Gastrointestinal & Systemic Pharmacology Review

Vocabulary flashcards summarizing key drugs, mechanisms, side effects, and nursing considerations from the lecture notes.

Peptic Ulcer Disease (PUD)

Upper GI disorder characterized by erosion of the gut wall, commonly triggered by H. pylori infection and NSAID use.

Gastroesophageal Reflux Disease (GERD)

Condition marked by heartburn due to reflux of stomach contents; H. pylori not typically involved.

Helicobacter pylori

Gram-negative bacterium linked to PUD; eradicated with combination antibiotic therapy.

Proton Pump Inhibitors (PPIs)

-prazole agents that markedly reduce gastric acid production; more effective but slower onset than H2 blockers.

Omeprazole

Prototype PPI; taken 30–60 min before meals once daily; long-term use ↓ Ca, Mg, B12, Fe.

Esomeprazole

PPI brand name Nexium; same class considerations as omeprazole.

Pantoprazole

PPI brand name Protonix; available IV or PO for acid suppression.

Lansoprazole

PPI brand name Prevacid; do not crush or split capsules.

H2 Receptor Blockers

-tidine drugs that decrease gastric acid by blocking histamine H2 receptors; faster onset than PPIs.

Famotidine

H2 blocker, brand Pepcid; preferred due to fewer drug interactions.

Ranitidine

H2 blocker, brand Zantac; withdrawn in some markets for impurity concerns.

Cimetidine

First H2 blocker; crosses the BBB and may cause confusion in the elderly.

Talicia

Fixed-dose combo of amoxicillin, rifabutin, and omeprazole for 14-day H. pylori eradication.

Antacids

OTC agents (e.g., calcium carbonate, magnesium/aluminum hydroxide) that neutralize gastric acid.

Calcium Carbonate

‘Tums’ antacid; excessive doses risk hypercalcemia and arrhythmia; 8 g/day max.

Magnesium Hydroxide

Milk of Magnesia; antacid and osmotic laxative; may cause diarrhea.

Aluminum Hydroxide

Antacid that causes constipation; often combined with Mg to balance GI effects.

Mylanta

Combination magnesium + aluminum antacid that balances diarrhea/constipation.

Sucralfate

Mucosal protectant that coats ulcers; take on an empty stomach for best effect.

Bismuth Subsalicylate

Pepto-Bismol; mucosal protectant with anti-diarrheal & mild anti-emetic properties.

Psyllium

Bulk-forming laxative (Group 3) that absorbs water to soften stool in 1–3 days.

Docusate Sodium

Stool softener (surfactant, Group 3) that allows water & fat to enter stool.

Bisacodyl

Stimulant laxative (Group 2) that increases peristalsis; suppository works fastest.

Senna

Plant-derived stimulant laxative producing semi-fluid stool in 6–12 h.

Polyethylene Glycol (PEG)

Osmotic laxative (Group 1) that draws water into bowel; used for bowel prep.

Loperamide

Anti-diarrheal that activates gut µ-opioid receptors to slow transit; high doses may cross BBB.

Ondansetron

5-HT₃ antagonist anti-emetic (Zofran); SE: headache, QT prolongation.

Metoclopramide

Pro-kinetic & anti-emetic; blocks dopamine in CTZ; risk of sedation & tardive dyskinesia.

Promethazine

First-gen antihistamine with anti-emetic effect; IV must be in large vein to avoid tissue injury.

Hyoscyamine

Antispasmodic for IBS; anticholinergic SE; on Beers list for elderly.

Dicyclomine

IBS antispasmodic; shares anticholinergic effects with hyoscyamine.

Cyclosporine

Calcineurin inhibitor immunosuppressant; nephrotoxic, causes hirsutism & gingival hyperplasia.

Tacrolimus

Calcineurin inhibitor with narrower therapeutic index; risk of alopecia & higher nephrotoxicity.

Methotrexate

DMARD that inhibits folate pathway; give with folic acid to protect healthy cells.

Anaphylaxis

Severe hypersensitivity with flushing, bronchospasm, hypotension; treat with epinephrine.

First-Generation H1 Antagonists

Sedating antihistamines (diphenhydramine, hydroxyzine, promethazine); strong anticholinergic effects.

Diphenhydramine

Benadryl; sedating antihistamine; long-term use linked to cognitive decline in elderly.

Second-Generation H1 Antagonists

Non-sedating antihistamines (loratadine, cetirizine, fexofenadine) that do not cross BBB.

