URI Pharmacology

Vocabulary practice flashcards covering upper respiratory tract pharmacology, including H1 and H2 antihistamines, sympathomimetic decongestants, antitussives, expectorants, and mucolytics.

Histamine

A substance involved in nerve transmission, capillary dilation, smooth muscle contraction, gastric acid secretion, and heart rate control.

$H_1$ Receptors

Histamine receptors that mediate smooth muscle contraction and capillary dilation, serving as the target for traditional allergy medications.

$H_2$ Receptors

Histamine receptors that mediate heart rate and gastric acid secretion.

$H_2$ Blockers

Antihistamines acting on the GI system (such as cimetidine, rantidine, famotidine, and nizatidine) used most commonly for GERD treatment.

$H_1$ Blockers

Medications commonly called antihistamines that bind to $H_1$ receptors and block histamine release to treat nasal allergies, seasonal allergies, sneezing, and runny nose.

1st Generation Antihistamines

Sedating antihistamines indicated for mild allergic reactions, motion sickness, and insomnia, which produce anticholinergic side effects (drowsiness, dizziness, dry mouth, urinary retention, and constipation).

diphenhydramine (Benadryl)

A 1st generation sedating antihistamine administered PO or IV, indicated for mild allergic reactions, motion sickness, insomnia, and severe anaphylactic reactions.

meclizine

A 1st generation sedating antihistamine primarily given for motion sickness.

promethazine

A 1st generation sedating antihistamine primarily given for motion sickness.

2nd Generation Antihistamines

Non-sedating oral antihistamines indicated for allergic rhinitis and chronic idiopathic urticaria that cause fewer side effects, less drowsiness, and less fatigue.

loratadine (Claritin)

An oral non-sedating 2nd generation antihistamine used to treat allergic rhinitis and chronic idiopathic urticaria.

fexofenadine (Allegra)

An oral non-sedating 2nd generation antihistamine used to treat allergic rhinitis and chronic idiopathic urticaria.

cetirizine (Zyrtec)

An oral non-sedating 2nd generation antihistamine used to treat allergic rhinitis and chronic idiopathic urticaria.

Sympathomimetics (Decongestant)

Drugs that mimic the SNS and activate $\alpha_1$-adrenergic receptors, causing vasoconstriction of blood vessels to shrink nasal turbinates and open nasal passages.

Rebound Nasal Congestion

Nasal congestion that occurs if a sympathomimetic decongestant is abruptly stopped after prolonged use of more than $4\text{ days}$.

pseudoephedrine

A sympathomimetic decongestant with potential for abuse as an active ingredient in methamphetamine, subject to state pharmacy counter purchase limits.

Antitussive

A cough suppressant medication class (e.g., dextromethorphan, codeine, benzonatate) that directly suppresses the cough reflex in the brain.

benzonatate (Tessalon Perles)

An oral antitussive medication used as a cough suppressant for acute or chronic coughs.

Expectorant

A drug class that reduces the surface tension of secretions, helping to thin mucus and make it easier to expectorate.

guaifenesin (Mucinex)

An expectorant indicated to decrease mucus in colds, bronchitis, and related respiratory conditions.

Mucolytics

Medications indicated for bronchopulmonary disease and cystic fibrosis that decrease the viscosity of mucus, making it easier to cough.

acetylcysteine (Mucomyst)

A mucolytic given via nebulizer or tracheostomy that thins mucus viscosity; notable for a foul smell and potential side effect of bronchospasm.