How long does Zofran last? (3+ properties)

In this article, we will discuss how long Zofran (ondansetron) lasts. We will also discuss the factors affecting the duration of Zofran in the body, along with the possible side effects of Zofran. Additionally, we will provide you with some tips to use Zofran safely and effectively. 

How long does Zofran last? 

Zofran lasts in the body for about 8 hours. However, the elimination rate of Zofran may change depending on age, individual variability and underlying conditions. Zofran is an antiemetic drug which helps prevent nausea and vomiting. (1)

Zofran is used to manage nausea and vomiting associated with chemotherapy, radiation, postoperation and underlying disease conditions, which can cause nausea and vomiting. Zofran acts by inhibiting the action of selective 5-HT3 (serotonin) receptors both centrally and peripherally. Zofran also acts on the chemoreceptor trigger zone, which plays a role in producing nausea and vomiting. (1)

Zofran should be used under the guidance of a healthcare physician. Make sure you consult a physician for a thorough evaluation and treatment. 

What factors influence the duration of Zofran in your system?  

There are a few factors which can influence the time taken by Zofran to leave the body, such as (1,2)

Individual variability

Each individual reacts to the drug in a different manner. The metabolism and elimination of the drug varies among individuals. The enzyme activity has a significant impact on the efficiency of metabolism and elimination of the drug, which differs from person to person. Hence, some may experience prolonged effects of Zofran where, and some may not. 

Liver dysfunction

The liver plays an important role in metabolism. Individuals with liver impairment may metabolise Zofran slowly compared to a healthy individual, hence prolonging the time span of Zofran in the system. In severe hepatic impairment, Zofran should be used with caution, and the recommended daily dose should not be more than 8mg per day. (1)

Renal impairment

Zofran (ondansetron) is primarily eliminated through the kidney, and in individuals with impaired kidney functioning, the rate of elimination is reduced, which leads to the build-up of Zofran in the body. Any damage to the kidneys or in conditions like end-stage renal disease, the elimination of the drug will be slow and the drug remains in the system for a longer duration. 

Age

In elderly patients, the rate at which Zofran is eliminated from their system is 5.5 hours, which is slightly longer than in adults. This is primarily due to the natural decline in bodily functions that come with ageing, which can impact the way the drug is metabolized and excreted from the body. 

What happens if Zofran stays in the system for too long?

In preclinical and clinical trials, an overdose of ondansetron did not lead to any end-organ toxicity. In a clinical study, 36% of cancer patients who received doses of 1.5 mg/kg of Zofran experienced adverse effects like diarrhoea, headache, extra-pyramidal symptoms, and seizures. In the pediatric population receiving chemotherapy, the incidence of adverse reactions was 19%. (3)

One of the meta-analyses about the effects of ondansetron on pregnancy and fetus reported that Zofar was associated with incidents of cardiac abnormalities and defects in newborns. The study concluded that ondansetron should be used during pregnancy only if other medications are ineffective.

A case study reported an overdose of ondansetron in a 12-month-old infant who accidentally consumed eight tablets of 8mg ondansetron and developed seizures, hepatotoxicity, QTc prolongation and serotonin syndrome. The maximum pediatric dose of ondansetron is 16mg per dose and is calculated based on weight (0.15mg/kg/dose). (1)

Infants have a decreased clearance of ondansetron due to an underdeveloped CYP450 enzyme system, which is essential in the metabolism and excretion of the drug. (1)

What are the possible side effects associated with Zofran? 

Like all other drugs, Zofran is also associated with side effects such as: 

• Headaches
• Fatigue
• Dry mouth
• Malaise
• Constipation
• Drowsiness
• Sedation
• Local injection site reaction
• Pruritus
• Arrhythmias
• Impaired gut motility
• Stevens-Johnson syndrome

It is important to note that most of these symptoms are uncommon, and side effects caused by Zofran vary among individuals. If you notice any unwanted effects, consult your physician; your physician will either lower your dose or prescribe you another antiemetic drug. If you experience any severe rash or blisters after consuming Zofran, seek medical help immediately. Avoid alcohol when you are on Zofran, as it can increase the risk of side effects. 

In my experience

As far as I know, Zofran lasts for about 8 hours, and it is administered every 8-12 hours. However, there are certain factors which can influence the stay of Zofran in the system. If you are experiencing nausea and vomiting even after taking Zofran, make sure you consult your physician for a proper evaluation and assessment. Do not take a double dose of Zofran, as it may increase the risk of side effects. 

References