Do You Have to Take Mercaptopurine on an Empty Stomach? How Long After Taking the Medication Can You Drink Milk?

Source: Sunflower Children

Author: Linxia Sun

Editor: Zhengty

Date: December 19, 2024

Summary

Methotrexate: There is no need to drink excessive amounts of water, nor is there a need to specifically buy alkaline water; doctors will hydrate the child.

Mercaptopurine: Take the medication daily as prescribed by the doctor; there is no strict requirement to take it on an empty stomach before bed. Just ensure the prescribed dosage is taken that day.

Retinoic Acid: There is no need to deliberately avoid foods high in vitamin A and carotenoids; just be cautious about using high-dose vitamin A supplements unless advised by a doctor.

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Methotrexate

Methotrexate is a very important treatment medication, but it does have significant toxic side effects on the body. How can we reduce these side effects? By increasing water intake, we can help the medication exit the body more quickly through urine.

Thus, when doctors use methotrexate for children, they will implement hydration, which involves intravenous fluid administration that includes bicarbonate, a basic component. Meanwhile, they will monitor the child’s urine pH to keep it slightly alkaline, which facilitates the excretion of toxic substances. Therefore, parents do not need to make their children drink excessive amounts of water, nor do they need to specifically buy alkaline soda water for them.

Not only methotrexate but many chemotherapy drugs can have toxic side effects on the body. Drinking more water and urinating frequently can help. The dietary guidelines recommend a daily water intake that should be 1.5 to 2 times the usual amount during the entire chemotherapy period.

If the doctor has already provided intravenous hydration for the child, there is no need for excessive water intake, as children's stomach capacity is limited. During methotrexate treatment, if their appetite is poor, the limited stomach capacity should be used to consume nutritious food rather than to fill up on water.

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Mercaptopurine

Mercaptopurine is another commonly used medication in the treatment of childhood tumors, and it also causes significant concern for parents due to its complicated administration schedule.

Let's address the question first: Does mercaptopurine need to be taken on an empty stomach? Can it be taken while the child is breastfeeding?

The answer is no. This may come as a surprise, as many have heard that mercaptopurine must be taken on an empty stomach before bed, especially that one should avoid milk one hour before and two hours after taking the medication, as it could affect the drug's effectiveness in the body.

However, a new study published in 2017 found that whether the medication is taken on an empty stomach, at bedtime, or with milk does not significantly impact the treatment or recurrence of the disease. This study followed patients for six years and found that the biggest influencing factor was adherence, meaning whether the child took the prescribed dosage daily. In reality, children might not take the medication as prescribed due to the strict requirements, which can be more detrimental to treatment and prognosis. For instance, infants need to be fed every two to three hours, making it impossible to avoid feeding around medication times; some children on a nasogastric tube may constantly receive milk, making it challenging to maintain fasting periods.

Given these situations, we should focus on medication adherence—whether the child can consistently take the medication as directed.

The publication of this article caused quite a stir in the medical community, prompting a reevaluation of which recommendations for patients are essential and which can be reconsidered.

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Retinoic Acid

Parents often ask whether their child can eat foods containing vitamin A after starting retinoic acid. Some have gone to great lengths to compile lists of foods high in vitamin A, stating that these should be avoided while on retinoic acid. Unfortunately, this is incorrect.

Vitamin A is found in many foods, and restricting these can significantly affect a child's nutritional status and quality of life.

It’s important to note that retinoic acid and vitamin A are not the same thing. Retinoic acid is indeed a derivative of vitamin A, but it is not equivalent to vitamin A itself, nor to beta-carotene. We often say that eating carrots can supplement vitamin A, but what you actually consume is beta-carotene, which is then converted into vitamin A within the body.

Our bodies are quite intelligent; when you consume beta-carotene and there is plenty of vitamin A present, it converts less of it; when vitamin A is low, it converts more. Therefore, these vegetable sources, including carrots, pumpkins, and sweet potatoes, are fine and will not have any negative impact.

Vitamin A primarily comes from animal sources, such as liver. While taking retinoic acid, consuming too much may indeed cause toxic effects due to vitamin A excess, but having it once or twice a week or even monthly is generally acceptable.

Additionally, unless clearly advised by a doctor, do not supplement with high doses of vitamin A while on retinoic acid. For example, cod liver oil contains high doses of vitamins A and D. It is crucial to differentiate that cod liver oil is not the same as fish oil, which primarily consists of omega-3 unsaturated fatty acids.

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Finally, I want to stress the following points: First, throughout the treatment process, we will need to use many medications, so it’s vital to communicate with doctors, pharmacists, and clinical nutritionists about medication dosages, how to store the medications, how to administer them to children, potential side effects, and how to manage those side effects.

Second, follow medical advice; sometimes less is more. If a doctor recommends low-fat, it doesn’t mean you should go completely fat-free. If they say to reduce salt, it doesn’t mean you shouldn’t eat salt at all. Just follow your doctor's advice without unnecessary extremes.

Third, medicine is always evolving, with ongoing clinical research bringing us closer to the truth. Many previous standard practices have put significant burdens on parents and children, and some may not be as crucial as once thought. Continuous clinical research is validating this, allowing us to focus our energy on more important matters in the future.

Wishing all children a smooth treatment and a speedy recovery!

Course Instructor: Linxia Sun

Former Clinical Dietitian at Johns Hopkins University

Content Organized by: Xia Yu

Edited by: Zuo Jia

Formatted by: Yi Meng

Proofread by: A Dou Dou