What electrolyte inactivates troponin and allows actin and myosin to form a bridge enabling fibers to contract?

Choice A rationale

Coagulation studies assess the blood's ability to clot and are not directly related to the monitoring of phenytoin therapy. These tests are more relevant for patients with bleeding disorders or those on anticoagulant therapy.

Choice B rationale

Serum electrolytes, including levels of sodium, potassium, and calcium, are important for overall health but are not specifically indicative of phenytoin levels. Phenytoin may affect calcium metabolism, but it is not the primary focus for routine monitoring.

Choice C rationale

Renal function tests are crucial for assessing kidney function but do not directly monitor phenytoin therapy. Phenytoin is primarily metabolized in the liver, making liver function tests more relevant.

Choice D rationale

Blood glucose levels should be monitored in patients taking phenytoin as the drug can cause alterations in blood glucose levels. Both hypoglycemia and hyperglycemia have been reported, so it is important to check glucose levels to ensure they remain within a normal range.

Choice A rationale

Administering amoxicillin when a patient has a known allergy to penicillin can result in a serious allergic reaction. It is important to avoid using any beta-lactam antibiotic in patients with a history of penicillin allergy.

Choice B rationale

Contacting the provider to discuss using a different antibiotic is the safest course of action. The provider can prescribe an alternative antibiotic that does not belong to the beta-lactam class, reducing the risk of an allergic reaction.

Choice C rationale

Asking the provider to order an antihistamine does not address the underlying risk of administering a beta-lactam antibiotic to a patient with a penicillin allergy. Antihistamines are used to manage allergic reactions, not to prevent them.

Choice D rationale

Requesting an order for a beta-lactamase resistant drug does not eliminate the risk of an allergic reaction, as these drugs still belong to the beta-lactam class and can trigger the same allergic responses in sensitive individuals.