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Side Effects > Ondansetron

Ondansetron Side Effects

Brand Names: Zofran, Zofran ODT

Please note - some side effects for Ondansetron may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA at http://www.fda.gov/medwatch/ or 1-800-FDA-1088 (1-800-332-1088).


Side Effects of Ondansetron - for the Consumer

Ondansetron

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Ondansetron:

Constipation; diarrhea; dizziness; drowsiness; headache; irritation, redness, pain, or burning at the site of injection; tiredness.

Seek medical attention right away if any of these SEVERE side effects occur when using Ondansetron:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); chest pain; fever; skin tingling or numbness; trouble urinating; vision changes or loss.

Ondansetron Orally Disintegrating Tablets

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Ondansetron Orally Disintegrating Tablets:

Constipation; diarrhea; dizziness; drowsiness; headache; tiredness; weakness.

Seek medical attention right away if any of these SEVERE side effects occur when using Ondansetron Orally Disintegrating Tablets:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); chest pain; fever; skin tingling or numbness; trouble urinating; vision change or loss.

Ondansetron Solution

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Ondansetron Solution:

Constipation; diarrhea; dizziness; drowsiness; headache; tiredness; weakness.

Seek medical attention right away if any of these SEVERE side effects occur when using Ondansetron Solution:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); chest pain; fever; skin tingling or numbness; trouble urinating; vision change or loss.

Ondansetron Tablets

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Ondansetron Tablets:

Constipation; diarrhea; dizziness; drowsiness; headache; tiredness; weakness.

Seek medical attention right away if any of these SEVERE side effects occur when using Ondansetron Tablets:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); chest pain; fever; skin tingling or numbness; trouble urinating; vision change or loss.

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Ondansetron Side Effects - for the Professional

Ondansetron

The following have been reported as adverse events in clinical trials of patients treated with Ondansetron, the active ingredient of Ondansetron hydrochloride. A causal relationship to therapy with Ondansetron hydrochloride has been unclear in many cases.

Chemotherapy-Induced Nausea and Vomiting

The adverse events in Table 5 have been reported in ≥5% of adult patients receiving a single 24-mg Ondansetron hydrochloride tablet in 2 trials. These patients were receiving concurrent highly emetogenic cisplatin-based chemotherapy regimens (cisplatin dose ≥50 mg/m2).

Table 5: Principal Adverse Events in US Trials: Single Day Therapy With 24 mg Ondansetron Hydrochloride Tablets (Highly Emetogenic Chemotherapy)
 

Event
 Ondansetron
24 mg. q.i.d.
n = 300
 Ondansetron
8 mg b.i.d
n = 124
 Ondansetron
32 mg q.i.d.
n = 117
 Headache  33 (11%)  16 (13%)  17 (15%)
 Diarrhea  13 (4%)  9 (7%)  3 (3%)

The adverse events in Table 6 have been reported in ≥5% of adults receiving either 8 mg of Ondansetron Hydrochloride Tablets 2 or 3 times a day for 3 days or placebo in 4 trials. These patients were receiving concurrent moderately emetogenic chemotherapy, primarily cyclophosphamide-based regimens.

Table 6. Principal Adverse Events in US Trials: 3 Days of Therapy with 8-mg Ondansetron Hydrochloride Tablets (Moderately Emetogenic Chemotherapy)
 
Event
 Ondansetron 8 mg b.i.d
n = 242
 Ondansetron 8 mg t.i.d
n = 415
 Placebo
n = 262
 Headache  58 (24%)  113 (27%)  34 (13%)
 Malaise/fatigue  32 (13%)  37 (9%)  6 (2%)
 Constipation  22 (9%)  26 (6%)  1 (<1%)
 Diarrhea  15 (6%)  16 (4%)  10 (4%)
 Dizziness  13 (5%)  18 (4%)  12 (5%)
Central Nervous System

There have been rare reports consistent with, but not diagnostic of, extrapyramidal reactions in patients receiving Ondansetron.

