Body Surface Area-Based Dosing Flat- Fixed Dosing

Body Surface Area-Based Dosing Flat- Fixed Dosing vs. Body Surface Area-Based Dosing of Anticancer Drugs in Adults: Does It Make a Difference? Explain Body-Surface-Area-based dosage Body Surface Area-based dosing is a critical formula applicable in the calculation of drug doses in the case of two types of patient groups. These two types of patient groups include cancer patient under the aspect of chemotherapy and pediatric patients. DuBois and DuBois derived the formula in the case of 1916 in a research which nine individuals took part (DuBois & DuBois, 1916).

It is ideal to note that the average or normal adults have a BSA of about 1.73 m2. It refers to the current standard of care applicable in the determination of the dose of various chemotherapy drugs in relation to the body surface area of the patients on chemotherapy drugs. It is critical to understand that BSA-based dosing is a 'one size fits all' approach in relation to calculating drug dose with reference to patients on chemotherapy drugs.

The mathematical formula utilizes the height and weight of the patient in the calculation of the drug dose for chemotherapy and pediatric drugs. It is critical to note that BSA-based dosing approach is ineffective in addressing dosage issues for chemotherapy and pediatric drugs. According to various research studies, BSA-based dosing approach is ineffective in relation to realizing the optimal or right systematic concentration of the drugs with the aim of generating best treatment results (De Jongh et al., 2001).

Since its development in 1916, various research studies continue to illustrate how individuals absorb and process substances in the form of drugs and food into their systems. This is because of the number of factors influencing the rate of drug clearance. The rate of drug clearance varies from one person to another with approximately 30-fold difference. For instance, the functioning of an organ as well as the state of the disease will have massive impact on the body and its ability to process the chemotherapy drugs.

In addition, it is essential to note that more advanced cancer has the ability to absorb more drugs in comparison to the smaller tumor. Moreover, other factors in the form of age, genetics, sex, drug-drug interactions, and sleeping patterns might be crucial in causing variability from one person to another (Scripture & Figg, 2006). This makes BSA-based dosing ineffective towards the achievement of the goals and objectives.

How the formula is applied It is ideal to note that most of the pediatric dosages and oncologic dosages utilize the BSA-based dosing in relation to the calculation of the medication. This is an indication that the patient's body surface area is critical in arriving at the medication. In the calculation of the body surface area of an individual, the following formula is applicable: A= ? (W.H)/3600. In this case, A refers to the patient's body surface area (m2), W represents the weight of the patient in kg, while H.

represents the height of the patient in inches. Finally, 3600 represents the conversion or the correction factor thus kg/m3. In case the weight of the patient is in pounds (lbs) and the height is in inches, it is ideal to replace the 3600 (correction factor) with 3131. The formula relates to the initial DuBois and Dubois in the case of 1916 as follows BSA= 0.007184 X Height (m) 0.725 X Weight (kg) 0.425 before the transformation in 1987 by Mosteller. The BSA-based dosing is also applicable in the case of the calculation of the medication of children.

In the case o calculating the medication for children in using the formula, it is ideal to divide the child's body surface area by 1.73 before multiplying the result by the adult dose. For instance, in the case a physician prescribes Benadryl 150 mg/m2 for an 8-year-old child weighing 75 pounds and a height of about 4 feet 2 inches tall. Considering that the normal adult dose is about 25 mg q.i.d., it is critical to determine the how many mg of Benadryl for administration four times a day for the child.

In execution of this scenario, it is ideal to change the feet to inches. This is through multiplying 4 by 12 to generate 48 thus 50 inches following to the addition of the two inches. A= ? (W.H)/3131 A= ? (75 lb X 50 inches)/3131 = 1.09 m2 =1.09 m2 / 1.73 m2 = 0.63 X 25 mg = 15.75 mg It is critical to round off the value to the nearest whole number with the aim of generating an accurate value for the medication. Since 15.75 is closer to the whole number 16 in comparison to 15, it is ideal to round off the value to the nearest 16.

This is an indication that the dosage for the scenario is 16 mg q.i.d. Research where it came from Relatively narrow therapeutic window has been critical in illustrating the concept of Classic cytotoxic. This indicates that 'low' doses of the drugs might prove to be ineffective as well as very toxic in case 'high' doses. It is ideal to note that the optimal dose should be in between thus contributing to the best possible treatment.

The overall outcome of the best possible treatment should relate to maximal therapeutic effect in relation to manageable and tolerable toxicities. One of the critical assumptions in relation to dosing is that large patients with larger volume of distribution and greater metabolizing capacity need to be dosed higher in comparison to smaller patients with the aim of achieving adequate and equal drug concentrations. This led to the adoption and integration of the BSA (Body-Surface Area) with the aim of adjusting the traditional administration of doses.

During its initial development stage, BSA was calculated through the length and weight under the influence of DuBois and DuBois in the case of 1916 emanating from the investigation involving nine participants or individuals (DuBois & DuBois, 1916). Despite the lack of validation of the derived formula during the initial stages of its usage, the application of BSA was critical in the animal studies with the aim of achieving allometric scaling. As from 1950s, BSA-based dosing has been applicable in the case of pediatric oncology.

The essence of minimal further studies did not hinder utilization of the BSA-based dosing into drug dose calculation in the context of adults. Currently, BSA-based dosing is proving to the standard through which most agents use to calculate the dose for adults. Gehan and George (1970) focused in an experiment, which was critical to the development of BSA. This is because of the number of participants (400 individuals) in which the original formula was over-estimation of the real BSA by approximately 15%.

The research was also critical in under-estimating the concept of BSA in relation to a number of lower than one percent of the cases or participants. The findings were not crucial in the acceptance of the.