There are a number of factors that could affect the correct pediatric dosage of a medication, although the factors most commonly used in calculations are age and weight. Weight is usually especially important, because it can greatly affect the amount of a drug required to have the desired effect. Other factors that could affect dosages for children include the gender of the child, race and whether the drug is to be taken before or after meals.
Being able to calculate pediatric dosage correctly is essential for anyone prescribing or administering medication to children. A dosage that’s too low may not have the desired effect, while too much of a particular drug can cause unwanted side effects or even death. The two most important factors affecting dosage are weight and age, although there are many others that may need to be taken into consideration.
Weight is usually the factor that has the most effect on the correct dosage. To calculate a child’s dosage, the weight of the child is usually divided by the average adult weight to form a ratio. The adult dosage, which is commonly calculated for a 24-year-old adult, is then multiplied by this ratio to calculate the correct child’s dosage. This method for calculating the dosage is known as Clark’s Rule.
Age is another important factor when calculating a pediatric dosage. In most cases, the younger a child is, the less medication he or she needs to take to produce the desire effect. Calculating a pediatric dosage using a child’s age is similar to the calculation for weight, except the dosage ratio is found by dividing the age of the child by that age plus 12 years. This ratio is then multiplied with the adult dosage to calculate the correct child’s dosage.
Although age and weight are the most commonly used factors when calculating a pediatric dosage, others may have an effect. Females, for example, often require smaller doses than males. The genetic makeup of the child also may affect how he or she reacts to a particular drug, so this may need to be taken into account. Other potential factors include race, the time of day a medication is given and how frequently the drug needs to be taken. The various factors make it essential for a doctor or pharmacist to calculate pediatric dosage, because such professionals are trained to understand the different factors involved.