A physician ordered 52.5 mg every 6 hours. The Demerol label reads 20mg in 2 milliliters. What will the patient receive in a single dose

The ordered amount is, as it sounds, the amount of medication prescribed by a physician or healthcare provider with the prescription of medications listed as within their scope of practice. The order should also include the route of administration, usually depending on the form of medication; some are introduced intravenously (IV) while other may be taken orally (PO).

The dosage strength is what is available within a facility's pharmacy, usually represented by a fraction with different units of measurement in the numerator and denominator known as a conversion factor, and determined by reading the prescription label on the container holding the medication.

In the question, the ordered amount is the 52.5 mg that is to be administered every 6 hours (in healthcare facilities, they may be seen as q6h). The dosage strength is 20 mg per 2 mL; this can be simplified to 10 mg per 1 mL or 10 mg/mL. This simply means, there are 10 milligrams of medication per 1 milliliter of volume.

Now, plug this information into the formula and solve for the dosage amount.

dosage amount = 52.5 mg x mL/10 mg
= 52.5 mg mL / 10 mg

Milligrams (mg) in numerator and denominator cancel

= 52.5 mL / 10
= 5.25 mL

The patient will receive 5.25 mL of opioid analgesic meperidine (brand name Demerol) in a single dose every 6 hours.