To determine the correct dose of a particular drug for a patient, we consider the patient’s sex, weight, age, and physical condition, as well as the other drugs that the patient is taking.
Frequently, the dose that is needed for a patient is not the dose that is available, and it is necessary to convert the dose form available into the prescribed dose. Doing the necessary mathematical calculations to determine what should be given is the responsibility of the prescriber who orders the drug, the pharmacist who dispenses the drug, and the nurse who administers the drug. This allows the necessary checks on the dose being given before the patient actually receives the drug. Another check to help prevent medication errors is that in many institutions, drugs arrive at the patient care area in unit-dose form, prepackaged for each individual patient.
The nurse who will administer the drug may come to rely on this prepackaged system, forgoing any recalculation or rechecking of the dose to match the written order. Unfortunately, mistakes still happen, and the nurse, as the person who is administering the drug, is legally and professionally responsible for any error that might occur. Practicing nurses must know how to convert drug dosing orders into appropriate doses of available forms of a drug to ensure that the right patient is getting the right dose of a drug.