Guide: (Latest Update) Complete Q&A | Grade A | 100% Correct (Verified
Answers)
Subject: Differential Diagnosis & Primary Care (NR511) – Midterm Comprehensive: Clinical Reasoning,
Pharmacology, Dermatology, ENT, Ophthalmology, GI, Infectious Disease, Geriatrics
Source: Midterm Study Guide – Diagnostic Testing, Antibiotic Selection, Rash Identification, Hearing
Loss, Glaucoma, GERD, Otitis Media, Health Promotion
Format: Q&A Comprehensive Study Guide with Rationale – 100% Verified Answers
Verified: Latest Update | Grade A Guaranteed
1: Which medications used to treat nausea and vomiting work by affecting the chemoreceptor
trigger zone, thereby stimulating upper gastrointestinal motility and increasing lower esophageal
sphincter pressure?
Correct Answer: Antidopaminergic agents (metoclopramide/Reglan) and cholinergic agents – affect
CTZ, stimulate GI motility, increase LES pressure
1. Metoclopramide is a prokinetic agent that blocks dopamine receptors in CTZ.
2. Increases gastric emptying and LES tone; used for diabetic gastroparesis, GERD, CINV.
3. Black box warning: tardive dyskinesia with long-term use.
2: The antibiotic of choice for recurrent acute otitis media (AOM) and/or treatment failure in
children is:
Correct Answer: Amoxicillin and potassium clavulanate (Augmentin)
1. Augmentin covers beta-lactamase-producing organisms (H. influenzae, M. catarrhalis).
2. First-line: amoxicillin for uncomplicated AOM. Treatment failure after 48-72 hours or
recurrent AOM → Augmentin.
3. Alternative: ceftriaxone IM if penicillin allergy.
3: A 67-year-old female on multiple medications with newly diagnosed GERD – what medication
should the clinician recommend she refrain from using?
Correct Answer: Nonsteroidal anti-inflammatory drugs (NSAIDs)
1. NSAIDs cause gastric irritation and can exacerbate GERD symptoms.
2. May also cause peptic ulcers and bleeding.
3. Consider acetaminophen for pain if needed.
4: A 30-year-old male with intermittent diarrhea after antacid use – likely cause?
Correct Answer: Antacids may contain magnesium, which decreases bowel transit time and contains
poorly absorbed salts resulting in osmotic draw of fluid – diarrhea
1. Magnesium-containing antacids (Mylanta, Maalox) cause osmotic diarrhea.
2. Aluminum-containing antacids cause constipation.
3. Swith to calcium carbonate or non-magnesium antacid if diarrhea bothersome.
, 5: A 72-year-old male worried because he only has a bowel movement every three days – clinician
response?
Correct Answer: There is no such thing as a "normal" pattern of defecation. Patterns vary widely based
on dietary habits, fluid intake, psychological stress, etc. Defecating every third day could be routine for
him.
1. Normal stool frequency ranges from three times daily to three times weekly.
2. Assess for change from baseline, not absolute frequency.
3. Rome IV criteria for constipation: <3 stools/week, straining, hard/lumpy stools.
6: A 52-year-old female with suspected gastric ulcer undergoing EGD – she's concerned because
gastric ulcers can be malignant. Clinician response?
Correct Answer: About 95% of gastric ulcers are benign, even though they may look malignant on x-
ray
1. Only 5% of gastric ulcers are malignant.
2. Indications for biopsy: irregular margins, large size (>2-3 cm), associated with weight
loss/bleeding.
3. Duodenal ulcers are almost always benign.
7: A 29-year-old female returned from Central America with traveler's diarrhea – best treatment?
Correct Answer: Supportive care (fluid repletion, oral rehydration, loperamide for mild cases;
antibiotics for severe/febrile/bloody diarrhea)
1. Traveler's diarrhea usually self-limited (3-7 days).
2. Most common pathogen: E. coli; antibiotics: ciprofloxacin, azithromycin (pregnancy).
3. Avoid antibiotics if afebrile, non-bloody, mild symptoms.
8: A 82-year-old female with IBS, chronic constipation, and diverticulitis – pharmacologic agent?
Correct Answer: Bulking agent (fiber – psyllium, methylcellulose)
1. Bulk-forming laxatives are first-line for chronic constipation and IBS-C.
2. Increase fiber gradually to avoid bloating/gas; maintain hydration.
3. Avoid stimulant laxatives long-term.
9: A 26-year-old male returned from camping with acute gastroenteritis after eating home-canned
vegetables – likely pathogen?
Correct Answer: Clostridium botulinum
1. C. botulinum spores survive in improperly canned foods, produce neurotoxin.
2. Symptoms: nausea, vomiting, weakness, diplopia, dysphagia, descending paralysis.
3. Requires antitoxin and respiratory support.