A client is prescribed a drug as 0.3 mcg, q4h. Calculate the dose of the medicine per day.

To answer this question, we need to understand the principles of pediatric dosage calculations and the factors that affect them. Pediatric dosages are usually calculated based on the child's weight or body surface area, and sometimes adjusted for age, organ function, or disease severity¹. However, not all medications that are used in adults are safe or effective in children. Some medications may have different pharmacokinetics, pharmacodynamics, adverse effects, or interactions in children than in adults².

Therefore, it is important to check the drug insert or label for any contraindications, warnings, or precautions for pediatric use before prescribing or administering a medication to a child. If the drug insert states that the medication is not for pediatric use, it means that the medication has not been tested or approved for use in children, or that it has been shown to be harmful or ineffective in children. In this case, a pediatric dose calculated from an adult dose should be avoided, as it may result in serious toxicity or therapeutic failure. The healthcare provider should consult a pediatric specialist, a pharmacist, or a reliable drug reference for alternative medications or dosing recommendations.

The other options are not correct because they do not necessarily warrant avoiding a pediatric dose calculated from an adult dose.

Option a. If the drug insert does not specify a pediatric dose, it means that there is insufficient data or evidence to support a specific pediatric dose, but it does not mean that the medication is contraindicated or unsafe in children. The healthcare provider should use clinical judgment and available resources to determine the appropriate dose for the child³.

Option b. If the child has an elevated temperature that has not responded to treatment, it means that the child may have an infection or inflammation that may affect the absorption, distribution, metabolism, or excretion of some medications. The healthcare provider should monitor the child's condition and adjust the dose accordingly, but it does not mean that the medication should be avoided altogether⁴.

Option c. If the child has gained or lost weight in the past month, it means that the child's weight may have changed significantly since the last dose calculation. The healthcare provider should weigh the child and recalculate the dose based on the current weight, but it does not mean that the medication should be avoided altogether.

To find the total amount of heparin, you need to calculate the following:

- The concentration of heparin in units per milliliter
- The volume of heparin infused from 9:00 am to 11:00 am and from 11:00 am to 2:00 pm
- The amount of heparin in units from each time period and the total amount

First, divide the amount of heparin by the volume of D5W to get the concentration in units per milliliter:

25,000 units / 250 mL = 100 units/mL

Next, multiply the infusion rate by the duration to get the volume infused in each time period:

From 9:00 am to 11:00 am (2 hours), the infusion rate is 12 mL/hr:

12 mL/hr x 2 hours = 24 mL

From 11:00 am to 2:00 pm (3 hours), the infusion rate is 10 mL/hr:

10 mL/hr x 3 hours = 30 mL

Then, multiply the volume infused by the concentration to get the amount of heparin in units in each time period:

From 9:00 am to 11:00 am, the volume infused is 24 mL:

24 mL x 100 units/mL = 2400 units

From 11:00 am to 2:00 pm, the volume infused is 30 mL:

30 mL x 100 units/mL = 3000 units

Finally, add the amounts of heparin from each time period to get the total amount:

2400 units + 3000 units = 5400 units

Therefore, the patient received **5400 units** of heparin from 9:00 am to 2:00 pm.