ATI RN
Chapter 26 principles of pharmacology Questions
Question 1 of 5
Monomer units of proteins are known as
Correct Answer: C
Rationale: Amino acids (C) are the monomer units of proteins, linked by peptide bonds (e.g., glycine in collagen), forming polypeptides via translation. Monosaccharides (A) build carbohydrates. Prosthetic groups (B) are non-protein enzyme parts. Purines (D) and nucleosides (original E) relate to nucleic acids. This biochemical foundation underpins protein drugs (e.g., insulin), where sequence dictates function, essential in pharmacology for therapeutic protein design and metabolism studies.
Question 2 of 5
A patient receives long-term, high-dose therapy with a sulfonamide. After approximately 3 weeks of therapy, the patient has a low-grade fever, rash, and muscle and joint pain. Which type of hypersensitivity accounts for these symptoms?
Correct Answer: C
Rationale: Type III hypersensitivity (C) accounts for these symptoms after 3 weeks of sulfonamide therapy, a serum sickness-like reaction from immune complexes depositing in tissues, causing inflammation (fever, rash, arthralgia). Type I (A) is immediate (e.g., anaphylaxis). Type II (B) is cytotoxic. Type IV (D) is delayed, T-cell mediated. No original E. This delayed onset, common with prolonged drug exposure, requires discontinuation and sometimes steroids, highlighting immune complex pharmacology in adverse reactions.
Question 3 of 5
Precipitation may occur when mixing aqueous solutions of meperidine hydrochloride with which of the following solutions?
Correct Answer: A
Rationale: Precipitation occurs with meperidine hydrochloride and sodium bicarbonate (A), as meperidine's protonated amine (acidic) reacts with bicarbonate's base, forming insoluble free base at pH > pKa (~8). Atropine sulfate (B) and sodium chloride (C) remain soluble. No option D or original E. This incompatibility, common with pH shifts, requires separate administration in IV therapy, ensuring drug stability and efficacy, a practical concern in clinical pharmacology.
Question 4 of 5
A 79-year-old man with end-stage Alzheimer's disease and dysphagia is taking multiple medications. Physical examination reveals xerostomia and a limited gag reflex. Which of the following routes of medication administration would provide the lowest serum drug concentration?
Correct Answer: A
Rationale: Enteral (A) administration would provide the lowest serum drug concentration in this patient due to the challenges posed by his dysphagia and limited gag reflex, which impair swallowing and gastrointestinal absorption. Enteral routes (e.g., oral) rely on GI uptake, which can be erratic or reduced in such conditions, further complicated by xerostomia reducing dissolution. Intramuscular (B) and intravenous (D) routes deliver drugs directly into systemic circulation, yielding higher concentrations. Intrathecal (C) targets the CSF, not serum, but still achieves systemic levels. Transdermal (original E) offers steady absorption but higher serum levels than enteral in this context. Given his swallowing difficulties, enteral drugs face significant barriers (e.g., incomplete absorption, first-pass metabolism), making it the least effective for systemic delivery, critical in managing polypharmacy in Alzheimer's patients.
Question 5 of 5
A 27-year-old man with HIV disease and hepatic insufficiency presents to his primary care physician complaining of rectal pain and bleeding with bowel movements. Physical examination reveals several internal and external hemorrhoids. The patient would like to avoid surgical therapy for this condition. Which of the following routes of drug administration would be preferred in this patient?
Correct Answer: D
Rationale: Rectal (D) administration is preferred for this patient with hemorrhoids, hepatic insufficiency, and HIV, delivering drugs (e.g., hydrocortisone suppositories) directly to the site, minimizing systemic exposure and hepatic metabolism. Enteral (A) risks first-pass metabolism, worsened by liver dysfunction. Intramuscular (B) and intravenous (C) are systemic, unnecessary for local relief. Transdermal (original E) is impractical for rectal tissue. Rectal's local action reduces systemic load, critical in hepatic compromise, offering rapid relief, patient comfort, and avoiding surgical risks in an immunocompromised state.