Respiratory Pharmacology

Respiratory Pharmacology Exam I

Antihistamines

H1 Antagonists1st Generation ZZZZ… • Overview • Penetrate CNS => High Sedative • Anticholinergic = • Antiemetic • Cognitive decline in the ELDERLY • Diphenhydramine (Benadryl) • Clinical Use: (Topical, Oral, IV, IM) • Motion sickness • Antitussive • Night time Sleep Aid • Topical Antipruritic • Type I:IgE-mediated hypersensitivity rxns • Topical w/Maalox canker sores in children

H1 Antagonists1st Generation • Doxylamine • Clinical Use: OTC • Night time Sleep Aid • Dimenhydrinate (Dramamine) • Clinical Use: OTC • Nausea & Vomiting • Dizzyness & Vertigo • Meclizine (Antivert) – Long-acting => 12-24hrs • Clinical Use: • Motion sickness

H1 Antagonists1st Generation • Hydroxyzine • Clinical Use: • Motion sickness + PRURITUS • Antianxiety • Sedation Pre/post-op • Promethazine • Clinical Use: • Motion sickness • Antianxiety • Sedation Pre/post-op • Type I:IgE-mediated hypersensitivies (Allergic Rhinitis) • Antiemetic = Prevent N & V assoc. w/ General Anesthetics • Block DA receptors in Chemoreceptor Trigger Zone (CTZ) • Caution: Can ↓ Seizure Threshold

H1 Antagonists1st Generation • Chloropheniramine • Brompheniramine • Available only w/ other ingredients: • Pseudoephedrine, APAP, dextromethorphan • Cryproheptadine • SN: “Best to treatITCHING” • SE: • Weight Gain • Block 5-HT2 receptors

H1 Antagonists1st Generation (Ophthalmics) Allergic Conjunctivitis • Ophthalmics • Used forITCHING w/ • SE:Sedation and Anti-SLUD • Caution: According to Dr. Walters, “DUH!” • w/ other Sedating Drugs • Narrow Angle Glaucoma • Azelastine (Nasal spray) • Olopatadine • H1 antagonist InhibitsDegranulation +

H1 Antagonists2st Generation Hello NURSE! • Overview • Does NOT penetrate CNS=>Poorly/NOTSedative • NOAnti-SLUD activity! • NOAntiemetic activity! • Fexofenadine (Allegra) • Cetirizine (Zyrtec) – Long-acting => 12-24hrs • Active metabolite of Hydroxyzine • Slightly Sedative

H1 Antagonists2st Generation • Loratadine (Claritin) • SE:↑ Appetite =>Weight Gain • Desloratadine (Clarinex) • Isomer of Loratadine • β Agonist, Cromolyn, & Nedocromil • All have antihistamine activity by: • BlockingDegranulation of MAST CELLS!

H2 Antagonists • Overview • MOA: • Blocks H2 component of Allergic Response • InhibitsGASTRIC ACID secretion • Clinical Use: • Duodenal and gastricULCERS • SE: • Headaches • Diarrhea / Constipation • Drowsiness • CNS – rare but possible in the elderly

H2 Antagonists • Cimetidine (Tagamet) - Oral & IV/IM • BINDS tocytochrome P450 • Significant inhibitorofRx metabolism • Side Effects • ↑ Estradiollevels in men (↓ P450 activity) • ↑ Prolactin=> GYNECOMASTIA • Caution in tx of ZES • TUMOR of Pancreatic Islets = ↑↑↑ Acid secretion • Inhibits 5 α reductase (↓ DHT) • Inhibits Binding of DHT • Impotence & ↓Libido Caution: Weakly acidic = ↑Rx absorption Only in High Doses

H2 Antagonists • Ranitidine (Zantac) - Oral & IV/IM • Famotidine (Pepcid) OTC (except IV) • Pepcid Complete • Famotidine + CaCO3 + Magnesium Hydroxide • Nizatidine - Oral

Nasal Decongestants • Phenylephrine • Clinical Use: • IVfor SHOCK • Systemic↑BP • IVfor Supraventricular Tachycardia • Baro-reflex=>↓HR • Mydriatic = pupillary dilation • Contracts dilator muscles • Added to Local Anesthetics • Vasoconstriction– keepanesthetic local

Nasal Decongestants • Oxymetazoline • Clinical Use: Ocular decongestant • Available in a drop or spray • EXCEPTION: α2 agonist • Pseudoephedrine (Sudafed) • Available in tablets, oral liquid, & pediatricdrops

Expectorant • Guaifenesin (Robitussin) • MOA: • Irritant of the lining of the airway • ↑ Secretions=> Helps to dilute and break up FLEM • ↓ VISCOITY • ↓ Surface Tension • RobitussinDM • Dextromophorphan + guaifenesin

Respiratory Pharmacology