The healthcare provider prescribes cyanocobalamin injection 100 mcg IM every 3 days for a client with pernicious anemia. The vial is labeled, “1 mg/mL.” How many mL should the nurse administer? (Enter numerical value only. If rounding is required, round to the nearest tenth.)
The Correct answer and Explanation is:
To determine how many mL of cyanocobalamin the nurse should administer, we start by converting the prescribed dose of 100 mcg to mg, as the vial’s concentration is given in mg/mL.
- Convert micrograms to milligrams:
[
100 \, \text{mcg} = 0.1 \, \text{mg}
] - Determine the concentration of the medication:
The vial is labeled as 1 mg/mL. This means that for every 1 mL of the solution, there is 1 mg of cyanocobalamin. - Calculate the volume to administer:
To find out how many mL of the solution is needed to get 0.1 mg, we use the following formula:
[
\text{Volume (mL)} = \frac{\text{Desired Dose (mg)}}{\text{Concentration (mg/mL)}}
]
Plugging in the values:
[
\text{Volume (mL)} = \frac{0.1 \, \text{mg}}{1 \, \text{mg/mL}} = 0.1 \, \text{mL}
]
Therefore, the nurse should administer 0.1 mL of cyanocobalamin.
Explanation:
Cyanocobalamin is a form of vitamin B12 used to treat pernicious anemia, a condition characterized by the body’s inability to absorb vitamin B12 due to a lack of intrinsic factor. The administration of vitamin B12 via injection is often necessary for patients with this condition, as oral supplements may not be adequately absorbed.
In calculating medication dosages, it is crucial to understand the units of measurement involved. In this case, converting micrograms to milligrams was necessary because the concentration of the vial was given in milligrams per mL.
Ensuring accurate dosage is critical in nursing practice to avoid under-dosing or overdosing patients. Using a systematic approach to dosage calculations helps nurses provide safe and effective care. In this instance, administering the correct volume ensures that the patient receives the appropriate amount of medication, contributing to effective treatment for pernicious anemia. Proper rounding to the nearest tenth is also a standard practice in medication administration to maintain accuracy and safety in patient care.