A nurse is preparing to administer hydromorphone 2.5 mg. The available amount is 5 mg/5 mL elixir.

How many mL should the nurse administer?

The question is about calculating the volume of phenytoin oral solution that the nurse should administer per dose. The client is prescribed 250 mg of phenytoin and the available solution has a concentration of 25 mg/5 mL.

Let’s calculate the volume step by step:

Step 1: Identify the prescribed dose and the concentration of the available medication. The prescribed dose is 250 mg and the concentration of the available medication is 25 mg/5 mL.

Step 2: Set up the calculation. We want to find out how many mL correspond to the prescribed dose. We can set up the calculation as follows: (Prescribed dose ÷ Concentration) × Volume.

Step 3: Substitute the known values into the calculation. This gives us: (250 mg ÷ 25 mg/5 mL).

Step 4: Perform the division operation first due to the order of operations (BIDMAS/BODMAS). This gives us: (250 mg ÷ 5 mg/mL).

Step 5: Perform the final calculation. This gives us: 50 mL.

So, the nurse should administer 50 mL of the phenytoin oral solution per dose.

Please note that this calculation assumes that the prescribed dose (250 mg) is to be administered in one go. If the dose is to be split over the day, the volume to be administered would change accordingly.

Choice A rationale:

Erythromycin Erythromycin is a macrolide antibiotic that is often used as an alternative to penicillin. It is generally safe for use in patients with a penicillin allergy. It works by inhibiting bacterial protein synthesis and is effective against a wide range of bacteria.

Choice B rationale:

Amphotericin B Amphotericin B is an antifungal medication, not an antibiotic. It is used to treat serious, systemic fungal infections. It has no cross-reactivity with penicillin, so it would not be a concern for a patient with a penicillin allergy.

Choice C rationale:

Amoxicillin-clavulanate Amoxicillin-clavulanate is a type of penicillin antibiotic. Patients with a known penicillin allergy should avoid this medication, as they may have a cross-reactivity to it. This is why the nurse should verify this prescription with the provider.

Choice D rationale:

Gentamicin Gentamicin is an aminoglycoside antibiotic used to treat serious bacterial infections caused by gram-negative bacteria. It is not related to penicillin and would be safe for a patient with a penicillin allergy.