Anthropometric Measurements as Predictors of Low Birth Weight Among Tanzanian Neonates: A Hospital-Based Study
November 7, 2025
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Brand Name :
No Data Available.
Synonyms :
ondansetron
Class :
Antiemetics; Selective 5-HT3 Antagonist
Brand Name :
No Data Available.
Synonyms :
ondansetron
Class :
Antiemetics; Selective 5-HT3 Antagonist
Dosage forms & StrengthsÂ
TabletÂ
4mgÂ
8mgÂ
24mgÂ
Oral solutionÂ
4mg/5 mlÂ
Orally disintegrating tabletsÂ
4mgÂ
8mgÂ
Oral soluble filmÂ
4mgÂ
8mgÂ
Injectable solutionÂ
2mg/mlÂ
Chemotherapy Induced Vomiting And NauseaÂ
ondansetron is meant for prophylactic treatment of nausea and vomiting due to chemotherapy
Moderate condition- 8 mg orally 30 minutes before starting chemotherapy.
Later every 12 hours for a couple of days after chemotherapy
Severe condition- 24 mg orally 30 minutes before starting chemotherapy
For intravenous dose- 0.15 mg/kg for 15 minutes should be administered half an hour before chemotherapy. Second dose 4-8 hours later, do not exceed the dose more than 16 mg
Postoperative Nausea/vomitingÂ
ondansetron is meant for prophylaxis of nausea and vomiting caused after surgery
4 mg intravenously or intramuscularly right before the anesthesia, or
16 mg orally every hour before induction of anesthesia
Patients with body weight more than 80 kg need an additional 4 mg intravenous dose
ondansetron is meant for prophylaxis of nausea and vomiting caused due to radiation
In the case of total body radiation therapy- 8 mg orally 1-2 hours before the radiation exposure. Later administer the doses every 8 hours for 1-2 days
For single dose fraction- Administer 8 mg orally 1-2 hours before the radiotherapy
Continue the dose every 8 hours after the therapy
Daily abdominal fraction- 8 mg orally 1-2 hours before radiotherapy
Continue the dose every 8 hours after every radiotherapy
Dose Modifications
In case of severe hepatic impairment or a score more than 10 for Child Pugh, do not exceed the dose more than 8 mg per day
Cholestatic Pruritis
(Off-label)
8 mg orally every 12 hours for 7 days till 5 months
Secondly, 4-8 mg intravenously as a short-term intermittent dosing used in the adults
Single dose of 4 mg can be used in pregnancy
Uremic Pruritus
(Off-label)
8 mg orally every 12 hours, or
8 mg orally every 8-12 hours for 14 days until 5 months
Spinal Opioid-Induced Pruritus
(Off-label)
4-8 mg intravenously, 20-30 minutes prior to the therapy
Repeat the dose at 12, 24, 36 and 48 hours as required
(Off-label)
4-8 mg orally every 12 hours for 3 weeks
Secondly, 12 mg intravenously for 4 days
Chemotherapy Induced Vomiting And NauseaÂ
For prophylactic treatment
In children <4 years: Safety and efficacy are not seen
For 4-12 years: 4 mg, 30 minutes before chemotherapy, 4 and 8 hours after 1st dose, then every 8 hours for 1-2 days post chemotherapy
For more than 12 years: 8 mg 30 minutes before starting chemotherapy, later every 12 hours for 1-2 days post chemotherapy, or
A single dose 24 mg orally
For <6 months: Safety and efficacy are not seen
For ≥6 months: 0.15 mg/kg over 15 minutes, half an hour prior to chemotherapy,
Repeat 4 to 8 hours after the first dose
Do not exceed more than 16 mg/dose
(Due to increased risk of QT prolongation 32 mg dose is not recommended)
Postoperative Nausea/vomitingÂ
Prophylaxis
Age 0.1-12 years
For<40 kg, 0.1 mg/kg intravenously
For >40 kg, 4 mg intravenously
Age>12 years
4 mg intravenously or intramuscularly right before anesthesia or post the procedure, or
16 mg orally an hour before anesthesia; for patients >80 kg an additional of 4 mg intravenously is preferred
Dosage forms & StrengthsÂ
TabletÂ
4mgÂ
8mgÂ
Oral solutionÂ
4mg/5 mlÂ
Orally disintegrating tabletsÂ
4mgÂ
8mgÂ
Oral soluble filmÂ
4mgÂ
8mgÂ
Injectable solutionÂ
2mg/mlÂ
Chemotherapy Induced Vomiting And NauseaÂ
For prophylactic treatment:
In children <4 years: Safety and efficacy are not seen
For 4-12 years: 4 mg, 30 minutes before chemotherapy, 4 and 8 hours after 1st dose, then every 8 hours for 1-2 days post chemotherapy
For more than 12 years: 8 mg 30 minutes before starting chemotherapy, later every 12 hours for 1-2 days post chemotherapy, or
a single dose 24 mg orally
For <6 months: Safety and efficacy are not seen
For ≥6 months: 0.15 mg/kg over 15 minutes, half an hour prior to chemotherapy,
Repeat 4 to 8 hours after the first dose
Do not exceed more than 16 mg/dose (Due to increased risk of QT prolongation 32 mg dose is not recommended)
Refer to the adult dosingÂ
ondansetron: they may increase the QTc-prolonging effect of QTc-prolonging Agents
ondansetron: they may increase the QTc-prolonging effect of QTc-prolonging Agents
may affect the absorption of drugs when combined