Hepatic

In 723 patients receiving cyclophosphamide-based chemotherapy in US clinical trials, AST and/or ALT values have been reported to exceed twice the upper limit of normal in approximately 1% to 2% of patients receiving Ondansetron Hydrochloride Tablets. The increases were transient and did not appear to be related to dose or duration of therapy. On repeat exposure, similar transient elevations in transaminase values occurred in some courses, but symptomatic hepatic disease did not occur. The role of cancer chemotherapy in these biochemical changes cannot be clearly determined.

There have been reports of liver failure and death in patients with cancer receiving concurrent medications including potentially hepatotoxic cytotoxic chemotherapy and antibiotics. The etiology of the liver failure is unclear.

Integumentary

Rash has occurred in approximately 1% of patients receiving Ondansetron.

Other

Rare cases of anaphylaxis, bronchospasm, tachycardia, angina (chest pain), hypokalemia, electrocardiographic alterations, vascular occlusive events, and grand mal seizures have been reported. Except for bronchospasm and anaphylaxis, the relationship to Ondansetron hydrochloride was unclear.

Radiation-Induced Nausea and Vomiting

The adverse events reported in patients receiving Ondansetron Hydrochloride Tablets and concurrent radiotherapy were similar to those reported in patients receiving Ondansetron Hydrochloride Tablets and concurrent chemotherapy. The most frequently reported adverse events were headache, constipation, and diarrhea.

Postoperative Nausea and Vomiting

The adverse events in Table 7 have been reported in ≥5% of patients receiving Ondansetron Hydrochloride Tablets at a dosage of 16 mg orally in clinical trials. With the exception of headache, rates of these events were not significantly different in the Ondansetron and placebo groups. These patients were receiving multiple concomitant perioperative and postoperative medications.

Table 7: Frequency of Adverse Events From Controlled Studies With Ondansetron Hydrochloride Tablets (Postoperative Nausea and Vomiting)
 
Adverse Event
 Ondansetron 16 mg
(n = 550)
 Placebo
(n = 531)
 Wound problem  152 (28%)  162 (31%)
 Drowsiness/sedation  112 (20%)  122 (23%)
 Headache  49 (9%)  27 (5%)
 Hypoxia  49 (9%)  35 (7%)
 Pyrexia  45 (8%)  34 (6%)
 Dizziness  36 (7%)  34 (6%)
 Gynecological disorder  36 (7%)  33 (6%)
 Anxiety /agitation  33 (6%)  29 (5%)
 Bradycardia  32 (6%)  30 (6%)
 Shiver(s)  28 (5%)  30 (6%)
 Urinary retention  28 (5%)  18 (3%)
 Hypotension  27 (5%)  32 (6%)
 Pruritus  27 (5%)  20 (4%)

Observed During Clinical Practice

In addition to adverse events reported from clinical trials, the following events have been identified during post-approval use of oral formulations of Ondansetron hydrochloride. Because they are reported voluntarily from a population of unknown size, estimates of frequency cannot be made. The events have been chosen for inclusion due to a combination of their seriousness, frequency of reporting, or potential causal connection to Ondansetron hydrochloride.

Cardiovascular

Rarely and predominantly with intravenous Ondansetron, transient ECG changes including QT interval prolongation have been reported.

General

Flushing. Rare cases of hypersensitivity reactions, sometimes severe (e.g., anaphylaxis/anaphylactoid reactions, angioedema, bronchospasm, shortness of breath, hypotension, laryngeal edema, stridor) have also been reported. Laryngospasm, shock, and cardiopulmonary arrest have occurred during allergic reactions in patients receiving injectable Ondansetron.

  •  Hepatobiliary: Liver enzyme abnormalities
  •  Lower Respiratory: Hiccups
  •  Neurology: Oculogyric crisis, appearing alone, as well as with other dystonic reactions
  •  Skin: Urticaria
  •  Special Senses: Eye Disorders: Cases of transient blindness, predominantly during intravenous administration, have been reported. These cases of transient blindness were reported to resolve with a few minutes up to 48 hours
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Side Effects by Body System

General

In general, headache is the most common adverse effect reported. Transient dizziness during or shortly after the IV infusion has also been reported during postmarketing experience.

