When monitoring patients on antitubercular drug therapy, the nurse knows that which drug may cause a decrease in visual acuity?

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:

Double vision is not a common side effect of quinolones. Quinolones are a type of antibiotic that are used to kill or inhibit the growth of bacteria. While they can have side effects, double vision is not typically one of them.

Choice B rationale:

Tendonitis and tendon rupture are known adverse effects of quinolones. These antibiotics can very rarely cause long-lasting, disabling, and potentially irreversible side effects, sometimes affecting multiple systems, organ classes, and senses. One of these side effects is damage to the tendons, which can manifest as tendonitis (inflammation of the tendon) or even tendon rupture. This is particularly a concern for people older than 60 years and for those with renal impairment or solid-organ transplants because they are at a higher risk of tendon injury.

Choice C rationale:

Neuralgia, or nerve pain, is not a common side effect of quinolones. While these antibiotics can affect the nervous system and cause side effects such as peripheral neuropathy and central nervous system effects, neuralgia is not typically reported.

Choice D rationale:

Hypotension, or low blood pressure, is not typically associated with the use of quinolones. These antibiotics can have various side effects, but a significant drop in blood pressure is not commonly reported.