Granisetron 1mg Tablets

Granisetron is a selective 5-hydroxytryptamine3 (5-HT3) receptor antagonist. Chemotherapeutic agents and radiation therapy can cause release of serotonin from enterochromaffin cells of the small intestine, which then stimulates 5-HT3 receptors located on vagal afferent neurons, initiating the vomiting reflex. Granisetron blocks this stimulation, thereby preventing nausea and vomiting.

Urgent Side Effects: Seek Medical Help Right Away

Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor immediately or seek emergency medical attention:

Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of high or low blood pressure, including:
+ Severe headache
+ Dizziness
+ Passing out
+ Changes in eyesight
Chest pain or pressure
Fast or abnormal heartbeat
Shortness of breath
Stomach pain
Swelling of the abdomen
Fever, chills, or sore throat
Unexplained bruising or bleeding
Feeling extremely tired or weak

Additionally, a severe and potentially life-threatening condition called serotonin syndrome may occur, especially if you are taking certain other medications. Seek medical help immediately if you experience:

Agitation
Changes in balance
Confusion
Hallucinations
Fever
Fast or abnormal heartbeat
Flushing
Muscle twitching or stiffness
Seizures
Shivering or shaking
Excessive sweating
Severe diarrhea
Upset stomach
Vomiting
Severe headache

Other Possible Side Effects

Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:

Headache
Dizziness
Drowsiness
Fatigue
Weakness
Diarrhea or constipation
Heartburn
Decreased appetite
Trouble sleeping

This is not an exhaustive list of possible side effects. If you have questions or concerns, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.

Before Taking This Medication: Important Information to Share with Your Doctor

It is essential to inform your doctor about the following:

Any allergies you have, including allergies to this medication, any of its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you are currently taking another medication that contains the same active ingredient as this drug.
* If you are taking apomorphine, as this may interact with this medication.

Please note that this is not an exhaustive list of all potential interactions. To ensure your safety, it is crucial to disclose all of your medications, including prescription and over-the-counter drugs, natural products, and vitamins, as well as any health problems you may have. Your doctor and pharmacist need this information to determine whether it is safe for you to take this medication in conjunction with your other medications and health conditions.

Remember, do not start, stop, or change the dosage of any medication without first consulting your doctor to confirm that it is safe to do so.

It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Until you understand how this drug affects you, avoid operating a vehicle and engaging in other activities that require your full attention and alertness. If you are pregnant, planning to become pregnant, or are currently breast-feeding, notify your doctor. You and your doctor will need to discuss the potential benefits and risks of this medication to both you and your baby.

• Apomorphine (increased risk of severe hypotension and loss of consciousness)
• QT-prolonging drugs (e.g., amiodarone, sotalol, quinidine, procainamide, disopyramide, dofetilide, cisapride, pimozide, thioridazine, ziprasidone, moxifloxacin, erythromycin, haloperidol, methadone, tricyclic antidepressants) - increased risk of QT prolongation and Torsade de Pointes.
• Serotonergic drugs (e.g., SSRIs, SNRIs, TCAs, MAOIs, triptans, fentanyl, lithium, tramadol, St. John's Wort) - increased risk of serotonin syndrome.

• CYP3A4 inducers (e.g., rifampin, carbamazepine, phenytoin, phenobarbital) - may decrease granisetron plasma concentrations.
• CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, clarithromycin, ritonavir) - may increase granisetron plasma concentrations.

• Nausea
• Vomiting
• Headache
• Constipation
• Diarrhea
• Dizziness
• Fatigue
• Signs of serotonin syndrome (agitation, confusion, rapid heart rate, fever, sweating, muscle rigidity, tremors, twitching, loss of coordination, seizures)
• Signs of QT prolongation (palpitations, dizziness, syncope)

Granisetron is Pregnancy Category B. Animal studies have not shown harm to the fetus, but there are no adequate and well-controlled studies in pregnant women. Use only if clearly needed.

It is not known whether granisetron is excreted in human milk. Caution should be exercised when granisetron is administered to a nursing mother. Consider the benefits of breastfeeding versus the potential risks to the infant.

Oral tablets are approved for adolescents 12 years and older for CINV. IV formulation is used in younger children. Dosing is weight-based for IV, and adult dosing for oral in adolescents. Safety and efficacy in children under 2 years have not been established.

No specific dose adjustment is required based on age alone. However, elderly patients may have reduced renal or hepatic function, which could affect drug clearance. Monitor for adverse effects and consider comorbidities and concomitant medications.

• Granisetron is generally well-tolerated. Common side effects include headache and constipation.
• Administer the first dose approximately 1 hour before chemotherapy to ensure adequate plasma levels at the onset of emetogenic stimuli.
• While generally safe, be mindful of potential QT prolongation, especially in patients with pre-existing cardiac conditions, electrolyte imbalances, or those on other QT-prolonging medications.
• Monitor for signs of serotonin syndrome if co-administered with other serotonergic agents.
• Oral granisetron is effective for moderately emetogenic chemotherapy and for delayed CINV.

• Ondansetron (Zofran)
• Palonosetron (Aloxi)
• Dolasetron (Anzemet)
• Netupitant/Palonosetron (Akynzeo)
• Rolapitant (Varubi)
• Dexamethasone (corticosteroid)
• NK1 receptor antagonists (e.g., aprepitant, fosaprepitant)
• Olanzapine (atypical antipsychotic with antiemetic properties)

If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe and effective treatment, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so it is a good idea to consult with your pharmacist. If you have any questions or concerns about this medication, do not hesitate to discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide detailed information about the overdose, including the medication taken, the amount, and the time it occurred.