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Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Brand Name
Sustol
Generic Name
Granisetron
Active Ingredient
GranisetronCategory
Serotonin-3 Receptor Antagonist [EPC]
Salt Form
Hydrochloride
Variants
1
Different strengths and dosage forms
| Strength | Form | Route | NDC |
|---|---|---|---|
| 10 mg/.4mL | INJECTION | SUBCUTANEOUS | 47426-101 |
Detailed information about Sustol
References used for this content
This page is for informational purposes only and does not replace medical advice. Before using any prescription or over-the-counter medication for Sustol, you must consult a qualified healthcare professional.
Granisetron is a potent serotonin-3 (5-HT3) receptor antagonist used to prevent nausea and vomiting caused by chemotherapy, radiation, and surgery. It works by blocking serotonin signals in the gut and brain.
Dosage for Granisetron varies significantly based on the indication and the route of administration. Healthcare providers typically follow these standard guidelines:
Granisetron is approved for pediatric use in specific contexts:
In patients with renal failure or significant kidney impairment, studies suggest that dosage adjustments are generally not required. The pharmacokinetics of Granisetron are not substantially altered by decreased kidney function, although patients should be monitored for any increase in side effects.
For patients with hepatic (liver) impairment, the clearance of Granisetron may be reduced, leading to a longer half-life. While the FDA-approved labeling does not mandate specific dose reductions for mild to moderate liver disease, healthcare providers should exercise caution in patients with severe hepatic impairment (e.g., advanced cirrhosis).
No specific dosage adjustments are required for geriatric patients (aged 65 and older). However, because older adults are more likely to have decreased renal or hepatic function and are often on multiple medications, clinicians typically start at the lower end of the dosing range.
If you miss a dose of Granisetron, take it as soon as you remember. However, if it is almost time for your next scheduled dose, skip the missed dose and return to your regular schedule. Do not 'double up' or take two doses at once. Because this medication is often used on a strict schedule before medical treatments, missing a dose may result in breakthrough nausea.
There is no specific antidote for Granisetron overdose. Signs of overdose may include extreme headache, dizziness, or a 'pounding' heartbeat. In the event of a suspected overdose, contact your local poison control center or seek emergency medical attention immediately. Treatment is generally supportive, focusing on managing symptoms and maintaining vital functions.
> Important: Follow your healthcare provider's dosing instructions exactly. Do not adjust your dose or stop taking the medication without medical guidance, especially if you are undergoing a multi-day chemotherapy regimen.
Granisetron is generally well-tolerated, but like all medications, it can cause side effects. The most frequently reported adverse reactions include:
> Warning: Stop taking Granisetron and call your doctor immediately if you experience any of these serious symptoms:
Because Granisetron is typically used for short-term prevention (during chemotherapy cycles or post-surgery), long-term data on daily use over years is limited. However, prolonged use could theoretically lead to chronic constipation or persistent alterations in liver enzyme levels. There is no evidence to suggest that Granisetron causes physical dependence or withdrawal symptoms, but it should always be used under strict medical supervision.
As of 2024, there are no FDA Black Box Warnings for Granisetron. Unlike some older antiemetics (like droperidol), Granisetron does not carry a mandatory warning for severe cardiac arrhythmias, although the risk of QT prolongation is still noted in the 'Precautions' section of the official labeling.
Report any unusual symptoms or changes in your health to your healthcare provider immediately. Keeping a 'symptom diary' can help your medical team determine if your side effects are related to Granisetron or other aspects of your treatment.
Granisetron is a potent medication that must be used with caution in patients with certain underlying health conditions. Before starting treatment, ensure your healthcare provider is aware of your full medical history, particularly any history of heart rhythm disorders or electrolyte imbalances. While Granisetron does not typically cause sedation, it can cause dizziness in some patients, which may impair the ability to perform tasks requiring alertness.
No FDA black box warnings for Granisetron. It is considered to have a favorable safety profile compared to many other medications used in the oncology setting.
Your doctor may require the following monitoring while you are on Granisetron:
While Granisetron does not usually cause significant drowsiness, the occurrence of dizziness or headaches in some patients means you should exercise caution. Do not drive or operate heavy machinery until you know how Granisetron affects you. If you feel lightheaded or faint, avoid these activities entirely.
There is no direct chemical interaction between Granisetron and alcohol. However, alcohol can irritate the stomach lining and worsen nausea, potentially counteracting the benefits of the medication. Additionally, both alcohol and Granisetron can cause dizziness; combining them may increase the risk of falls or accidents.
Granisetron is generally used 'as needed' or for short bursts during chemotherapy cycles. There is no requirement to taper the dose (gradually reduce it) when stopping. However, you should not stop taking it during a chemotherapy cycle without consulting your oncologist, as this could lead to severe 'rebound' nausea and vomiting that is difficult to control once it starts.
> Important: Discuss all your medical conditions, including any history of heart, liver, or bowel problems, with your healthcare provider before starting Granisetron.
