedies?

Official documents caution that G Setron may interact with other medicines that increase the levels of serotonin. This coadministration has been associated with a documented risk of serotonin syndrome.

Official guidance emphasizes the importance of informing the healthcare provider of all products being used, as certain herbal products and natural remedies may also possess serotonergic properties.


Q: What are the official warnings about taking G Setron while operating machinery?

Official warnings state that side effects such as drowsiness (somnolence) and dizziness have been reported with this medication.

As a result, patients are generally cautioned against driving or operating complex machinery due to these reported effects.


Q: Can G Setron cause an allergic reaction, and what are the signs?

The official safety profile indicates that severe hypersensitivity reactions, including anaphylaxis, have been reported in rare cases.

Reported signs of a severe reaction have included difficulty breathing, wheezing, swelling of the face, lips, tongue, or throat, or low blood pressure.


Q: Does G Setron have any known potential for dependency or misuse?

Regulatory bodies, such as the U.S. Drug Enforcement Administration (DEA), have not classified granisetron as a controlled substance.

This indicates that the drug does not have a formal regulatory designation related to abuse or dependency potential.


Q: What kind of tests or check-ups are generally required when starting G Setron?

Due to the reported risk of QTc prolongation, which can affect the heart’s electrical activity, certain assessments may be necessary.

Official warnings advise caution for patients with existing cardiac conduction issues or those with electrolyte abnormalities; therefore, assessment of these factors may be considered by a healthcare professional before or during treatment.


Q: Does G Setron affect the results of any common blood tests?

Official documentation reports that temporary elevations of hepatic transaminases, which are a type of liver enzyme, have occurred in some patients.

These enzymes are typically measured through common blood tests.


Q: Are there any specific side effects of G Setron that are more common in the elderly?

Official guidance indicates that no dose adjustment is typically specified for the IV or oral forms in the elderly population.

However, a frequency adjustment is required for the SC extended-release injection in patients with moderate renal impairment, a condition more common in the elderly; therefore, a healthcare professional may exercise caution.


Q: Does G Setron contain common allergens like lactose or gluten?

Official excipient lists show that certain G Setron tablet formulations contain lactose.

If a patient requires strict avoidance of specific excipients, it is necessary to check the full ingredient list of the specific product against its official regulatory label.


Q: Is it safe to drink alcohol while using G Setron?

Official consumer information notes the need for caution regarding the co-use of alcohol with G Setron.

This is because alcohol consumption may potentially worsen certain side effects, such as dizziness or drowsiness, that are known to be caused by granisetron.


Q: Is it normal to feel a metallic taste after taking G Setron?

Taste disorder is officially listed as a common side effect associated with the use of granisetron.

This taste disorder may include the sensation of a metallic taste.


Q: What happens if a scheduled intake of G Setron is missed? (Informational)

Because G Setron is usually given as a prophylactic (preventative) treatment, its effectiveness may be compromised if a scheduled dose is missed before a procedure.

Official consumer information advises that if a scheduled preventative dose is missed, immediate communication with the prescribing doctor is necessary, as the treatment may need to be rescheduled.


Q: What should be done if someone accidentally takes too much G Setron? (Non-advice)

Official guidance states that in the event of a suspected overdose, emergency medical attention should be sought immediately, and the local poison control center should be contacted.

This advice is based on potential clinical consequences documented in regulatory information.


Q: Where can I find the official patient information leaflet (PIL) for G Setron?

The official patient information leaflet (PIL) or Medication Guide is provided with the prescription and is also available online.

These documents can be accessed publicly through governmental drug databases, such as the FDA DailyMed website or the public portals of the EMA or MHRA.


Q: Has G Setron been approved for use in countries outside of North America?

Yes, the active ingredient granisetron is an approved medication and is available under various names globally.

Its approval is recognized in many countries, including those governed by the European Medicines Agency (EMA) and the United Kingdom's MHRA.


Q: How long has the drug G Setron been available on the market?

The active ingredient, granisetron, has been available on the market for several decades.

It was originally approved by the US Food and Drug Administration (FDA) in 1994, and earlier in the United Kingdom in 1991.

How should G Setron be stored and disposed of?

How to Store and Dispose of Granisetron (G Setron)

Storage requirements for granisetron depend strictly on the dosage form, as outlined in official regulatory labeling.

Storage Requirements

Dosage Form Required Storage Condition
Tablets / Oral Solution Controlled room temperature (20°C to 25°C); protect from light.
Injection Concentrate Controlled room temperature; do not freeze; protect from light.
Extended-Release Injection Refrigerate (2°C to 8°C); do not freeze. Must be allowed to warm before use.

All forms must be stored out of the sight and reach of children. The oral solution must be kept in its original container.

Disposal

Used transdermal systems (patches) must be folded in half, adhesive sides together, and disposed of in the household trash to prevent access. For other unused or expired formulations, follow official governmental guidance, which typically advises against flushing them down the toilet.

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

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