A patient weighing 120 pounds was administered 2.1 g of a drug supposed to be dosed at 30 mg/kg. Was the dose correct, an overdose, or an underdose?
The correct answer and explanation is :
The correct dose for a 120-pound (≈54.43 kg) patient at 30 mg/kg is 1,632.93 mg. The patient received 2,100 mg (2.1 g), which is an overdose of approximately 467.07 mg.
Explanation (300 words):
In medicine, accurate dosing is essential to ensure both efficacy and safety. Many medications are prescribed based on a patient’s weight, especially in pediatrics and cases involving potent drugs. In this scenario, we’re given a patient who weighs 120 pounds and was administered 2.1 grams (or 2,100 milligrams) of a medication. The proper dosing guideline is 30 milligrams per kilogram of body weight.
To calculate the correct dose, we first convert the patient’s weight from pounds to kilograms. Since 1 kilogram equals approximately 2.20462 pounds, 120 pounds is equal to about 54.43 kilograms. Applying the dosing formula (30 mg/kg), we multiply 54.43 kg by 30 mg, resulting in a recommended dose of approximately 1,632.93 milligrams.
However, the patient received 2.1 grams, which is equal to 2,100 milligrams. This is 467.07 milligrams more than the appropriate dose. While the significance of this overdose depends on the drug’s safety margin and toxicity threshold, an overdose of this size (about 28.6% more than the recommended dose) could lead to adverse effects, particularly with drugs that have narrow therapeutic windows.
This situation underscores the importance of double-checking conversions and calculations in clinical settings. A small mistake in unit conversion or misunderstanding of weight-based dosing can have serious consequences. Healthcare professionals must be diligent when interpreting prescription instructions and calculating dosages, especially when converting between measurement systems (pounds to kilograms or grams to milligrams).
In conclusion, the patient received an overdose of the medication. The correct course would be to monitor the patient for any adverse effects and review protocols to prevent future errors.