Dosages of oral medications

2 Dosages of oral medications

Drugs may be administered via several routes, including by injection, by intravenous infusion, or orally. The first medications that a student nurse will administer to patients are usually oral medications.

Skills covered in this chapter include:

• calculating the actual dose required for an oral medication based on the prescription

• identifying the best combination of tablets required for specific prescriptions, so as few tablets as possible are used

• calculating the amount of liquid medication in a specific volume

• interpreting the information on medication labels to accurately calculate dosages.

What you need to know

Oral dosages may be in the form of tablets or capsules or in liquid form.

A whole tablet is always preferable to a broken tablet because, unless a tablet is broken accurately, the dose will not be exact. If it is necessary to break a tablet or capsule, check the manufacturer’s guidelines or check with the pharmacist to ensure it is acceptable to do so, as some should never be broken.

Many oral medications are available in liquid form. The liquid may be a syrup, an elixir, a solution or a suspension.

Important: Suspensions must be shaken thoroughly before measuring the required volume.

Check that stock strength and the strength required are given in the same unit in a particular calculation (i.e. both strengths in grams or milligrams or micrograms).

Important: If in any doubt about the answer to a calculation, then ask a supervisor to check your calculation.

Refer to Inside front cover page for explanations of abbreviations.

Calculating dosages of tablets

Exercise 2A

1 A patient is prescribed paracetamol 1 g, orally. The stock available is 500 mg tablets. Calculate the number of tablets required.

2 Prescribed: codeine 15 mg, PO. Stock on hand: codeine 30 mg tablets. How many tablets should be administered to the patient?

3 A patient is prescribed furosemide (frusemide) 60 mg, orally. In the ward are 40 mg tablets. How many tablets should be given?

4 How many 30 mg tablets of codeine are needed for a dose of 0.06 gram?

5 750 mg of ciprofloxacin is required. The available tablets are of strength 500 mg. How many tablets should be given?

6 A patient is prescribed 150 mg of soluble aspirin. On hand are 300 mg tablets. What number should be given?

7 450 mg of soluble aspirin is prescribed. Stock available is 300 mg tablets. How many tablets should the patient receive?

8 25 mg captopril PO is prescribed. How many 50 mg tablets should be given?

9 The stock available in the unit is diazepam 5 mg tablets. How many tablets are to be administered if the prescription is diazepam 12.5 mg?

10 Digoxin 125 micrograms is prescribed. Tablets available are 0.25 mg. How many tablets should be given?

Check that you have used the same unit of weight throughout a calculation.

Are both weights in grams (g)?

or are both weights in milligrams (mg)?

or are both weights in micrograms?

Check your answers on page 146.

Combinations of tablets

For some medications, tablets are available in different strengths. The tablets may be colour-coded to reduce the risk of error when dispensing.

Note: The least number of tablets is the best combination to be given to the patient.

Tags: Nursing Calculations

Dec 3, 2016 | Posted by admin in NURSING | Comments Off

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