Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Zofran ODT (Ondansetron). If you are concerned about side effects, discuss the risks and benefits of Zofran ODT (Ondansetron) with your doctor.

The following side effects have been reported by at least 1% of people taking Zofran ODT (Ondansetron). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• Constipation
• flushing or feeling warm
• headache
• hiccups
• Low Blood Pressure
• unusual tiredness or weakness

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• blurred vision
• difficulty moving or abnormal body movement
• dizziness
• pain, redness, or burning at place of injection
• rapid pounding heartbeat

Stop taking the medication and seek immediate medical attention if any of the following occur:

• seizures
• signs of a serious allergic reaction (i.e., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of heart problems (e.g., fast, irregular heartbeat or pulse, chest pain, sudden weight gain, difficulty breathing, leg swelling)
• signs of serotonin syndrome (e.g., agitation, confusion, mood changes, decreased coordination, hallucinations, Fever, sweating)
• signs of a severe skin reaction (e.g., a rash combined with fever or discomfort, a rash covering a large area of the body, a rash that spreads quickly, blistering, peeling)
• temporary blindness

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Zofran ODT (Ondansetron).

Zofran

Injection

Each mL contains Zofran ODT (Ondansetron) 2 mg/mL (as hydrochloride dihydrate) for IV use. Nonmedicinal ingredients: citric acid monohydrate, methyl- and propylparaben (vials only), sodium citrate, and sodium chloride.

Oral Solution

Each 5 mL contains Zofran ODT (Ondansetron) 4 mg (as hydrochloride dihydrate). Nonmedicinal ingredients: citric acid, sodium citrate dihydrate, sodium benzoate, sorbitol solution, and strawberry flavour. Sucrose-free. Sweetened with sorbitol.

Tablets

4 mg
Each oval-shaped, yellow, film-coated tablet, engraved "4" on one side and "GLAXO" on the other, contains Zofran ODT (Ondansetron) 4 mg (as hydrochloride dihydrate). Nonmedicinal ingredients: lactose, magnesium stearate, hydroxypropyl methylcellulose, microcrystalline cellulose, opadry yellow or opaspray yellow (containing titanium dioxide and iron oxide yellow), and pregelatinized starch. Gluten- and tartrazine-free.

8 mg
Each oval-shaped, yellow, film-coated tablet, engraved "8" on one side and "GLAXO" on the other, contains Zofran ODT (Ondansetron) 8 mg (as hydrochloride dihydrate). Nonmedicinal ingredients: lactose, magnesium stearate, hydroxypropyl methylcellulose, microcrystalline cellulose, opadry yellow or opaspray yellow (containing titanium dioxide and iron oxide yellow), and pregelatinized starch. Gluten- and tartrazine-free.

Zofran ODT

4 mg
Each white, round, plano-convex, orally disintegrating tablet, with no markings on either side, contains Zofran ODT (Ondansetron) (base) 4 mg. Nonmedicinal ingredients: aspartame, gelatin, mannitol, sodium methyl hydroxybenzoate, sodium propyl hydroxybenzoate, and strawberry flavour.

8 mg
Each white, round, plano-convex, orally disintegrating tablet, with no markings on either side, contains Zofran ODT (Ondansetron) (base) 8 mg. Nonmedicinal ingredients: aspartame, gelatin, mannitol, sodium methyl hydroxybenzoate, sodium propyl hydroxybenzoate, and strawberry flavour.

Do not take Zofran ODT (Ondansetron) if you:

• are allergic to Zofran ODT (Ondansetron) or any ingredients of the medication
• are taking the medication Apomorphine

There may be an interaction between Zofran ODT (Ondansetron) and any of the following:

• alpha-blockers (e.g., Alfuzosin, Doxazosin, Tamsulosin)
• Amiodarone
• antipsychotics (e.g., chlorpromazine, Clozapine, Haloperidol, Olanzapine, pimozide, Quetiapine, Risperidone)
• Apalutamide
• apomorphine
• "azole" antifungals (e.g., fluconazole, itraconazole, ketoconazole, Voriconazole)
• barbiturates (e.g., pentobarbital, Phenobarbital)
• Bosentan
• Bromocriptine
• Buspirone
• Carbamazepine
• Carvedilol
• chloroquine
• Cobicistat
• Cyclobenzaprine
• Cyclosporine
• Deferasirox
• Degarelix
• Dexamethasone (systemic)
• Dipyridamole
• Disopyramide
• dofetilide
• Domperidone
• Dronedarone
• Enzalutamide
• ergot alkaloids (e.g., ergotamine, Dihydroergotamine)
• Flecainide
• Flibanserin
• formoterol
• grapefruit juice
• Hepatitis C antivirals (e.g., daclatasvir, ledipasvir)
• HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., delavirdine, efavirenz, etravirine, nevirapine)
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• lithium
• Lomitapide
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• Maprotiline
• mefloquine
• Metformin
• Methadone
• mifepristone
• Mirtazapine
• Mitotane
• Modafinil
• monoamine oxidase inhibitors (M.O.S. e.g., Moclobemide, Rasagiline, Selegiline, Tranylcypromine)
• Phenytoin
• primidone
• procainamide
• Propafenone
• Propranolol
• quinidine
• quinine
• quinolone antibiotics (e.g., ciprofloxacin, Norfloxacin, Ofloxacin)
• rifabutin
• rifampin
• rilpivirine
• Romidepsin
• St. John's wort
• saquinavir
• selective serotonin reuptake inhibitors (SSRIs; e.g., Citalopram, Fluoxetine, Paroxetine, Sertraline)
• serotonin/norepinephrine reuptake inhibitors (SNRIs; e.g., Desvenlafaxine, Duloxetine, Venlafaxine)
• other serotonin antagonist antiemetics (e.g., dolasetron, granisetron)
• siltuximab
• sotalol
• tacrolimus
• Tapentadol
• tenofovir
• Tetrabenazine
• Tocilizumab
• Tramadol
• Trazodone
• tricyclic antidepressants (e.g., Amitriptyline, Clomipramine, Desipramine, Trimipramine)
• "triptan" migraine medications (e.g., Rizatriptan, Sumatriptan, Zolmitriptan)
• Tryptophan
• tyrosine kinase inhibitors (e.g., Dabrafenib, imatinib, Nilotinib, Sunitinib)
• Vardenafil
• verapamil

