Question

Read the medication labels where available, and calculate the number of tablets or capsules necessary to provide the dosage ordered. Include the label on your answer. Order: Lopressor \(100 \mathrm{mg}\) p.o. b.i.d. Available: Lopressor tablets labeled \(50 \mathrm{mg}\)______.

Short answer

You need 2 tablets per dose and 4 tablets per day.

Step-by-step solution

Understanding the Order

The order is for Lopressor at a dosage of 100 mg to be taken twice a day (b.i.d. stands for 'bis in die,' which means twice a day). This means the patient needs to take 100 mg in the morning and 100 mg in the evening.

Identifying What is Available

The available Lopressor is in tablet form, each labeled as 50 mg. This means each tablet contains 50 mg of the active ingredient.

Calculating Tablets per Dose

Since each tablet is 50 mg and you need a 100 mg dose, divide the required dose by the tablet strength to determine how many tablets are needed per dose: \[ \frac{100 \text{ mg}}{50 \text{ mg/tablet}} = 2 \text{ tablets} \]Thus, you need 2 tablets to make up one dose of 100 mg.

Calculating Total Tablets for the Day

Since the order requires the medication to be taken twice a day, multiply the number of tablets per dose by the number of doses per day:\[ 2 \text{ tablets/dose} \times 2 \text{ doses/day} = 4 \text{ tablets/day} \]Therefore, you will administer a total of 4 tablets per day.

Key concepts

Tablet Calculations

Tablet calculations are a fundamental aspect of pharmaceutical mathematics. It involves determining the number of tablets a patient needs to take to meet a prescribed medication dosage. When performing tablet calculations, several factors must be taken into account:

• Dosage Ordered: This is the amount of medication the doctor wants the patient to receive. In the case of Lopressor, it's 100 mg per dose.
• Tablet Strength Available: This refers to the strength of each individual tablet that you have. For example, if your tablets are 50 mg each, like the Lopressor tablets in this example, this influences how many you need to meet the doctor's order.

For this problem, you need to calculate how many 50 mg tablets are required to make up the 100 mg dosage ordered by the doctor. You do this by dividing the required dose (100 mg) by the available tablet strength (50 mg/tablet), resulting in two tablets per dose. Hence, when a dosage requires a larger active ingredient concentration than a single tablet provides, additional tablets must be taken.

Dosage Interpretation

Dosage interpretation is crucial for ensuring the patient's safety and achieving the desired therapeutic effect. Understanding how to read and interpret a medication order is a key skill.

• Order Details: Recognize that 'p.o.' means by mouth, and 'b.i.d.' means twice a day. These instructions dictate how frequently and by which route the medication should be administered.
• Frequency Analysis: When the dosage says b.i.d., it's important to understand that the entire daily dosage must be divided accordingly, yet each dose should independently meet the prescribed amount.

In this scenario, the prescription indicates that a patient takes 100 mg twice per day. Proper dosage interpretation ensures the patient receives the correct amount at the right times, preventing underdosing or overdosing.

Pharmaceutical Mathematics

Pharmaceutical mathematics is pivotal in healthcare for ensuring drug safety and efficacy. It involves using mathematical techniques to calculate medication doses, which is vital for pharmacists, nurses, and doctors.

• Unit Conversion: Basic comprehension of units and converting them, when needed, is key. Although this was not needed in our Lopressor example, it's a common necessity in pharmaceutical settings.
• Calculation Techniques: Methods such as division, multiplication, and ratio proportion are frequently used. Our Lopressor exercise required simple division to determine the number of tablets needed.

Drug calculations are not just about numbers; they're about understanding how and why the math applies to medication administration. With precise pharmaceutical mathematics, healthcare professionals can assure that patients receive correct and safe amounts of their medications.