A 79-year-old patient is receiving a quinolone for treatment of a complicated incision infection.
For which adverse effect associated with these drugs should the nurse monitor?

Choice A rationale:

Constipation is not typically associated with hyperthyroidism. In fact, one of the symptoms of hyperthyroidism is increased bowel movement. This is due to the increased metabolic rate caused by the overproduction of hormones from the thyroid gland.

Choice B rationale:

Weight gain is not a common symptom of hyperthyroidism. On the contrary, weight loss is one of the symptoms of this condition. This is because hyperthyroidism speeds up the body’s metabolism, causing increased calorie burning and significant weight loss. Choice C rationale:

Sensitivity to cold is not a symptom of hyperthyroidism. Instead, individuals with hyperthyroidism often have an increased sensitivity to heat. This is due to the increased metabolic rate which can cause excessive sweating and hot flashes.

Choice D rationale:

Frequent mood changes are a common symptom of hyperthyroidism. The overproduction of hormones by the thyroid gland can lead to symptoms such as irritability and restlessness. Additionally, other symptoms such as difficulty sleeping can also contribute to mood changes.

Choice A rationale:

Phenytoin is an anticonvulsant drug used in the prophylaxis and control of various types of seizures. It has a narrow therapeutic index, which means that the safe and toxic plasma levels of the drug are very close to each other. This characteristic makes the dosing of phenytoin challenging, as even small deviations from the recommended therapeutic range can lead to suboptimal treatment or adverse effects. Therapeutic effect without clinical signs of toxicity occurs more often with serum total concentrations between 10 and 20 mcg/mL34. Therefore, clinicians are advised to initiate therapeutic drug monitoring in patients who require phenytoin.

Choice B rationale:

The statement that phenytoin has a low chance of being effective is incorrect. Phenytoin is a widely used and effective anticonvulsant. It works by slowing down impulses in the brain that cause seizures. It is used to control seizures but does not treat all types of seizures. The effectiveness of phenytoin is not determined by its narrow therapeutic index but by its pharmacological action in the brain.

Choice C rationale:

The assertion that there is no difference between safe and toxic plasma levels of phenytoin is incorrect. There is indeed a difference between the safe (therapeutic) and toxic levels of phenytoin. The therapeutic range for phenytoin is typically between 10 and 20 mcg/mL34. Levels above this range can lead to toxicity, while levels below this range may not provide the desired therapeutic effect.

Choice D rationale:

The statement that a very small dosage of phenytoin can result in the desired therapeutic effect is not entirely accurate. While it’s true that phenytoin is effective in controlling seizures, the dosage required to achieve this effect is not necessarily “very small”. The usual adult dose for seizures is 100 mg orally 3 times a day. The dosage may need to be adjusted based on individual patient factors and response to therapy. Therefore, it’s not accurate to generalize that a “very small” dosage will result in the desired therapeutic effect for all patients.