Granisetron is not known to interfere significantly with most common laboratory tests. However, it can cause transient elevations in liver transaminases (ALT/AST) and bilirubin, which may be reflected in a comprehensive metabolic panel (CMP).
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking, including over-the-counter cold medicines and vitamins.
Granisetron must NEVER be used in the following situations:
These are conditions where the drug should be used only if the benefits clearly outweigh the risks, and under close medical supervision:
There is a known risk of cross-sensitivity among the 5-HT3 receptor antagonist class. If you have had a hypersensitivity reaction to ondansetron (Zofran), dolasetron (Anzemet), or palonosetron (Aloxi), you are at an increased risk of reacting to Granisetron. Your healthcare provider will likely choose a different class of antiemetic (such as a NK1 receptor antagonist or a corticosteroid) if a previous 'setron' allergy is documented.
> Important: Your healthcare provider will evaluate your complete medical history, including any previous drug allergies and heart conditions, before prescribing Granisetron. Always carry a list of your known allergies to share with your medical team.
Granisetron is generally classified as Pregnancy Category B (or equivalent in modern labeling), meaning that animal studies have failed to demonstrate a risk to the fetus, but there are no adequate and well-controlled studies in pregnant women.
It is not known whether Granisetron is excreted in human milk. However, because many drugs are excreted in breast milk, caution should be exercised. Animal studies have shown the presence of the drug in the milk of lactating rats. If Granisetron is necessary for the mother, a decision should be made whether to discontinue nursing for 24 hours after the dose or to use an alternative antiemetic with a better-established safety profile in breastfeeding.
Granisetron is approved for the prevention of CINV in pediatric patients as young as 2 years old (via IV administration).
Clinical trials included a significant number of patients over age 65.
In patients with renal impairment, including those on dialysis, the pharmacokinetics of Granisetron are not significantly altered. The clearance of the drug remains relatively stable. Therefore, no dosage adjustment is typically required for patients with kidney disease. However, as with all medications, clinicians monitor for unexpected side effects.
For patients with hepatic impairment, the total clearance of Granisetron is reduced by about 50% in those with severe liver disease.
> Important: Special populations require individualized medical assessment. Always inform your doctor if you are pregnant, planning to become pregnant, or have underlying organ dysfunction.
Granisetron is a potent and highly selective antagonist of 5-hydroxytryptamine (5-HT3) receptors. These receptors are ligand-gated ion channels located peripherally on vagal nerve terminals and centrally in the chemoreceptor trigger zone (CTZ) of the area postrema. During chemotherapy or radiation, mucosal damage in the small intestine causes the release of serotonin from enterochromaffin cells. This serotonin stimulates the 5-HT3 receptors on the vagus nerve, initiating the vomiting reflex. Granisetron binds to these receptors with high affinity, preventing their activation by serotonin. This blockade interrupts the signaling pathway that would otherwise lead to the sensation of nausea and the physical act of vomiting.
Granisetron's effects are dose-dependent up to a certain point, after which a plateau is reached. It does not affect lower esophageal sphincter pressure, gastrointestinal transit time (in a way that causes acute distress, though it does cause constipation), or gastric emptying. It has no significant affinity for other serotonin receptor subtypes or for alpha- or beta-adrenoceptors, dopamine D2 receptors, or histamine H1 receptors. This selectivity is why it does not cause the sedation or movement disorders associated with older antiemetic classes.
| Parameter | Value |
|---|---|
| Bioavailability | ~60% (Oral) |
| Protein Binding | ~65% |
| Half-life | 6–9 hours (Healthy); 10–12 hours (Cancer patients) |
| Tmax | 2 hours (Oral) |
| Metabolism | Hepatic (Primarily CYP3A4) |
| Excretion | Renal (12% unchanged), Fecal (metabolites) |
Granisetron is classified as a Serotonin-3 (5-HT3) Receptor Antagonist. It is part of the broader therapeutic category of antiemetics and antinauseants. Related medications in this class include Ondansetron, Dolasetron, and Palonosetron. While they share the same primary mechanism, they differ in their binding affinity and half-life.
Common questions about Sustol
Granisetron is primarily used to prevent nausea and vomiting that occurs as a result of cancer treatments, including chemotherapy and radiation therapy. It is also used in hospital settings to prevent or treat nausea and vomiting that can happen after a patient undergoes surgery and anesthesia. By blocking serotonin receptors in the gut and brain, it stops the signals that trigger the vomiting reflex. It is available in several forms, including tablets, injections, and a skin patch, to suit different treatment needs. Your doctor will determine the best form based on the intensity of the nausea expected from your specific medical procedure.
The most frequently reported side effects of Granisetron are headache and constipation. Headaches occur because the medication affects serotonin receptors that also influence blood vessels in the head; these are usually manageable with standard pain relievers. Constipation happens because serotonin is a key driver of intestinal movement, and blocking it slows down the digestive tract. Other common but less frequent side effects include a general feeling of weakness (asthenia), dizziness, and temporary changes in liver function tests. Most of these side effects are mild and resolve once the medication is stopped after the treatment cycle. If side effects become severe or persistent, you should contact your healthcare provider for guidance.
