A nurse is preparing to administer phenobarbital 3 mg/kg/day PO in two divided doses to a client who weighs 145 lb. The amount available is phenobarbital 100 mg/tablet. How many tablets should the nurse administer per dose? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)

A. Tinnitus. Nitrofurantoin is not commonly associated with ototoxicity or tinnitus. Medications such as aminoglycosides and loop diuretics are more likely to cause this adverse effect. While nitrofurantoin can have some neurological side effects, tinnitus is not a primary concern.

B. Abdominal cramping. Gastrointestinal side effects such as nausea and vomiting can occur with nitrofurantoin, especially if taken on an empty stomach. However, abdominal cramping is usually mild and not a serious adverse effect requiring discontinuation of the medication. Taking the drug with food can help reduce gastrointestinal discomfort.

C. Stevens-Johnson syndrome. Stevens-Johnson syndrome (SJS) is a rare but serious hypersensitivity reaction that can occur with nitrofurantoin use. It presents with flu-like symptoms, followed by a painful rash, blistering, and skin peeling. Immediate discontinuation and medical intervention are required if symptoms develop, as SJS can be life-threatening.

D. Insomnia. Nitrofurantoin does not commonly cause insomnia. Some medications, such as corticosteroids and stimulants, are more likely to interfere with sleep. Nitrofurantoin’s side effects primarily affect the gastrointestinal, pulmonary, and dermatologic systems rather than sleep patterns.

A. Deferoxamine. Deferoxamine is a chelating agent used to treat iron overload or toxicity. It has no role in managing an acute allergic reaction or respiratory distress caused by nafcillin, a penicillin-type antibiotic.

B. Vitamin K. Vitamin K is used to reverse the effects of warfarin-induced anticoagulation and is not indicated for treating an allergic reaction. Anaphylaxis is not related to coagulation disturbances, making this an inappropriate intervention.

C. Epinephrine. Epinephrine is the first-line treatment for anaphylaxis, which can present with difficulty breathing, bronchospasm, and hypotension. It works by stimulating alpha- and beta-adrenergic receptors, leading to bronchodilation, increased cardiac output, and vasoconstriction to counteract severe allergic reactions. Immediate administration is necessary to prevent further airway compromise and circulatory collapse.

D. Prednisone. Prednisone is a corticosteroid used to reduce inflammation and prevent delayed allergic reactions. While it may be prescribed as part of long-term management, it does not provide the rapid bronchodilation and vasoconstriction needed for emergency treatment of anaphylaxis.