granisetron

Action and Spectrum

Actions and Spectrum: 

granisetron is a medication that belongs to a class of drugs known as selective serotonin (5-HT3) receptor antagonists. It is primarily used for the prevention and treatment of nausea and vomiting caused by chemotherapy, radiation therapy, and surgery. The actions of granisetron are achieved by blocking the action of serotonin, a neurotransmitter that is involved in the regulation of nausea and vomiting.

Specifically, granisetron works by blocking the 5-HT3 receptors in the central nervous system and gastrointestinal tract, thereby reducing the activity of the vomiting reflex and reducing the frequency and severity of nausea and vomiting.

The spectrum of granisetron’s effects includes the prevention and treatment of acute and delayed nausea and vomiting caused by chemotherapy, radiation therapy, and surgery. It is effective in both adults and children. 

Drug Interaction

Adverse Reaction

Adverse Reactions 

>10% 

Headache  

1-10% 

Diarrhea  

Constipation  

Asthenia  

Somnolence  

Sedation  

Drowsiness 

Frequency not defined 

Anxiety 

Fatigue 

Increased LFTs 

Malaise 

Black Box Warning

Contraindication / Caution

Contraindication/Caution: 

Contraindications: 

• Hypersensitivity to granisetron or any component of the formulation 
• Use with apomorphine due to the risk of severe hypotension and loss of consciousness 

Caution should be exercised when using granisetron in the following situations: 

• Patients with a history of heart disease or arrhythmias 
• Patients with electrolyte imbalances or who are taking medications that can cause electrolyte imbalances 
• Patients with liver or kidney impairment 
• Pregnant or breastfeeding women 

Pregnancy / Lactation

Pregnancy consideration:  

Category B 

Breastfeeding warnings: granisetron is not known for its excretion in breast milk; therefore, take it with caution 

Pregnancy category: 

• Category A: Satisfactory and well-controlled studies show no risk to the fetus in the first or later trimester. 
• Category B: There is no affirmation of risk to the fetus found in animal reproduction studies, and there are not enough studies on pregnant women. 
• Category C: Adverse effects on the fetus found with evidence in animal reproduction studies and no adequate evidence for a product in humans; Pregnant women must take care of the potential risks. 
• Category D: There is adequate data available with sufficient evidence of human fetal risk from various platforms. However, despite potential dangers may be used only in emergency cases for potential benefits. 
• Category X: Drugs listed in this category outweigh risks over benefits. The drug is not for pregnant women. 
• Category N: No data is available for the drug under this category. 

Pharmacology

Pharmacology: 

granisetron is a medication that belongs to a class of drugs known as selective serotonin (5-HT3) receptor antagonists. It works by blocking the action of serotonin, a neurotransmitter that is involved in the regulation of nausea and vomiting. 

Specifically, granisetron blocks the 5-HT3 receptors in the central nervous system and gastrointestinal tract, thereby reducing the activity of the vomiting reflex and reducing the frequency and severity of nausea and vomiting. 

Pharmacodynamics: 

granisetron is a medication that works as a selective serotonin (5-HT3) receptor antagonist. It blocks the action of serotonin, a neurotransmitter that is involved in the regulation of nausea and vomiting. 

The 5-HT3 receptors are found in both the central nervous system and the gastrointestinal tract and are involved in the control of nausea and vomiting. By blocking these receptors, granisetron reduces the activity of the vomiting reflex and decreases the frequency and severity of nausea and vomiting. 

granisetron is a highly selective antagonist of the 5-HT3 receptors, meaning it has a high affinity for these receptors and does not interact significantly with other receptor types. This selectivity is important because it allows granisetron to block the 5-HT3 receptors specifically without affecting other physiological processes in the body. 

Pharmacokinetics: 

Absorption 

The half-life is 3-14 hours 

Time for onset of action is 4-10 min (IV) 

Duration of action is 24 hours (IV) 

The bioavailability is 60% (PO) 

Distribution 

The release rate for patch is 3.1 mg/24 hr 

The protein bound is 65% 

The volume of distribution is 2-4 L/kg 

Metabolism 

The drug is extensively metabolized in the liver through oxidation, N-demethylation, conjugation, and CYP3A subfamily 

Inactive metabolites are formed 

The rate of total body clearance is 0.2-0.79 L/hr/kg 

Elimination and Excretion 

The drug is excreted 38% in feces and 60% in urine 

Adminstartion

Administration 

granisetron can be administered by several routes, including orally, intravenously, and subcutaneously. The route of administration depends on the patient’s condition and the purpose of the medication. 

Oral administration: 

granisetron is available as an oral tablet or oral solution. The tablets are usually taken with or without food, and should be swallowed whole with a glass of water. The oral solution should be measured carefully using a dosing syringe or spoon and can be taken with or without food. The dosage and frequency of oral administration will vary depending on the patient’s condition and medical history. 

Intravenous administration: 

granisetron can also be given as an intravenous injection or infusion. The intravenous route is often used in hospital settings for patients who are experiencing severe nausea and vomiting, such as those undergoing chemotherapy or radiation therapy. The medication is usually administered over a period of 30 seconds to 5 minutes, and the dose and frequency will depend on the patient’s condition and medical history. 

Subcutaneous administration: 

In some cases, granisetron may be administered subcutaneously, which involves injecting the medication under the skin using a syringe. This route of administration may be used for patients who cannot tolerate oral medications or intravenous injections. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: granisetron 

Pronounced: gra-NIS-e-tron 

Why do we use granisetron? 

granisetron is a medication that is primarily used to prevent and treat nausea and vomiting caused by chemotherapy, radiation therapy, and surgery. It works by blocking the action of serotonin, a neurotransmitter that is involved in the regulation of nausea and vomiting. 

Chemotherapy and radiation therapy are known to cause significant nausea and vomiting, which can be difficult to manage and can have a negative impact on a patient’s quality of life. granisetron is highly effective in preventing and treating these symptoms, both in the acute and delayed phases. 

In addition to its use in cancer treatment, granisetron may also be used to prevent and treat nausea and vomiting caused by other conditions or medications, such as post-operative nausea and vomiting, gastroenteritis, and certain medications used in anesthesia.