b. This is a second-generation antihistamine that does not cause drowsiness. Clients who are driving or operating machinery can safely take this medication.

a. Guaifenesin is indicated for nonproductive coughs. The nurse should reassess the client to determine if the cough is productive and an alternative medication should be considered.

c. Acetylcysteine is also indicated for clients suffering from acetaminophen toxicity.

c. Oxymetazoline should not be used for more than 3 days because of the chance of rebound congestion.

d. Opioid antitussives inhibit coughing by exerting their effects on the central nervous system. This increases the client’s risk of respiratory depression.

a. Grapefruit juice should be avoided when taking dextromethorphan because it can increase its action.

c. Constricting blood vessels in the nose decreases the amount of fluid draining from the blood vessels into the nasal passage.

c. It works by blocking histamine responses at H1 receptors.

c. $\frac{50\mathrm{m}\mathrm{g}}{x\mathrm{m}\mathrm{L}}$ (desired dose) $=\frac{25\mathrm{m}\mathrm{g}}{1\mathrm{m}\mathrm{L}}$ (supply on hand)

b. $\frac{10\mathrm{m}\mathrm{g}}{x\mathrm{t}\mathrm{a}\mathrm{b}\mathrm{l}\mathrm{e}\mathrm{t}\mathrm{s}}$ (desired dose) $=\frac{5\mathrm{m}\mathrm{g}}{1\mathrm{t}\mathrm{a}\mathrm{b}\mathrm{l}\mathrm{e}\mathrm{t}}$ (supply on hand)