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Zofran ODT (Ondansetron). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Zofran ODT (Ondansetron).

Allergy: People who have had an allergic reaction to Dolasetron or Granisetron are advised not to take Zofran ODT (Ondansetron). Before you take Zofran ODT (Ondansetron), inform your doctor about any previous adverse reactions you have had to medications. Contact your doctor at once if you experience signs of an allergic reaction such as skin rash, itching, difficulty breathing, or swelling of the face and throat.

Abnormal heart rhythms: Very rarely, Zofran ODT (Ondansetron) can affect the heart's electrical activity and cause an irregular heartbeat. This is more likely to happen with the injectable form of Zofran ODT (Ondansetron). Certain medications (e.g., Sotalol, quinidine, thioridazine, Chlorpromazine, Pimozide, moxifloxacin, Mefloquine, pentamidine, arsenic trioxide, probucol, Tacrolimus) can increase the risk of a type of abnormal heart rhythm called QT prolongation, and should not be used in combination with Zofran ODT (Ondansetron). You are more at risk for this type of abnormal heart rhythm and its complications if you:

• are female
• are older than 65 years of age
• have a family history of sudden cardiac death
• have a history of heart disease or abnormal heart rhythms
• have a slow heart rate
• have congenital prolongation of the QT interval
• have Diabetes
• have had a Stroke
• have low potassium, magnesium, or calcium levels
• have nutritional deficiencies

If you have heart disease and abnormal heart rhythms, or are taking certain medications (e.g., Verapamil, atazanavir), discuss with your doctor how Zofran ODT (Ondansetron) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Zofran ODT (Ondansetron), and whether any special monitoring is needed. Your doctor may monitor your heart rate using a test called an electrocardiogram (ECG) while you are using Zofran ODT (Ondansetron).

Liver function: Zofran ODT (Ondansetron) is broken down and removed from the body by the liver. Decreased liver function slows down the removal of the medication from the body and increases the risk of side effects from Zofran ODT (Ondansetron). If you have liver disease or reduced liver function, discuss with your doctor how Zofran ODT (Ondansetron) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Zofran ODT (Ondansetron), and whether any special monitoring is needed.

Motion Sickness: Zofran ODT (Ondansetron) is not effective for the treatment of motion sickness.

Neuroleptic malignant syndrome (NMS): Zofran ODT (Ondansetron), like other similar medications, can cause a potentially fatal syndrome known as neuroleptic malignant syndrome (NMS). If you notice the symptoms of NMS such as high fever, muscle stiffness, confusion or loss of consciousness, sweating, racing or irregular heartbeat, or fainting, get immediate medical attention.

Phenylketonuria: People with phenylketonuria (lacking the enzyme needed to break down phenylalanine) should take forms of Zofran ODT (Ondansetron) other than oral dissolving tablets (ODT). The ODT form of Zofran ODT (Ondansetron) contains aspartame, an ingredient that cannot be broken down in the body by people who have phenylketonuria.

Serotonin syndrome: Severe reactions are possible when Zofran ODT (Ondansetron) is combined with other medications that act on serotonin, such as tricyclic antidepressants and serotonin reuptake inhibitors, medications used to treat Depression. These combinations must be avoided. Symptoms of a reaction may include muscle rigidity and spasms, difficulty moving, and changes in mental state including delirium and agitation. Coma and death are possible.

Pregnancy: The safety of Zofran ODT (Ondansetron) for use by pregnant women has not been established. Zofran ODT (Ondansetron) should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking Zofran ODT (Ondansetron), contact your doctor immediately.

Breast-feeding: It is not known if Zofran ODT (Ondansetron) passes into breast milk. If you are a breast-feeding mother and are taking Zofran ODT (Ondansetron), it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Zofran ODT (Ondansetron) to treat nausea and vomiting caused by chemotherapy have not been established for children under 3 years of age. The safety and effectiveness of using Zofran ODT (Ondansetron) to treat nausea and vomiting caused by radiation or surgery have not been determined for children less than 18 years of age. Its use by this age group is not recommended.

Seniors: The safety and effectiveness of using Zofran ODT (Ondansetron) by people 65 years or older to treat nausea and vomiting caused by surgery have not been established. Seniors may be at an increased risk of developing irregular heart beat with Zofran ODT (Ondansetron), particularly the injectable form. Talk to your doctor about any concerns you may have.