Zofran Injection (Ondansetron)

Description

Indications

Ondansetron injection is utilized to prevent nausea and vomiting induced by cancer chemotherapy and surgery. Belonging to a class of medications known as serotonin 5-HT3 receptor antagonists, ondansetron operates by blocking the action of serotonin, a natural substance that has the potential to trigger nausea and vomiting. By inhibiting the serotonin receptors, ondansetron helps mitigate these symptoms, providing relief to individuals undergoing chemotherapy or surgery.

Uses and Dosage

To prevent nausea from chemotherapy, ondansetron is typically mixed in a solution and administered by injection into a vein as prescribed by your doctor. This administration usually takes place over 15 minutes and is initiated 30 minutes before the commencement of your chemotherapy treatment.

Adhere to the recommended speed and dose, as exceeding the prescribed limits may elevate the risk of serious side effects such as blurred vision or slowed/irregular heartbeat. The usual maximum single dose is 16 milligrams, and older adults are often prescribed a lower dose to minimize the risk of side effects. Depending on the chemotherapy treatment, additional doses may be administered 4 and 8 hours after the first dose, and you may be switched to an oral medication.

Your doctor may instruct you to continue using this medication for 1 or 2 days after your chemotherapy treatment. If used on a prescribed schedule, take it regularly at the same times each day for optimal benefits. Follow your doctor’s instructions precisely, avoiding the use of more medication or using it more frequently than prescribed.

If you are administering this medication to yourself at home, learn all preparation and usage instructions from your healthcare professional. When stored upright after initial use, clumps may occasionally form on the top of the vial. Check the vial carefully for particles, and if present, shake it to re-dissolve the particles. If any particles persist after shaking, do not use the liquid. Ondansetron injection should be clear and colorless. If you are using premixed bags, check for leaks, particles, or discoloration before use. If any of these issues are present, do not use the liquid. Familiarize yourself with proper storage and disposal procedures for medical supplies.

For the prevention or treatment of post-surgery nausea, a single dose of ondansetron may be given undiluted into a muscle or vein by a healthcare professional shortly before, during, or after surgery.

Dosage is determined based on factors such as weight, medical condition, age, and response to treatment.

Inform your doctor if your condition does not improve or worsens.

Side Effects

Some side effects may occur that usually do not need medical attention:

• headache
• constipation
• drowsiness
• feeling cold or chills
• pain, burning, numbness, or tingling in the hand or feet
• fever
• injection site pain, redness, swelling, warmth, or burning

Inform your healthcare provider immediately if you experience any serious side effects:

• rash
• hives
• itching
• swelling of the eyes, face, lips, tongue, throat, hands, feet, ankles, or lower legs
• hoarseness
• difficulty breathing or swallowing
• chest pain
• shortness of breath
• dizziness, light-headedness, or fainting
• fast, slow or irregular heartbeat
• blurred vision or vision loss
• lightheadedness
• agitation
• hallucinations (seeing things or hearing voices that do not exist)
• fever
• excessive sweating
• confusion
• nausea, vomiting, or diarrhea
• loss of coordination
• stiff or twitching muscles
• seizures

Caution

• Before using ondansetron, inform your doctor or pharmacist if you are allergic to it, other serotonin blockers (such as granisetron), or if you have any other allergies. Inactive ingredients in the product may cause allergic reactions or other issues.
• Prior to using this medication, disclose your medical history to your doctor or pharmacist, especially if you have an irregular heartbeat, liver disease, or stomach/intestinal problems.
• Ondansetron may lead to a condition affecting the heart rhythm known as QT prolongation, which can rarely cause serious (and rarely fatal) fast/irregular heartbeat and other symptoms like severe dizziness or fainting that require immediate medical attention.
• The risk of QT prolongation may increase if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using ondansetron, inform your doctor or pharmacist of all the drugs you are taking and whether you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), or a family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death). Low levels of potassium or magnesium in the blood may also elevate your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/”water pills”) or if you have conditions such as severe sweating, diarrhea, or vomiting. Discuss the safe use of ondansetron with your doctor.
• This drug may induce dizziness, drowsiness, or blurred vision. Alcohol or marijuana can intensify these effects. Avoid activities requiring alertness or clear vision until you can do them safely.
• Infants younger than 5 months may be more sensitive to the effects of this drug, especially diarrhea.
• Older adults may be more sensitive to the side effects of this drug, especially QT prolongation.
• During pregnancy, use this medication only when clearly necessary, as it may harm an unborn baby. Discuss the risks and benefits with your doctor.
• It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

Form and Strength

Zofran Injection is available in the following forms and strengths:

• Zofran Injection syrup:
  • 4 mg / 2 mL

FAQ

How fast does Zofran Injection work?

Zofran starts to work within minutes of infusion. An IV with Zofran offers quicker relief than an oral medication because it goes directly into the bloodstream rather than passing through the digestive tract first, allowing for maximum absorption.

Does a Zofran Injection make you sleepy?

Yes, Zofran might make you feel sleepy or tired. These are common side effects.

Resources

1. https://www.rxlist.com/zofran-injection-drug.htm
2. https://www.drugs.com/mtm/zofran-injection.html#:~:text=Yes%2C%20ondansetron%20(Zofran)%20might,placebo%20(an%20inactive%20treatment)
3. https://www.mayoclinic.org/drugs-supplements/ondansetron-injection-route/side-effects/drg-20065221?
4. https://medlineplus.gov/druginfo/meds/a606022.html
5. https://www.webmd.com/drugs/2/drug-7758/zofran-intravenous/details