Pharmacology: Cough & Cold, Gastrointestinal, and Lower Respiratory Agents

Vocabulary practice flashcards covering respiratory, gastrointestinal, cough/cold, and lower airway pharmacological agents.

Codeine

A centrally acting narcotic antitussive used for severe, painful coughs that carries risks of drowsiness, respiratory depression, constipation, and abuse potential.

Benzonatate

A prescription peripherally acting antitussive that anesthetizes stretch receptors in the respiratory passages and pleura to reduce the cough reflex.

Antitussive Liquid Administration Rule

The clinical instruction requiring patients to wait $30\,\text{minutes}$ after taking cough syrup before drinking any liquid so the medication can properly coat the throat.

Pseudoephedrine

An oral sympathomimetic decongestant kept behind the pharmacy counter due to regulatory sales restrictions, used to relieve sinus pressure and congestion.

Oxymetazoline

A topical nasal decongestant spray that stimulates alpha-adrenergic receptors to cause local vasoconstriction; restricted to no more than $3\,\text{days}$ of continuous use to prevent rebound congestion.

Chlorpheniramine

A first-generation antihistamine that competitively antagonizes histamine at $H_1$ receptors, commonly causing sedation and anticholinergic effects such as dry mucous membranes, urinary retention, and constipation.

Loratadine

A second-generation antihistamine that competitively blocks histamine at $H_1$ receptors with significantly reduced sedating and anticholinergic properties compared to first-generation agents.

Guaifenesin

An expectorant that stimulates respiratory tract secretions and reduces their viscosity to ease mucus clearance; clinical administration requires increasing oral fluid intake.

Diphenoxylate with Atropine

A Schedule $V$ controlled substance antidiarrheal combination wherein diphenoxylate acts as the active opioid agent to slow gut transit and atropine is included to discourage deliberate abuse.

Loperamide

A poorly absorbed non-opioid antidiarrheal agent that does not cross the blood-brain barrier and decreases diarrhea symptoms by slowing intestinal motility.

Psyllium

A bulk-forming fiber agent that absorbs water to create a soft, gelatin-like mass that stimulates defecation; must always be administered with at least $8\,\text{oz}$ of water to prevent intestinal or esophageal obstruction.

Bismuth Subsalicylate

An antidiarrheal agent possessing antisecretory and anti-inflammatory properties from salicylate and antibacterial actions from bismuth; commonly causes temporary harmless darkening of the tongue and stool.

Rifaximin

An oral antibiotic that alters the gastrointestinal microbiome, prescribed as a $2\,\text{week}$ course for irritable bowel syndrome with diarrhea (IBS-D) that may be repeated every $6\,\text{months}$ as needed.

Docusate Sodium

A surfactant stool softener that lowers surface tension to allow water and lipids to penetrate fecal mass, used prophylactically over several days to prevent painful straining.

Bisacodyl

A stimulant laxative that irritates smooth muscle to promote GI motility and draws fluid into the bowel, producing semi-fluid stools within $6\text{--}12\,\text{hours}$ orally or $15\text{--}60\,\text{minutes}$ rectally.

Laxative Abuse Cycle

The repeated overuse of potent cathartics that empties the entire colon, requiring $2\text{--}5\,\text{days}$ to refill, leading users to take repeated doses and causing chronic dehydration, electrolyte imbalances, and loss of defecatory reflexes.

Ondansetron

A selective serotonin $5\text{--}HT_3$ receptor antagonist antiemetic used for gastroenteritis, post-operative nausea, and chemotherapy-induced vomiting in adults and children down to $6\,\text{months}$ of age.

Scopolamine

An anticholinergic antiemetic agent indicated primarily for the prophylaxis and treatment of motion sickness.

Prostaglandins (Gastric Protective Factors)

Endogenous mucosal protectors (such as $PG\,E$) that stimulate protective mucus and bicarbonate secretion, suppress gastric acid production, and promote vasodilation to maintain mucosal blood flow.

Helicobacter pylori

A gram-negative bacterium that colonizes the space between epithelial cells and the mucous layer of the stomach, representing a primary hostile cause of peptic ulcer disease.

