Respiratory Pharm Flashcards
(36 cards)
H1 blockers
Reversible inhibitors of H1 histamine receptors
1st generation H1 blockers:
Diphenhydramine, dimenhydrinate, chlorpheniramine
Names contain “-en/-ine” or “-en/-ate”
Clinical uses of 1st gen H1 blockers:
Allergy, motion sickness, sleep aid
Toxicity of 1st gen H1 blockers:
Sedation, antimuscarinic, anti-alpha-adrenergic
2nd generation H1 blockers:
Loratadine, fexofenadine, desloratadine, cetirizine.
Names usually end in “-adine”
Clinical uses of 2nd generation H1 blockers:
Allergy
Toxicity of 2nd generation H1 blockers
Far less sedating than 1st generation because of decreased entry into CNS
Guaifenesin
Expectorant - thins respiratory secretions; does not suppress cough
N-acetylcysteine
Mucolytic - can loosen mucus plugs in CF patients. Also used as an antidote for acetaminophen overdose.
Cleaves disulfide bonds within mucus glycoproteins.
Dextromethorphan
Antitussive (antagonizes NMDA glutamate receptors).
Synthetic codeine analog.
Mild opioid effect when used in excess.
Mild abuse potential
May cause serotonin syndrome if combined with other serotonergic agents.
Drug given for overdose of Dextromethorphan
Naloxone
Pseudoephedrine, phenylephrine mechanism:
sympathomimetic alpha-agonistic nonprescription nasal decongestants
Pseudoephedrine, phenylephrine clinical use:
Reduce hyperemia, edema and nasal congestion; open obstructed eustachian tubes.
Pseudoephedrine used illicitly to make methamphetamine
Pseudoephedrine, phenylephrine toxicity:
Hypertension. Can also cause CNS stimulation/anxiety (pseudoephedrine)
Endothelin R Antagonists:
Include Bosentan. Competetively antagonize endothelin-1 R’s. Leads to decreased pulmonary vascular resistance.
Hepatotoxic (monitor LFT’s)
PDE-5 Inhibitors:
Include sildenafil. Inhibit cGMP PDE5 and prolong vasodilatory effect of nitric oxide. Also used to treat erectile dysfunction.
Prostacyclin analogs:
Include epoprostenol, Iloprost. Prostacyclins (PGI2) w/vasodilatory effects on pulmonary and systemic arterial vascular beds. Inhibits platelet aggregation.
Side effects: flushing, Jaw pain
Asthma drugs:
Bronchoconstriction is mediated by 1. inflammatory processes, and 2. parasympathetic tone; therapy is directed at these 2 pathways
B2-agonist:
Albuterol, Salmeterol, formoterol
Used in asthmatics
Albuterol:
B2-agonist. Relaxes bronchial smooth muscle. Use during acute exacerbation of asthma.
Salmeterol, formoterol
Long acting B2 agonists for asthma prophylaxis. Adverse effects are tremor and arrhythmia.
Methylxanthines
Theophylline
Theophylline
Methylxanthine that likely causes bronchodilation by inhibiting phosphodiesterase (use in asthmatics). Increases cAMP levels, due to decreased cAMP hydrolysis.
Usage is limited by narrow therapeutic index (cardiotoxicity, neurotoxicity, ex. arrhythmias and seizures)
Metabolized by P-450.
Blocks actions of adenosine (a bronchoconstrictor)
Muscarinic antagonists:
Ipratropium (Atrovent)