The nurse is reviewing medication prescriptions.
Which is an appropriate dosage and frequency of cimetidine?

800 mg PO at bedtime is an appropriate dosage and frequency of cimetidine for the treatment of gastric ulcer. Cimetidine is a histamine H antagonist that reduces the secretion of gastric acid.

Choice B is wrong because 150 mg PO b.i.d. is too low of a dose for cimetidine. The usual adult dose for duodenal ulcer is 800 mg PO once a day at bedtime or 300 mg PO four times a day.

Choice C is wrong because 20 mg PO b.i.d. is not a valid dose for cimetidine.

The lowest available tablet strength is 100 mg.

Choice D is wrong because 300 mg PO at bedtime is also too low of a dose for cimetidine.

The usual adult dose for gastric ulcer is 800 mg PO once a day at bedtime or 300 mg PO four times a day.

Guaifenesin is an expectorant that helps thin and loosen mucus in the lungs, making it easier to cough up the sputum. Some possible explanations for the other choices are:

Choice A. Benzonatate is wrong because benzonatate is an antitussive that suppresses the cough reflex by numbing the throat and lungs.

It does not help with sputum production or clearance.

Choice B. Dextromethorphan is wrong because dextromethorphan is also an antitussive that acts on the brain to reduce the urge to cough.

It does not affect the mucus or bronchial secretions.

Choice C. Hydrocodone is wrong because hydrocodone is a narcotic antitussive that works by binding to opioid receptors in the brain and spinal cord, blocking pain signals and decreasing cough.

It can cause sedation, respiratory depression, and dependence, and is not indicated for bronchitis.

Normal ranges for sputum production vary depending on the individual and the cause of the cough, but generally range from 10 to 100 mL per day.

Excessive or abnormal sputum may indicate an infection, inflammation, or obstruction of the airways.