Reversible inhibitors of H1 histamine receptors that enter CNS
H1 blockers (1st generation)
Reversible inhibitors of H1 histamine receptors that do not enter CNS (much)
H1 blockers (2nd generation)
Expectorant - thins respiratory secretions; does not suppress cough reflex
Guaifenesin
Mucolytic - can loosen mucous plugs in CF patients. Also used as an antidote for acetaminophen overdose.
N-acetylcysteine
Antitussive (antagonizes NMDA glutamate receptors). Synthetic codeine codeine analog. Has mild opioid effect when used in excess. Mild abuse potential
Dextromethorphan
Given for dextromethorphan overdose.
Naloxone
Sympathomimetic alpha-agonistic nonprescription nasal decongestants
Pseudoephedrine, phenylephrine
Relaxes bronchial smooth muscle (beta2–> increased cAMP). use during acute asthma exacerbation.
Albuterol
long-acting b2 agonists given for asthma prophylaxis
Salmeterol, formoterol
Likely causes bronchodilation by inhibiting phosphodiesterase –> increased cAMP levels due to decreased cAMP hydrolysis.
Theophylline (methylxanthine)
Competitive block of muscarinic receptors, preventing bronchoconstriction
Ipratropium
Long-acting muscarinic antagonist
Tiotropium
Inhibit the synthesis of virtually all cytokines. Inactivate NF-kappaB, the transcription factor that induces the production of TNF-alpha and other inflammatory agents. 1st line therapy for chronic asthma
Beclomethasone, fluticasone (corticosteroids)
Block leukotriene receptors, esp good for ASA-induced asthma
Montelukast, zafirlukast (antileukotrienes)
5-lipoxygenase pathway inhibitor. Blocks conversion of arachidonic acid to leukotrienes.
Zileuton
Monoclonal anti-IgE antibody. Binds mostly unbound serum IgE and blocks binding to Fc-epsilon-RI. Used in allergic asthma resistant to inhaled steroids and long-acting beta-2 agonists
Omalizumab
Muscarinic receptor agonist. Used in bronchial provocation challenge to help diagnose asthma.
Methacholine
Used to treat pulmonary arterial HTN. Competitively antagonizes endothelin-1 receptors, decreased pulmonary vascular resistance.
Bosentan
1st generation H1 blockers (3)
diphenhydramine, dimenhydrinate, chlorpheniramine
2nd generation H1 blockers (4)
loratadine, fexofenadine, desloratadine, cetirizine
Adverse effects of salmeterol & formoterol
tremor, arrhythmia
Adverse effects of theophylline (methylxanthine)
tachyarrhythmia, seizure (narrow TI)p metabolized by cytochrome P450; blocks actions of adenosine
tx: acute asthma exacerbation
albuterol
tx: chronic asthma
inhaled corticosteroids (beclomethasone, fluticasone)