Upper Respiratory Drugs

Question 1

First Gen Antihistamines

Answer 1

First Gen: diphenhydramine & promethazine

• PO, IV, IM
• Cross the BBB –> will affect the CNS
• Side effects:
  
  • CNS: depressant, drowsiness, dizziness, fatigue,
    disturbed coordination (FALL RISK)
  • PNS: anticholingeric effects (bear)
• Monitor for toxicity: excitation, hallucinations & seizures
• Secondary use: insomnia & motion sickness
• Contraindications: pregnancy, lactation, newborns, children & older adults
  
  • Urinary retention, BPH, glaucoma & HTN also
    contraindicated because of bear effects
• Nursing: assess breathing (CNS depressant = respiratory depression), VS (bear effects), I/Os (bear effect; urinary retention)
• CNS depression: avoid driving, watch for hangover effect, avoid other CNS depressants (ETOH, codeine)
• Warn against combination medications (decongestants)
• Vesicant: insure for IV patency
• Promethazine has high risk for extravasation

Question 2

Second Gen Antihistamines

Answer 2

Second Gen: cetirizine & fexofenadine

• PO, nasal spray
• Does not cross BBB; no sedative effect & no anticholinergic effect

Question 3

Decongestants

Answer 3

• Non-specific A1 agonists
• Ex: ephedrine (PO), pseudoephedrine (PO)
• Nasal spray/inhalation mist, ophthalmic, IM, SubQ, IV, PO
• MOA:
  
  • A1: peripheral vasoconstriction (decreased swelling,
    stuffiness & rhinorrhea)
  • A & B: worsening HTN, BPH & tachycardia
• Side effects: in CNS –> restlessness, jitteriness, nervousness (avoid stimulants)
• Nursing:
  
  • Nasal spray when sitting (not while supine)
  • Avoid frequent use of nasal spray –> multiple doses
    may cause paradoxical congestion b/c of irritation
  • Causes tolerance –> need to taper off to avoid
    rebound congestion (<3-5 days)
  • Precautions due to vasoconstriction (CVA, dysrhythmia,
    tachycardia, HTN, CAD, RF)
  • Precautions b/c of adrenergic response:
    
    • hyperglycemia for diabetic pts
    • avoid in glaucoma & BPH pts
    • works against antidepressants
• Combination cold remedies (decongestants & antihistamines) can often lead to overdoses

Question 4

Menthol

Answer 4

• Antitussive
• Indication: dry cough & to avoid further throat irritation
• Menthol in cough lozenges –> local anesthetic obtained from mint

Question 5

Benzonatate & Dextromethorphan

Answer 5

• Non-opioid antitussive
• Benzonatate (Rx; PO)
• Dextromethorphan ( OTC syrup, lozenges)
• MOA: suppress the cough center in the medulla
• Side effects: drowsiness, dizziness, euphoria with high dose
• Risk of abuse
• Structurally similar to opioids but does not have analgesic properties

Question 6

Codeine

Answer 6

• Opioid antitussive
• Often in combination with antihistamine, decongestant or expectorant
• MOA: suppresses the cough by increasing cough threshold in CNS (prodrug)
• Side effects: drowsiness, resp. depression, dizziness, nausea, constipation, hypotension
  
  • FALL RISK
• Contraindications: resp. disease, alcohol, head trauma
• Risk for abuse; reversed by naloxone

Question 7

Guaifenesin

Answer 7

• expectorant
• MOA: increasing respiratory tract fluid
• PO (tab, capsule, fluid)
• Contraindications: never to kids <4yo
• Nursing: increase hydration
• Combinations with analgesics, antihistamines, decongestants & antitussives can lead to OD

Question 8

Guaifenesin/Dextromethorphan

Answer 8

• Expectorant & antitussive
• OTC
• Cautions: drowsiness & dizziness
• Want you to cough mucus up, but also don’t want you to cough too much because it can irritate the linings more = expectorant & antitussive

Question 9

Intranasal Glucocorticoids (-onide, -sone, -one)

Answer 9

• Ex: budesonide, fluticasone, mometasone, triamcinolone –> all are nasal sprays
• Side effects: dryness of nasal mucosa & epistaxis
  
  • Manage dryness with saline nasal spray
• Contraindications: pregnancy, URI (don’t want to decrease inflammation especially if it is a viral infection)
• Nursing:
  
  • Scheduled, maintenance drug
  • 7-21 days for peak effect
  • Shorten length of use to avoid opportunistic infection