Gastrointestinal

Gastrointestinal side effects including constipation (up to 15%) and diarrhea have been reported. Several cases of intestinal obstruction have been reported.

A causal relationship between intestinal obstruction and ondansetron has not been established.

Hepatic

Hepatic side effects have included mild elevations of liver function tests. The clinical significance of these elevations is unknown. Cases of jaundice have also been reported rarely. One case of pancreatitis was reported in a patient using ondansetron long-term. Liver failure and death have been reported in patients with cancer receiving concurrent medications, including potentially hepatotoxic cytotoxic chemotherapy and antibiotics, and intravenous ondansetron during postmarketing experience.

Cardiovascular

Cardiovascular side effects have rarely included angina and acute myocardial ischemia. Arrhythmias (including ventricular and supraventricular tachycardia, premature ventricular contractions, and atrial fibrillation), bradycardia, electrocardiographic alterations (including second-degree heart block, QT interval prolongation, and ST segment depression), palpitations, and syncope have been reported with the use of the intravenous ondansetron during postmarketing experience.

One study has suggested that prolongation of the QTc interval may occur in many patients treated with cisplatin and ondansetron simultaneously. In that study QTc prolongation occurred in 6 of 8 patients who received a combination of ondansetron and cisplatin. Five of the patients had prolongations of the QTc interval which were greater than 5%. However, no episodes of arrhythmia, hypotension, ischemia, congestive heart failure or other cardiovascular events were observed.

Similarly, results of a review of the cardiovascular effects of the drug class 5-hydroxytryptamine 3 receptor antagonists in the literature reported that electrocardiographic (ECG) changes were so small to be considered clinically insignificant. ECG changes were most noticeable between 1 to 2 hours after a dose of ondansetron and returned to baseline within 24 hours. To date, no serious cardiac side effects (including torsades de pointes) triggered by ECG interval changes have been connected with the use of 5-HT 3 receptor antagonists.

Hypersensitivity

Hypersensitivity side effects have rarely included rashes. Twenty-four reports of anaphylactoid-anaphylactic reactions following intravenous administration of ondansetron have been reported in postmarketing experience. One report suggests hypersensitivity reactions with 5-HT 3-antagonists may be a class effect and cross-reactive.

Psychiatric

A brief episode of ondansetron-induced depression has been reported in one woman whose depression was controlled with fluoxetine. A 41-year-old woman became suicidally depressed seven days after receiving ondansetron prior to arthroscopy. The depression was controlled with fluvoxamine, alprazolam, and flunitrazepam.

Psychiatric side effects have rarely included depression.

Dermatologic

Dermatologic side effects have included pruritus (5%) and rash (1%). A suspected fixed drug eruption with the lesions appearing macular and pruritic has also been reported. Rechallenge lead to regression of the lesions. Urticaria has been reported with the use of intravenous ondansetron during postmarketing experience.

Nervous system

Rechallenge with ondansetron lead to a reoccurrence of the opisthotonos in one patient. Patients with a history of drug-induced dystonic reactions may have a similar response after ondansetron therapy.

Nervous system side effects have included dizziness (18%) and extrapyramidal reactions, including twitching tremors, opisthotonos, severe jerking movements, and numbness. In many of these cases, diphenhydramine (25 mg to 50 mg) was effective for treatment or prevention. Oculogyric crisis, appearing alone, as well as with other dystonic reactions have also been reported with the use of intravenous ondansetron during postmarketing experience.

Ocular

Ocular side effects have rarely included blurred vision, in some cases associated with abnormalities of accommodation. Rare cases of transient blindness have also been reported, predominantly during intravenous administration.

Transient blindness (a duration of 2 to 3 minutes) generally resolved within 20 minutes up to 48 hours.

Respiratory

Respiratory side effects have included hiccups with the use of intravenous ondansetron during postmarketing experience.

Local

Local side effects have included pain, redness, and burning at injection site with the use of intravenous ondansetron during postmarketing experience.

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