Drugs

What drug type (drugs) should we worry about rebound effects?

Nasal decongestants (phenylephrine - Sudafed PE, phenylephrine (0.25-1%), and oxymetazoline-Afrin)

Azelastine

• Brand: Astepro

• Class/MOA: 2nd-generation H1 antagonist (nasal/ophthalmic)

• Indication: long lasting or seasonal allergic rhinitis, Allergic conjunctivitis

• Key notes:

  • Onset 15–30 min (fast for allergy)

  • Taste disturbance is common

  • Avoid alcohol/CNS depressants → can cause drowsiness

  • Re-prime if unused >3 days

Benzonatate

• Brand: Tessalon Perles

• Class/indication: Non-narcotic antitussive

• MOA: Anesthetizes tissues of the lungs/pleura responsible for the cough reflex

• Key notes:

  • Swallow whole with cold water (chewing = laryngospasm)

  • Fatal overdose in kids <10

  • Max single dose of 200mg, daily dose of 600mg/day

Olopatadine

• Brand: Patanase (DSC)

• Class/MOA: 2nd-generation H1 antagonist (nasal/ophthalmic)

• Indication: Seasonal allergies, allergic conjunctivitis

• Key notes:

  • Onset ~30 min

  • Alternate between nostrils

  • Less sedating than azelastine (no alcohol or CNS depressants)

  • Nasal ulcers/epistaxis → stop & evaluate

  • Wait 10 min before contacts (ophthalmic)

Diphenhydramine

• Brand: Benadryl

• Class/MOA: 1st-generation H1 antagonist + anticholinergic effects

• Indication: Symptom relief of allergies

• Key notes:

  • Sedating, anticholinergic (anti-SLUDGE)

  • Beers Criteria (avoid elderly)

  • Toxicity in children can cause hallucinations, convulsions, or death

  • Avoid in glaucoma, BPH, asthma

Cetirizine

• Brand: Zyrtec

• Class/MOA: 2nd-generation H1 antagonist (oral)

• Indication: Allergic rhinitis

• Key notes:

  • Mild sedation possible (More sedating than loratadine/fexofenadine)

  • Renal dose adjustment

What are anti-tussives, anti-histamines, anti-pyretics, and expectorants used for?

Anti-cough, anti-allergies, anti-fevers, thin and loosen mucus

Loratadine

• Brand: Claritin

• Class/MOA: 2nd-generation H1 antagonist (oral)

• Indication: Allergic rhinitis

• Key notes:

  • Non-drowsy → still side effects when used with sedative drugs/alcohol

  • Renal/hepatic adjustment may be needed

Fexofenadine

• Brand: Allegra

• Class: 2nd-generation H1 antagonist (oral)

• MOA: Peripheral H1 blockade (minimal CNS penetration)

• Indication: Upper respiratory allergies

• Key notes:

  • Least sedating antihistamine

  • Separate juice by ≥4 hours (↓ absorption)

  • May need renal dose adjustment

Pseudoephedrine

• Brand: Sudafed (12h, 24h)

• Class: α/β-adrenergic agonist (oral)

• MOA: α-agonism → vasoconstriction of nasal mucosa; β-agonism → ↑ HR and contractility + bronchial relaxation

• Indication: Nasal congestion

• Key notes:

  • Causes HTN, insomnia, tachycardia

  • DDIs with MAOIs, SSRIs, SNRIs, Alpha-1 blockers, spironolactone

Phenylephrine (nasal)

• Brand: 4-Way

• Formulations: Nasal spray (0.25–1%) → oral form (phenylephrine - Sudafed PE) is ineffective for decongestion (FDA)

• Class/indication: α-agonist decongestant

• MOA: Local vasoconstriction in the nasal mucosa

• Key notes:

  • Max 3 days → rebound congestion

Oxymetazoline

• Brand: Afrin

• Formulations: Nasal spray

• Class/indication: α-agonist decongestant

• MOA: Vasoconstriction of the nasal mucosa arterioles

• Key notes:

  • Duration up to 12 hrs

  • Max 3 days → rebound congestion

  • Shake & prime before use

Dextromethorphan

• Brand: Delsym, Robitussin

• Class: Antitussive

• MOA: Suppresses medullary cough center (by stimulating sigma [breaking] receptors)

• Key notes:

  • Abuse potential

  • Avoid with MAOIs, SSRIs → serotonin syndrome

  • Best for dry, nonproductive cough

Beclomethasone

• Brand: QVAR, QVAR RediHaler

• Class: Inhaled corticosteroid (ICS)

• Indication: Asthma maintenance/prophylaxis

• MOA: Alters gene transcription → ↓ airway inflammation, ↓ exacerbations

• Key notes:

  • NOT a rescue inhaler

  • Rinse mouth → prevent oral candidiasis

Budesonide

• Brand: Pulmicort, Pulmicort Flexhaler

• Formulations: Flexinhaler, nebulizer

• Class: Inhaled corticosteroid (ICS)

