Pharmacy and Pharmacology practice questions

Answer: B) It can bind other drugs in the GI tract and reduce their absorption

Sucralfate acts locally in the GI tract and can bind other oral drugs, reducing their absorption. Other medications are therefore usually given about 2 hours before sucralfate.

• AIncorrect. Sucralfate is given on an empty stomach (about 1 hour before or 2 hours after meals). It is not activated by fat, and this does not explain why other drugs are given separately.
• BCorrect. Sucralfate binds drugs such as fluoroquinolones and digoxin in the gut and lowers how much is absorbed. Giving the other drug about 2 hours before sucralfate avoids the interaction.
• CIncorrect. Very little sucralfate is absorbed from the GI tract. It works locally on the mucosa, so its interactions happen in the gut, not through competition for kidney excretion.
• DIncorrect. Sucralfate coats ulcers on its own. Mixing it with antibiotics such as fluoroquinolones would actually cut their absorption.

Answer: A) Hypoadrenocorticism (Addison's disease)

DOCP is a mineralocorticoid used to replace aldosterone in dogs with primary hypoadrenocorticism (Addison's disease). Most patients also need a glucocorticoid such as prednisone.

• ACorrect. DOCP is a long-acting injectable mineralocorticoid that replaces the missing aldosterone in primary hypoadrenocorticism. It has no glucocorticoid activity, so dogs that also lack glucocorticoids usually need prednisone or prednisolone as well.
• BIncorrect. Cushing's disease involves too much cortisol and is treated with drugs that lower cortisol, such as trilostane. DOCP is a mineralocorticoid replacement and has no role in treating Cushing's.
• CIncorrect. Hyperthyroidism, mainly a feline disease, is managed with methimazole, radioiodine, surgery or diet, not with a mineralocorticoid.
• DIncorrect. Central diabetes insipidus is treated with desmopressin (DDAVP), a synthetic ADH analog. DOCP replaces aldosterone, not ADH.

Answer: A) IM absorption of diazepam is slow and erratic, and the injection is painful

Diazepam is absorbed slowly and unpredictably from muscle, and IM injection is painful, so it is given IV or rectally for seizures. Midazolam is the benzodiazepine of choice when the IM or intranasal route is needed.

• ACorrect. Diazepam is lipophilic and poorly water-soluble, and it comes in a propylene glycol vehicle. Absorption from muscle is slow and unpredictable, and the injection is painful. When an IM benzodiazepine is needed, midazolam is preferred because it is absorbed rapidly and reliably.
• BIncorrect. Diazepam is active itself; it does not need hepatic activation. Its active metabolites form after any route, so route-dependent activation is not why IM is avoided.
• CIncorrect. Diazepam is poorly water-soluble and lipophilic. Its problem after IM injection is slow, erratic absorption, not absorption that is too fast.
• DIncorrect. Cardiovascular effects such as hypotension are more likely with rapid IV injection, partly because of the propylene glycol vehicle. Hypotension is not the reason IM dosing is avoided.

Answer: B) Cats convert prednisone to its active form inefficiently

Prednisone must be converted in the liver to active prednisolone, and cats do this inefficiently. Giving prednisolone directly produces more reliable drug levels.

• AIncorrect. Slower elimination is not the reason. Cats prefer prednisolone because they activate prednisone poorly.
• BCorrect. Prednisone is a prodrug that the liver converts to prednisolone. Cats do this poorly, so giving prednisolone, which is already active, produces much higher drug levels.
• CIncorrect. Both drugs have similar, modest mineralocorticoid activity, so this does not explain the preference.
• DIncorrect. Heinz body anemia in cats is linked to oxidant toxins such as acetaminophen and onions, not prednisone.

Answer: B) Keep it in the refrigerator at about 36–46°F, away from the freezer section and sunlight

Store insulin in the refrigerator (about 36–46°F), never freeze it, and keep it away from heat and sunlight. Product labels set the mixing method and how long an opened vial can be used.

• AIncorrect. FDA guidance says not to use insulin that has been frozen. Freezing damages the protein and makes it less effective.
• BCorrect. FDA recommends refrigerating insulin at about 36–46°F and keeping it away from direct heat and sunlight. Freezing makes it unusable. Mix the vial exactly as the product label directs, because labels differ.
• CIncorrect. FDA advises keeping insulin away from direct heat. Extreme heat makes insulin less effective, and the damage grows with longer exposure.
• DIncorrect. FDA guidance says many insulins can stay unrefrigerated at 59–86°F for a set period (up to 28 days for many products). A short time out of the refrigerator does not by itself mean the vial must be thrown away. Follow the product label.

Answer: A) 5 mg/mL

• ACorrect. A 1% solution is 10 mg/mL.
• BIncorrect. That's 0.05%.
• CIncorrect. That's 5%.
• DIncorrect. That's 50%.

Answer: A) Deficient glucuronidation, which shunts more drug toward the toxic metabolite NAPQI

Cats glucuronidate acetaminophen poorly, so more of it becomes NAPQI. Once glutathione runs out, NAPQI causes methemoglobinemia, Heinz body anemia and liver damage, even at small doses.

• ACorrect. Cats have very low glucuronyl transferase activity and limited sulfation capacity. More acetaminophen is oxidized to NAPQI, which uses up glutathione and oxidizes hemoglobin. The result is methemoglobinemia, Heinz body hemolytic anemia and liver injury.
• BIncorrect. The problem is toxicity, not lack of effect. Cats clear acetaminophen poorly, and even small doses can be toxic or fatal.
• CIncorrect. Cats do have cyclooxygenase enzymes. The red cell damage comes from oxidation of hemoglobin by NAPQI, not from the drug binding red cell membranes.
• DIncorrect. Cytochrome P450 oxidation is the pathway that produces toxic NAPQI. The feline deficit is in glucuronide conjugation, not in P450 activity.

Answer: A) The prescribing veterinarian's name and address and the established name of the drug

Under 21 CFR 530.12, labeling for an extralabel-use drug must include the prescribing veterinarian's name and address, the established drug name, directions for use, cautionary statements, and any withdrawal times. Record items such as the diagnosis are not required on the label.

• ACorrect. 21 CFR 530.12 requires the prescribing veterinarian's name and address and the established name of the drug or of each active ingredient. It also requires directions for use, cautionary statements, and, for food animals, withdrawal, withholding, or discard times.
• BIncorrect. Neither item is among the labeling elements listed in 21 CFR 530.12. The DEA number relates to controlled substance registration and records, not this label rule.
• CIncorrect. The diagnosis and the reason for extralabel use belong in the medical record. They are not required labeling elements under 21 CFR 530.12.
• DIncorrect. 21 CFR 530.12 does not list the NDC or the client's phone number. It requires the drug's established name and the prescriber's name and address.

Answer: D) Behavior problems such as separation anxiety

• AIncorrect. It isn't an antibiotic.
• BIncorrect. It isn't a parasiticide.
• CIncorrect. It isn't a heart drug.
• DCorrect. It's an SSRI.

Answer: A) Penicillins

• ACorrect. A beta-lactam antibiotic.
• BIncorrect. That's doxycycline and similar.
• CIncorrect. That's enrofloxacin and similar.
• DIncorrect. That's gentamicin and similar.