As the use of weight-based dosing becomes more common in medication, there may be confusion about how it works and what exactly to do with this information. This article is intended to provide an overview of what weight-based dosing is, how it works with medication, and why physicians are increasingly likely to use the method.

How does weight based medication dosing work?

Weight-based medicine doses are prescribed for children and adults with conditions where there is a wide range of optimal dosages. The most common examples are antibiotics, opioids, diabetes medications, and chemotherapy drugs. Typically, these patients will be started out on small doses that are increased until the recommended dosage is reached (the maximal allowable dose). This can cause confusion when parents come in asking about how many pills they should give their child. If the parent only has one bottle of medication, then prescribing more than is needed can lead to an overdose, whereas labeling every pill as the same size is misleading when each pill may contain a significantly different dosage. They can use digital scales to dispense medication in a more precise manner. This is already used in the hospital setting to individualize dosages for critically ill patients. Also, medications often have interactions with each other, so the combinations are sometimes used to find out how much of one drug is needed to reduce the side effects of another.

Why are physicians increasingly likely to use weight-based doses?

There are multiple reasons for this trend. One reason physicians may be more likely to use weight-based medication dosing is that the Food and Drug Administration has been making more drugs available with approval for both adults and children. Children are being given less time on drug trials, so there are far fewer studies done specifically on pediatric populations. Clinical trials typically require participants to have similar conditions, so if a new drug only needs to be tested on diabetes patients, but it works differently in adults versus kids, then additional studies need to be conducted before it can be used for all age groups. Another reason physicians may choose weight-based doses is that the older methods of calculating dosage assumed that all people had the same reaction levels to medication. Overdose was fairly common because this method made it impossible to account for how individuals metabolize the medication.

Why are more people using this now?

With an increase in adult use, older drugs are being reformulated for both children and adults. This means that physicians who want access to the newest medication are more likely to use weight based dosing as a way to communicate with their patients. Patients are also less willing to let their children suffer through pain when there is an option available that can relieve or even eliminate discomfort without causing additional side effects, which may be worse than the original disease.  Weight-based dosing allows patients to have increased control over their own health because it gives them a greater say in what size doses they need versus what size pills they are given. This is particularly important for pediatric patients because their dosage needs can change as their bodies grow (which means that the standard adult dose may end up being too high or too low, even though it was correct when the drug was first created).

What can patients do to learn more about their weight-based dosage calculation?

A patient can ask their doctor about what type of weight-based dosing method they are using before a new prescription is written. If a patient wants to avoid confusion with previously written prescriptions then it is critical that they write down any information that can help them calculate the dosage when it comes in, such as the number of milligrams in each pill and how many pills there are per bottle (if there is more than one). A pharmacist may be able to help patients who require assistance interpreting their medication dosage.

How can weight-based dosing methods affect a patient’s ability to take medications correctly?

This can vary depending on the specific medication and how it is being consumed. If a patient is using a liquid medication, for example, they should ask how much fluid this needs to be diluted with before it can be safely consumed. There are medications that require people to weigh themselves every day and take the exact same amount of drugs on a daily basis. In other cases, weight-based dosing helps ensure that patients will receive additional pain relief if necessary even after the time interval indicated by their original prescription has passed.

Does insurance cover this weight-based dosage?

This depends on which type of health care coverage a person has. Medicare requires all drugs under their plan to be individually budgeted by the pharmaceutical company, so they never use weight-based doses for any patient population. For private health care plans to cover weight-based doses, they must have been given pre-approval by the plan. This is not uncommon because most plans that use this method will work with local pharmacies to ensure that all claims for prescription drugs are considered fairly. The pharmacy benefits manager (or PBM) is responsible for ensuring compliance with all rules and regulations related to how medications are administered.

What other issues do patients need to be aware of when taking weight-based doses?

Weight-based dosing was created as a way to increase patients’ self-determination over their own health care decisions. However, even if patients have been able to calculate what dosage size they need, it’s still important for them to remain active in their recovery. It is a good idea for patients to use tools such as pillboxes so that they can keep track of whether they have been taking their medications correctly. This way, if there are any issues with the dosage that needs to be addressed like an unintentionally missed dose or confusion over the number of times the medication has been taken, then patients and their physician can work together to find a solution without wasting valuable time and money on unnecessary treatments.

Weight-based dosing helps patients gain a more active role in their own health care, but there are still things that they will need to do themselves to ensure the success of their recovery. We hope that this guide was helpful and that patients can use it to determine whether they are ready for this treatment method.