• Indication: Asthma maintenance/prophylaxis

• MOA: Alters gene transcription → ↓ airway inflammation, ↓ exacerbations

• Key notes:

  • Only ICS with nebulized pediatric option

  • Delayed onset (days–1 week)

  • Rinse mouth → prevent oral candidiasis

Fluticasone

• Brand: Flovent (propionate), Arnuity Ellipta (furoate)

• Formulations: Diskus, inhaler

• Class: Inhaled corticosteroid (ICS)

• Indication: Asthma maintenance/prophylaxis

• MOA: Alters gene transcription → ↓ airway inflammation, ↓ exacerbations

• Key notes:

  • Once-daily option = Arnuity Ellipta

  • CYP3A4 interactions (↑ steroid exposure)

  • Not for acute symptoms

Mometasone

• Brand: Asmanex

• Formulations: Twisthaler, inhaler

• Class: ICS

• Indication: Asthma maintenance

• MOA: Inhibits inflammatory mediator production

• Key notes:

  • Lower systemic bioavailability

  • Rinse mouth

  • Delayed onset

Montelukast

• Brand: Singulair

• Class: Oral Leukotriene receptor antagonist (LTRA)

• Indication: Allergic rhinitis, asthma (prophylaxis, chronic), exercise-induced bronchoconstriction (prophylaxis)

• MOA: Blocks leukotriene D4 → ↓ bronchoconstriction & inflammation

• Key notes:

  • Boxed warning: neuropsychiatric effects

  • Use only if other therapies fail

  • ADE: neuropsychiatric events (aggresion, depression, insomnia, etc.)

Fluticasone

• Brand: Flonase

• Class: Intranasal corticosteroid (INCS)

• Indication: Upper respiratory allergies

• MOA: Unknown; believed to inhibit T cell proliferation, reduce inflammatory cytokine response, and levels of mast cells, eosinophils, and basophils

• Key notes:

  • Most effective monotherapy for allergic rhinitis

  • Delayed onset (days → 1 week)

  • Local effect → local AEs: epistaxis, nasal irritation

  • Not PRN — must use daily

Triamcinolone

• Brand: Nasacort

• Class: Intranasal corticosteroid (INCS)

• Indication: Upper respiratory allergies

• MOA: Binds to GR → Controls the rate of protein synthesis, depresses the migration of fibroblasts, reverses capillary permeability, and stabilizes lysosomal membranes to prevent/control inflammation

• Key notes:

  • Full effect ~1 week

  • Adrenal suppression is possible with chronic use

  • Max 2 sprays in each nostril once daily

Cromolyn sodium

• Brand: NasalCrom

• Indication: Allergic rhinitis (pre-exposure prophylaxis)

• Class: Mast cell stabilizer

• MOA: Blocks calcium influx into the cell → prevents mast cell degranulation (prevents release of histamine)

• Key notes:

  • Preventative only (not for acute symptoms)

  • Takes more than 2 weeks to work

  • Requires frequent dosing (3–6×/day)

Artificial tears

• Class: Ophthalmic lubricant

• MOA: Moisturizes ocular surface; dilutes irritants

• Key notes:

  • Symptomatic relief only

    • No antimicrobial activity (does not treat or prevent an eye infection)

  • Remove contacts before use

Acetaminophen

• Brand: Tylenol (IV: Ofirmev)

• Class/indication: Antipyretic; non-opioid analgesic (for fever and pain)

• MOA: Unknown; Central inhibition of prostaglandin synthesis (does not target COX)

• Key notes:

  • No anti-inflammatory effect

  • BBW: hepatotoxicity

  • Max daily dose: 4 g (≤2 g if liver disease)

  • Safe in pregnancy

  • Many combo products → overdose risk

  • Acetylcysteine → antidote

Aspirin

• Class: Nonselective NSAID; antiplatelet; salicylate

• Indication: Low doses: anti-thrombotic, Higher dosesantipyretic, analgesic → anti-inflammatory effects

• MOA: Irreversibly inhibits COX-1 & COX-2 → ↓ prostaglandins & thromboxane A₂

• Key notes:

  • Antiplatelet effect lasts the life of a platelet

  • Reye’s syndrome risk → avoid kids/teens with viral illness

  • Can cause tinnitus (toxicity clue)

  • ↑ GI bleeding risk

Ibuprofen

• Brand: Advil, Motrin

• Class: NSAID

• Indication: Fever, pain (headache), sore throat, common cold/flu

• MOA: Reversible COX-1 & COX-2 inhibition

• Key notes:

  • OTC max 1200 mg/day

  • Take with food

  • BBW: ↑ CV & GI risk

  • Avoid chronic use with aspirin (↓ antiplatelet effect)

Naproxen

• Brand: Aleve, Naprosyn

• Class: NSAID

• Indication: Fever

• MOA: Reversible COX-1 & COX-2 inhibition

• Key notes:

