Pharmacy Practice Flashcards

A patient is prescribed lithium for bipolar disorder. Which condition increases the risk of lithium toxicity?

Answer: Dehydration

Dehydration reduces renal lithium clearance, causing accumulation and toxicity since lithium is renally excreted without protein binding.

Which schedule of controlled substances has the HIGHEST accepted medical use but LOWEST potential for abuse?

Answer: Schedule V

Schedule V substances (e.g., cough preparations with <200 mg codeine per 100 mL) have low abuse potential and accepted medical uses.

A pharmacist checks a new prescription for ciprofloxacin and notes the patient is also taking sucralfate. What interaction should be addressed?

Answer: Sucralfate chelates ciprofloxacin, reducing its absorption

Sucralfate forms insoluble chelates with ciprofloxacin, significantly reducing its oral bioavailability by up to 90%.

What is the maximum daily acetaminophen dose recommended for a healthy adult to avoid hepatotoxicity?

Answer: 4,000 mg

The FDA-recommended maximum acetaminophen dose for healthy adults is 4,000 mg per day, though 3,000 mg is advised for chronic use.

Which route of administration completely bypasses first-pass hepatic metabolism?

Answer: Intravenous

Intravenous administration delivers drugs directly into systemic circulation, completely bypassing first-pass hepatic metabolism.

A patient taking phenytoin is started on valproic acid. What pharmacokinetic effect should the pharmacist anticipate?

Answer: Increased free phenytoin levels due to protein binding displacement

Valproic acid displaces phenytoin from protein binding sites and inhibits its metabolism, increasing free phenytoin levels and toxicity risk.

A pharmacist receives a telephone prescription for a Schedule III controlled substance. Which of the following is true?

Answer: Telephone orders are permitted and can be filled immediately

Schedule III and IV controlled substances may be received by telephone; the prescription can be filled based on the verbal order.