Indications 

Kytril is a prescription medicine indicated for the prevention of: 

• Nausea and vomiting related to emetogenic cancer therapy (initial and repeat courses, including high-dose cisplatin) 
• Nausea and vomiting caused by radiation (including total body irradiation and fractionated abdominal radiation) 

Classified as a 5-HT3 receptor antagonist, Kytril functions by inhibiting serotonin, a natural body compound that triggers nausea and vomiting. 

Uses and Dosage 

Before taking Kytril and with each prescription refill, thoroughly review its medication guide and patient information leaflet. Consult your physician or pharmacist if you have any inquiries or concerns. 

Kytril is typically administered only on the day of chemotherapy or radiation treatment. 

The usual recommended dosage of this medication is either 2 mg once daily or 1 mg twice daily. 

• In the once-daily regimen, two 1 mg tablets are administered up to 1 hour before chemotherapy or radiation. 
• In the twice-daily regimen, the initial 1 mg tablet is given within a maximum of 1 hour prior to chemotherapy, while the second tablet is administered 12 hours following the initial dose. 

Take Kytril exactly as directed. Avoid taking more or less of it or more frequently than your doctor prescribes. 

Inform your doctor if your condition persists or deteriorates. 

Side Effects 

Listed below are the potential adverse effects of Kytril. Inform your doctor right away if any of them last or worsen. 

Common Side Effects 

• Headache or weakness 
• Diarrhea or constipation 
• Stomach pain, indigestion, or loss of appetite 
• Sleep problems, such as insomnia 

• Fever or flu-like symptoms 

Serious Side Effects 

• Headache accompanied by chest pain, severe dizziness, fainting, or rapid and forceful heartbeats 
• Indication of increased blood pressure: 
  • Severe headache 
  • Ringing in the ears 
  • Anxiety 
  • Confusion 
  • Shortness of breath 
• Indication of high levels of serotonin in the body: 
  • Restlessness 
  • Hallucinations 
  • Fever 
  • Rapid heartbeat 
  • Heightened reflexes 
  • Nausea 
  • Vomiting 
  • Diarrhea 
  • Impaired coordination 
  • Fainting 

Call your doctor at once if you experience any of the severe side effects listed above. 

Allergic Reactions 

Severe allergic reactions to Kytril are uncommon; however, seek immediate medical attention if you experience symptoms such as: 

• Hives 
• Difficult breathing 
• Swelling of the face, lips, tongue, or throat 

This list does not contain all the potential side effects of Kytril. If you experience any unlisted effects, inform your physician promptly. 

Cautions 

Before taking Kytril, inform your doctor and pharmacist if you have any known hypersensitivities, especially to granisetron, other medications, or any ingredient in Kytril tablets. 

To ensure Kytril is safe for you, disclose to your physician your medical background, specifically: 

• Any pre-existing liver disease 
• Heart rhythm disorder 
• Electrolyte imbalance (e.g., low levels of potassium or magnesium in the blood) 
• Personal/family history of long QT syndrome 

Other drugs may interact with Kytril, including apomorphine. Tell your doctor and pharmacist all your medicines, including prescription and over-the-counter drugs, other dietary supplements, and herbal products, to lower the risk of such drug interactions. 

The likelihood of serotonin syndrome toxicity rises with concurrent use of drugs that boost serotonin levels, including illicit substances like MDMA, St. John’s wort, and specific antidepressants (e.g., fluoxetine, paroxetine, duloxetine, venlafaxine). The risk may heighten during initial administration or dosage escalation. 

Kytril has the potential to induce a heart rhythm condition called QT prolongation. In rare cases, QT prolongation can lead to severe symptoms (e.g., fast/irregular heartbeat, fainting) that require immediate medical attention, as they can be serious or even fatal. 

The use of Kytril during pregnancy is only recommended when there is a clear necessity. Consult with your doctor about the risks and benefits of taking this medication. 

The excretion of granisetron in human milk is not known. Consult your doctor before taking this medication when nursing an infant.