Pepsin

A proteolytic digestive enzyme that breaks down protein in the stomach lining and is activated from pepsinogen exclusively in an acidic milieu where $pH < 3$.

Antacids

Alkaline chemical agents that neutralize hydrochloric acid and raise gastric $pH \ge 3.5$ to inhibit pepsinogen activation; magnesium forms cause diarrhea, while calcium and aluminum formulations cause constipation.

Famotidine

An $H_2$-receptor antagonist that selectively inhibits histamine at parietal cell $H_2$ receptors to suppress basal and stimulated gastric acid production in PUD and GERD.

Proton Pump Inhibitors (PPIs)

Potent antisecretory drugs, including omeprazole and pantoprazole, that inhibit the gastric hydrogen-potassium ATPase pump, achieving up to a $97\%$ reduction in gastric acid secretion within $2\,\text{hours}$.

Sucralfate

A mucosal protectant agent that undergoes chemical cross-linking in gastric acid to form a viscous, paste-like barrier over ulcer craters to shield them from acid, pepsin, and bile.

GERD Non-Pharmacologic Management

Lifestyle interventions to prevent esophageal acid reflux, including avoiding trigger foods/caffeine, losing excess weight, smoking cessation, avoiding the supine position for $3\text{--}4\,\text{hours}$ postprandial, and elevating the head of the bed $4\text{ to }6\,\text{inches}$.

Acetylcysteine

A nebulized mucolytic that cleaves disulfide bonds to liquify thick respiratory mucus within $1\,\text{minute}$; also serves as an intravenous antidote for acetaminophen overdose.

Albuterol

An inhaled short-acting beta-2 agonist (SABA) that induces rapid bronchodilation via smooth muscle relaxation; used as a first-line rescue inhaler for acute bronchospasm up to every $4\,\text{hours}$ as needed.

Levalbuterol

A short-acting beta-2 adrenergic agonist (SABA) formulated as the pure R-enantiomer to produce bronchodilation with significantly fewer cardiac adverse effects, such as tachycardia, than racemic albuterol.

Salmeterol

An inhaled long-acting beta-2 agonist (LABA) bronchodilator utilized exclusively on a regular schedule for chronic maintenance and control of asthma and COPD, never for acute rescue.

Ipratropium

An inhaled short-acting anticholinergic bronchodilator with an onset of $5\text{--}15\,\text{minutes}$ and duration of $4\text{--}6\,\text{hours}$ that works by blocking muscarinic cholinergic receptors.

Tiotropium

A long-acting inhaled muscarinic antagonist (anticholinergic) administered once daily via dry powder inhaler or mist inhaler for maintenance treatment of chronic airway obstruction.

Inhaled Corticosteroids (ICS)

Airway anti-inflammatory agents, including fluticasone and beclomethasone, that suppress cytokine release, decrease airway edema, and diminish bronchial hyperreactivity as foundational controller therapies.

HPA Axis Suppression

The suppression of the hypothalamic-pituitary-adrenal axis caused by prolonged exogenous corticosteroid therapy, requiring gradual dosage tapering to prevent life-threatening acute adrenal crisis.

Glucocorticoid Burst Therapy

A short-term oral steroid regimen providing a fixed, high dose of corticosteroid (such as prednisone $60\,\text{mg}$ daily) for $5\,\text{days}$ without requiring a gradual taper.

Montelukast

An oral leukotriene receptor antagonist (LTRA) controller prescribed for asthma and allergies in patients aged $12\,\text{months}$ and older, which carries a boxed warning for neuropsychiatric adverse reactions.

Omalizumab

A subcutaneous monoclonal antibody administered every $2\text{--}4\,\text{weeks}$ that binds selectively to circulating free IgE to prevent mast cell degranulation; requires clinical observation during the first dose due to risk of anaphylaxis.

MDI Spacer

An add-on valved holding chamber that attaches to a metered-dose inhaler, reducing oropharyngeal drug impaction and increasing active medication delivery to the lungs from $9\%$ to $21\%$.