Loratadine

Claritin; 2nd-gen antihistamine; avoid grapefruit/fruit juice which reduces absorption.

Cyclooxygenase (COX)

Enzyme pathway: COX-1 protects GI & platelets; COX-2 mediates pain, fever, inflammation.

Non-selective NSAIDs

Aspirin, ibuprofen, naproxen; inhibit COX-1 & COX-2, causing GI & renal risks.

Ibuprofen

OTC NSAID; analgesic/antipyretic; linked to thrombotic events; max adult dose 3200 mg/day.

Naproxen

Longer-acting NSAID (Aleve); similar risks to ibuprofen.

Aspirin (ASA)

Irreversible COX inhibitor; anti-platelet, analgesic, antipyretic; avoid in children (Reye’s).

Celecoxib

COX-2 selective NSAID (Celebrex); lower GI risk but higher CV thrombosis risk.

Acetaminophen

Analgesic/antipyretic without anti-inflammatory action; max 4 g/24 h; hepatotoxic in overdose.

N-acetylcysteine (NAC)

Antidote for acetaminophen overdose; replenishes hepatic glutathione.

Methicillin-Resistant Staphylococcus aureus (MRSA)

Gram-positive bacterium resistant to β-lactams; treated with vancomycin.

Clostridioides difficile (C. diff)

Gram-positive spore-forming bacterium causing severe diarrhea; often after broad-spectrum antibiotics.

Broad-Spectrum Antibiotic

Agent active against wide range of gram-positive & gram-negative bacteria; higher risk of superinfection.

Narrow-Spectrum Antibiotic

Targets specific pathogens; preferred once culture results known to limit resistance.

Beta-Lactamase

Bacterial enzyme that deactivates β-lactam antibiotics; combated with inhibitors like clavulanate.

Penicillins

β-lactam class; may be narrow (penicillin G) or broad (amoxicillin); watch for allergies.

Piperacillin-Tazobactam

Zosyn; extended-spectrum penicillin plus β-lactamase inhibitor.

Amoxicillin-Clavulanate

Augmentin; oral broad-spectrum penicillin with β-lactamase inhibitor.

Cephalosporins

β-lactams like ceftriaxone; risk of cross-allergy with penicillins & C. diff.

Carbapenems

Broadest β-lactams; resistant to β-lactamase; reserved for serious infections; risk of seizures.

Vancomycin

IV glycopeptide for MRSA & PO for C. diff; nephrotoxic, ototoxic; monitor trough levels.

Vancomycin Flushing Syndrome

Histamine-mediated red flushing from rapid vanco infusion; slow rate + antihistamine.

Macrolides

Protein-synthesis inhibitors (azithromycin, erythromycin); CYP450 inhibitors; QT prolongation.

Azithromycin

Z-pack macrolide; long half-life; fewer drug interactions than erythromycin.

Tetracyclines

Bacteriostatic protein synthesis inhibitors; photosensitivity & tooth discoloration; avoid in pregnancy.

Doxycycline

Tetracycline class; treats H. pylori & atypicals; take with food if GI upset.

Aminoglycosides

Protein synthesis inhibitors (gentamicin, tobramycin); nephro- & ototoxic; narrow therapeutic window.

Gentamicin

Prototype aminoglycoside; measure trough levels; avoid with other ototoxins.

Clindamycin

Lincosamide; high risk of C. diff; used for anaerobic & gram-positive infections.

Trimethoprim/Sulfamethoxazole

Bactrim; inhibits folate synthesis; treats UTIs; rare risk Stevens-Johnson syndrome.

Nitrofurantoin

Urinary antiseptic for uncomplicated UTIs; contraindicated near term pregnancy.

Rifampin

TB drug that turns bodily fluids red-orange; potent CYP inducer.

Isoniazid

First-line TB drug; major risk hepatotoxicity; give with vitamin B6 to prevent neuropathy.

Fluoroquinolones

-floxacin antibiotics (cipro, levo); QT prolongation & tendon rupture warnings.

Metronidazole

Flagyl; treats anaerobes & parasites; causes disulfiram reaction with alcohol.

Amphotericin B

IV antifungal for systemic mycoses; notable nephrotoxicity & infusion reactions.

Nystatin

Topical/oral ‘swish & swallow’ antifungal for candidiasis.

Fluconazole

Azole antifungal; oral or IV; inhibits fungal ergosterol synthesis.

Acyclovir

Antiviral nucleoside analog for HSV & VZV; renal adjustment required.