  • Longer half-life than ibuprofen

  • OTC max 600 mg/day

  • BBW: ↑ CV & GI risk

  • Avoid in CABG patients, limit alcohol

Diclofenac

• Brand: Cambia, Zipsor

• Class: NSAID

• Indications: Acute pain, osteoarthritis (topical solution)

• MOA: Reversible COX-1 & COX-2 inhibition

• Key notes:

  • BBW: ↑ CV & GI risk

  • Take with food (except Zorvolex)

  • Avoid in CABG patients, limit alcohol

Celecoxib

• Brand: Celebrex

• Class: COX-2 selective NSAID

• Indication: Acute pain

• MOA: Selective COX-2 inhibition → ↓ inflammation (spares platelets)

  • Prothrombotic effect possibility

• Key notes:

  • BBW: ↑ CV & GI risk

    • Less GI toxicity (unless combined with aspirin)

  • Sulfa allergy contraindication

  • Limit alcohol + use with other NSAIDs

Oseltamivir

• Brand: Tamiflu

• Class: Antiviral (neuraminidase inhibitor)

• MOA: Inhibits neuraminidase → prevents release of influenza A & B virions from infected cells

• Key notes:

  • Start within 48 hours of symptoms

  • Used for post-exposure prophylaxis

  • Neuropsychiatric effects (esp kids)

  • Requires renal dose adjustment

  • DDI: Dichlorphenamide (↑ oseltamivir levels)

Guaifenesin / Codeine / Pseudoephedrine

• Formulation: PO syrup

• Class: Expectorant + opioid antitussive + decongestant

• Indication: Cough suppressant

• MOA:

  • Guaifenesin → ↓ mucus viscosity

  • Codeine → suppresses the medullary cough center

  • Pseudoephedrine → α-agonist vasoconstriction

• Key notes:

  • Sedation + respiratory depression risk

  • Avoid in kids, MAOIs (2 week washout), CV disease

  • Use the lowest dose, shortest duration

Guaifenesin

• Brand: Mucinex

• Class: Expectorant

• MOA: ↑ hydration of respiratory secretions → ↓ viscosity

• Key notes:

  • Best for acute and productive cough

  • ER not for kids <12

  • Need to increase fluids for the medication to work properly

Albuterol

• Brand: Ventolin HFA, ProAir RespiClick

• Class: SABA

• Indication: Treatment or prevention of bronchospasm in asthma; prevention of exercise-induced bronchospasm

• MOA: β₂-agonist → bronchial smooth muscle relaxation

  • Minimal effects on HR

• Key notes:

  • First-line rescue inhaler

  • Overuse = poor asthma control

  • SEs: tremor, tachycardia, nervousness, increased serum glucose

  • Use PRN only

Levalbuterol

• Brand: Xopenex

• Class: SABA

• Indication: Treatment or prevention of bronchospasm in asthma

• MOA: Selective β₂-agonist (R-enantiomer of albuterol)

  • Minimal effects on HR

• Key notes:

  • Similar efficacy to albuterol

  • Use PRN only

Formoterol

• Brand: Perforomist

• Formulations: Inhaler + Inhaler solution

• Class: LABA

• Indication: Asthma (with ICS), COPD maintenance, prevention of exercise-induced bronchospasm

• MOA: Long-acting β₂-agonist → sustained bronchodilation (bronchial smooth muscle relaxation)

• Key notes:

  • Rapid onset (unique among LABAs)

  • Never monotherapy in asthma

  • Not for acute bronchospasm

Salmeterol

• Brand: Serevent Diskus

• Formulation: Diskus

• Class: LABA

• Indication: Asthma maintenance (with ICS), COPD maintenance, prophylaxis of exercise-induced bronchospasm in patients ≥4

• MOA: Long-acting β₂-agonist → sustained bronchodilation (bronchial smooth muscle relaxation)

• Key notes:

  • BBW: LABA monotherapy ↑ asthma-related death

  • Slow onset → not rescue

  • Always combine with ICS in asthma

  • Not for acute bronchospasm

Ipratropium

• Brand: Atrovent HFA

• Formulation: pMDI

• Class: SAMA

• Indication: COPD maintenance; off-label for moderate-severe asthma exacerbations

• MOA: Blocks M3 receptors → ↓ bronchoconstriction

• Key notes:

  • Not for acute SOB → Not first-line rescue

  • Sinusitis, GI upset, UTI, etc.

Tiotropium

• Brand: Spiriva Handihaler, Spiriva Respimat

• Formulations: DPI, SMI

• Class: LAMA

• Indication: COPD maintenance; add-on maintenance asthma therapy (respimat)

• MOA: Long-acting M3 antagonism → bronchodilation

• Key notes:

  • Once-daily dosing

  • Not for acute SOB → Not first-line rescue

Umeclidinium

• Brand: Incruse Ellipta

• Formulation: DPI

• Class: LAMA

• Indication: COPD maintenance

• MOA: Competitive and reversible M3 antagonism → bronchodilation

• Key notes:

  • Milk protein allergy = contraindicated

  • Once daily

  • Not for acute SOB → Not first-line rescue