may affect the absorption of drugs when combined
may affect the absorption of drugs when combined
may affect the absorption of drugs when combined
may affect the absorption of drugs when combined
it may decrease the serum concentration of belumosudil
it may decrease the serum concentration of bosutinib
may decrease the serum concentration
belumosudil: they may diminish the serum concentration of Inhibitors of the Proton Pump
technetium Tc-99m tetrofosminÂ
may decrease the diagnostic effect of each other when combined
antiemetics increase the hypotensive effect of apomorphine
it increases the QTc prolongation of ondansetron
QTc interval is increased both by lenvatinib and ondansetron
both lapatinib and ondansetron increase the QTc interval
CYP3A strong enhancers of the small intestine may reduce the bioavailability of ondansetron
may decrease the serum concentration
it increases the QTc prolongation of ondansetron
ondansetron enhances the concentration of ondansetron in serum
ondansetron decreases the analgesia of tapentadol
ondansetron increases the serotonergic effect of tramadol
it may diminish the therapeutic effect of Immune Checkpoint Inhibitors
it may diminish the therapeutic effect of Immune Checkpoint Inhibitors
it may diminish the therapeutic effect of Immune Checkpoint Inhibitors
may diminish the therapeutic effect of bisphosphonate derivative
may diminish the therapeutic effect of bisphosphonate derivative
may diminish the therapeutic effect of bisphosphonate derivative
may diminish the therapeutic effect of bisphosphonate derivative
may enhance the Qtc prolonging effect
may enhance the Qtc prolonging effect
may enhance the Qtc prolonging effect
may enhance the Qtc prolonging effect
may enhance the Qtc prolonging effect
may diminish the therapeutic effect of bisphosphonate derivatives
may diminish the therapeutic effect of bisphosphonate derivatives
may diminish the therapeutic effect of bisphosphonate derivatives
may diminish the therapeutic effect of bisphosphonate derivatives
it increases the concentration of metformin in the serum
may diminish the therapeutic effect of immune checkpoint inhibitors
may diminish the therapeutic effect of immune checkpoint inhibitors
may diminish the therapeutic effect of immune checkpoint inhibitors
Inhibitors of the Proton Pump: they may decrease the therapeutic effect of oral bisphosphonate derivatives
Inhibitors of the Proton Pump: they may decrease the therapeutic effect of oral bisphosphonate derivatives
Inhibitors of the Proton Pump: they may decrease the therapeutic effect of oral bisphosphonate derivatives
Inhibitors of the Proton Pump: they may decrease the therapeutic effect of oral bisphosphonate derivatives
Inhibitors of the Proton Pump: they may decrease the therapeutic effect of oral bisphosphonate derivatives
may have an increased QTc-prolonging effect when combined with ondansetron
may have an increased QTc-prolonging effect when combined with ondansetron
may have an increased QTc-prolonging effect when combined with ondansetron
may have an increased QTc-prolonging effect when combined with ondansetron
Combining ondansetron with pranlukast may cause a reduction in the ondansetron’s metabolism
The potential for increased CNS depression risk or seriousness occurs when ondansetron is used together with pipecuronium
It may enhance the risk of adverse effects when combined with Proton pump inhibitors
It may enhance the risk of adverse effects when combined with Proton pump inhibitors
It may enhance the risk of adverse effects when combined with Proton pump inhibitors
may have an increased serotonergic effect when combined with serotonergic agents
dihydroartemisinin/piperaquineÂ
combination of dihydroartemisinin/piperaquine with ondansetron will have QTc prolongation
the effect of ondansetron is decreased by lorlatinib, by altering intestinal or hepatic CYP3A4 enzyme metabolism
it increases the QTc-prolonging ability of QT-prolonging kinase inhibitors
Proton Pump inhibitors may increase the absorption of amphetamine
l-methylfolate-pyridoxal 5′-phosphate-methylcobalamine
it may decrease the serum concentration of Multivitamins
it may decrease the serum concentration of Minerals
it may decrease the serum concentration of Minerals
it may decrease the serum concentration of Minerals
it may decrease the serum concentration of Minerals
it may decrease the serum concentration of Minerals
may increase the serum concentration of itraconazole
they decrease the efficacy of cysteamine
the rate of metabolism may be altered
it increases the QTc prolongation effect of ondansetron
nafcillin will decrease the effect of action of ondansetron by decreasing renal clearance.