While there is no known direct chemical interaction between Granisetron and alcohol, it is generally advised to avoid alcohol while using this medication. Alcohol can irritate the stomach and worsen the very nausea that Granisetron is intended to prevent, potentially making the treatment less effective. Furthermore, both Granisetron and alcohol can cause dizziness and lightheadedness; combining them increases the risk of falls and impaired coordination. In the context of chemotherapy, alcohol may also interact poorly with other medications in your regimen or contribute to dehydration. Always consult your oncologist before consuming alcohol during any phase of cancer treatment. If you do choose to drink, do so in extreme moderation and only after the primary effects of the antiemetic have been assessed.
The safety of Granisetron during pregnancy has not been established through large-scale clinical trials in humans. It is generally reserved for cases where the benefit to the mother significantly outweighs the potential risk to the fetus, such as in severe hyperemesis gravidarum that has not responded to other treatments. Animal studies have not shown direct harm to the developing fetus, but human data is much more limited compared to other antiemetics like ondansetron. Most doctors prefer to use better-studied medications first during the first trimester. If you are pregnant or planning to become pregnant, you must discuss the risks and benefits of Granisetron with your obstetrician. It should only be used under strict medical supervision during pregnancy.
The onset of action for Granisetron depends on the method of administration. When given intravenously (IV), the medication begins working almost immediately, which is why it is often administered just minutes before chemotherapy or surgery. Oral tablets typically take about 1 hour to reach effective levels in the bloodstream, so they must be taken at least 60 minutes before the nausea-inducing event. The Sancuso transdermal patch is a slow-release form and must be applied 24 to 48 hours before chemotherapy to ensure adequate levels are reached. Once active, the effects of a single oral or IV dose usually last for about 24 hours. Your healthcare team will time your doses specifically to match the peak of your treatment's emetogenic effects.
Granisetron is not a medication that causes physical dependence, so stopping it suddenly does not cause withdrawal symptoms in the traditional sense. However, because it is used to prevent severe nausea, stopping it in the middle of a chemotherapy cycle can lead to 'breakthrough' nausea and vomiting. Once these symptoms start, they are often much harder to control than if they had been prevented in the first place. For this reason, you should follow the full schedule prescribed by your doctor, even if you feel fine. If you are experiencing side effects that make you want to stop the medication, talk to your doctor first. They may be able to adjust the dose or switch you to a different antiemetic rather than stopping treatment entirely.
If you miss a dose of Granisetron, you should take it as soon as you remember to maintain the preventive effect against nausea. However, if it is already very close to the time for your next scheduled dose, skip the missed one and continue with your regular timing. Do not take two doses at the same time to make up for a missed one, as this can increase the risk of side effects like severe headache or heart rhythm changes. Because timing is so important for preventing chemotherapy-induced vomiting, try to set a reminder or alarm for your doses. If you miss a dose and begin to feel nauseated, contact your nurse or doctor immediately for instructions on how to manage breakthrough symptoms. Consistent dosing is the key to the medication's success.
Weight gain is not a recognized or common side effect of Granisetron. Most patients take this medication for short periods—usually a few days at a time during chemotherapy cycles or following surgery—which is not long enough to cause significant changes in body weight. In fact, by preventing nausea and vomiting, Granisetron may help patients maintain their weight by allowing them to continue eating and drinking during their cancer treatment. If you notice rapid weight gain or swelling (edema) while taking this medication, it is more likely related to other treatments, such as steroids (like dexamethasone) often given alongside antiemetics, or an underlying medical condition. Always report significant weight changes to your oncology team for evaluation.
Granisetron can interact with several types of medications, so a full review of your current drugs is essential. The most serious concern is the risk of Serotonin Syndrome when Granisetron is combined with antidepressants like SSRIs or SNRIs. It can also interact with medications that affect the heart's electrical rhythm, such as certain antibiotics, antipsychotics, or heart rhythm drugs. Additionally, it should never be taken with apomorphine due to the risk of severe low blood pressure. However, it is very commonly and safely taken with other supportive care drugs like dexamethasone or NK1 antagonists (like aprepitant) to enhance its anti-nausea effects. Always provide your doctor and pharmacist with a complete list of all prescriptions, over-the-counter drugs, and herbal supplements you use.
Yes, Granisetron is available as a generic medication in several forms, including the oral tablets and the intravenous injection. Generic versions are typically much more cost-effective than the original brand-name versions (like Kytril) while providing the same clinical efficacy and safety. Some specialized forms, such as the Sancuso transdermal patch or the Sustol extended-release injection, may still be under patent protection and only available as brand-name products. If cost is a concern, ask your doctor or pharmacist if a generic version of Granisetron is appropriate for your specific treatment plan. Most insurance plans cover the generic oral and IV versions of this medication as part of standard chemotherapy supportive care.
Other drugs with the same active ingredient (Granisetron)