domperidone increases the QTc prolongation of ondansetron
Actions and Spectrum:Â
ondansetron is a medication that is primarily used to prevent and treat nausea and vomiting in a variety of settings, including:Â
ondansetron has a broad spectrum of activity against different types of nausea and vomiting, including acute and delayed nausea, and vomiting, anticipatory nausea and vomiting, and breakthrough nausea and vomiting. It is particularly effective against nausea and vomiting induced by chemotherapy and radiation therapy and is often considered a first-line treatment in these settings.Â
Adverse ReactionsÂ
>10%Â
Headache Â
Malaise Â
1-10%Â
Hypoxia Â
Drowsiness Â
Diarrhea Â
Dizziness Â
Fever Â
Gynecologic disorder Â
Anxiety Â
Urinary retention Â
Pruritus Â
Injection-site pain Â
Paresthesia Â
Cold sensation Â
Frequency not definedÂ
NauseaÂ
ArrhythmiasÂ
HiccupsÂ
Blurred visionÂ
ArthralgiaÂ
UrticariaÂ
BronchospasmÂ
Hepatic necrosisÂ
Ondansetron is commonly prescribed to prevent nausea and vomiting, but it is associated with important cardiac safety concerns. Although it does not carry an official black box warning, clinical evidence has shown that the drug can cause changes in the electrocardiogram (ECG), particularly prolongation of the QT interval. In some cases, this has led to the development of Torsades de Pointes, a rare but potentially life-threatening arrhythmia. Due to these risks, the use of a single 32 mg intravenous dose of ondansetron is no longer recommended. Furthermore, the FDA advises against using ondansetron in patients with congenital long QT syndrome, as they are particularly vulnerable to serious cardiac complications.Â
Contraindication/Caution:Â
ondansetron is generally considered safe and well-tolerated, but there are some situations where it may not be appropriate, or caution should be exercised:Â
Pregnancy consideration:Â Â
ondansetron can only be used by pregnant females if there is no other option availableÂ
Breastfeeding warnings: ondansetron should be taken by lactating females only if the potential benefits outweigh the potential risksÂ
Pregnancy category:Â
Pharmacology:Â
ondansetron is a selective serotonin 5-HT3 receptor antagonist, which means it blocks the action of serotonin at the 5-HT3 receptor in the central nervous system (CNS) and in the gastrointestinal tract. Serotonin is a neurotransmitter that can trigger nausea and vomiting when it binds to the 5-HT3 receptor in the CNS and in the gut.Â
By blocking the 5-HT3 receptor, ondansetron prevents the transmission of signals that cause nausea and vomiting. This results in reduced nausea and vomiting in individuals undergoing chemotherapy, radiation therapy, or surgery, or in those taking medications that can cause nausea and vomiting.Â
Pharmacodynamics:Â
The pharmacodynamics of ondansetron involves its interaction with serotonin 5-HT3 receptors in the central nervous system (CNS) and the gastrointestinal (GI) tract. In the CNS, ondansetron binds selectively to 5-HT3 receptors, which are primarily located in the chemoreceptor trigger zone (CTZ) of the brainstem.
The CTZ is a site that can detect circulating toxins and other substances in the blood, triggering the sensation of nausea and vomiting. By blocking 5-HT3 receptors in the CTZ, ondansetron inhibits the transmission of signals that trigger nausea and vomiting, leading to its antiemetic effects.Â
In the GI tract, 5-HT3 receptors are located on vagal afferent fibers, which transmit signals to the CNS that can induce nausea and vomiting. ondansetron also blocks these receptors, reducing the sensation of nausea and preventing the vomiting reflex.Â
Pharmacokinetics:Â
AbsorptionÂ
The bioavailability is 56-71% for oral; extent of absorption increases with food (17%)Â
Time for the onset of action is 30 minutesÂ
The peak plasma concentration is achieved at the end of infusion for IV administration. Â
It takes 30 minutes for intramuscular and 1-2 hours for oral Â
DistributionÂ
The protein bound is 70-76%Â
The volume of distribution is 1.7-3.7 L/kg for children; and 2.2-2.5 L/kg for adults Â
MetabolismÂ
The drug is metabolized extensively in the liverÂ
Elimination and ExcretionÂ
The half-life is 2-7 hours for children <15 years and 3-7 hours for adultsÂ
The rate of renal clearance is 0.26-0.38 L/hr/kgÂ
The rate of total body clearance is 600-700 mL/minÂ
The drug is excreted (30-70%) primarily in urine; and 25% in feces
Administration:Â
Patient information leafletÂ
Generic Name: ondansetronÂ
Pronounced: on-dan-setronÂ
Why do we use ondansetron?Â
ondansetron is a medication used to prevent and treat nausea and vomiting, particularly in people undergoing chemotherapy, radiation therapy, or surgery. It is also used to prevent nausea and vomiting caused by certain medications, such as opioids. ondansetron works by blocking the action of serotonin, a chemical in the brain that can trigger nausea and vomiting. It belongs to a class of medications called serotonin 5-HT3 receptor antagonists.Â
ondansetron is often preferred over other medications for nausea and vomiting because it has fewer side effects, such as drowsiness, than other medications in its class. It can be taken orally as a tablet or liquid or administered intravenously (IV) in a hospital or clinical setting. It is important to follow the dosing instructions provided by a healthcare provider and to report any side effects or concerns to them.Â
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