Respiratory Drugs

3 classes of autacoids

Histamine, Serotonin, Eicosanoids

nitrogenous compound involved in:
immune responses, inflammatory response, gut regulation, neurotransmitter, released by mast cells

Histamine

Receptor in smooth muscle, endothelium, brain

H1

Gq, increase IP3, DAG

H1

Allergic reactions (dermatitis, rhinitis, conjunctivitis) proinflammatory

H1

Gastric mucosa, cardiac muscle, mast cells, brain

H2

Gs, increase cAMP

H2

presynaptic: brain, histaminergic neurons

H3

Gi, decrease cAMP

H3

inhibits histamine release and synthesis

H3

eosinophils, neutrophils, CD4 T cells

H4

stimulates chemotaxis of eosinophils and mast cells, potential target in allergic rhinitis and asthma

H4

reduce or block the actions of histamine by reversible competitive binding to the H1 receptor

H1 receptor anatagonist

negligible potency at H2 and H3 receptors

H1 receptor anatagonist

all have sedative effects, can treat N/V, some anticholinergic side effects (urinary retention, blurred vision), some are local anesthetics (procaine, lidocaine, promethazine)

First generation anti-histamines

Promethazine (Phenergan)

first generation anti-histamine

Diphenhydramine (Benadryl)

first generation anti-histamine

Chlorpheniramine (Chlor-trimeton)

first generation anti-histamine

Clemastine (Travist)

first generation anti-histamine

Dimenhydrinate (Dramamine)

first generation anti-histamine

hydroxyzine (atarax)

first generation anti-histamine

meclizine (antivert)

firs generation anti-histamine

Do not have anti-emetic properties

2nd generation anti-histamine

mainly used to trx allergies (allergic rhinitis and chronic uticaria)

2nd generation anti-histamine

do not produce significant sedation

2nd generation anti-histamine

fewer anti-cholinergic side effects

2nd generation anti-histamine

Fexofenadine (allegra)

2nd generation anti-histamine

Loratadine (claritin)

2nd generation anti-histamine

Desloratadine (clarinex)

2nd generation anti-histamine

cetirizine (zyrtec)

2nd generation anti-histamine

azelastine (astelin)

2nd generation anti-histamine
(nasal spray)

olopatadine (patanase)

2nd generation anti-histamine
(nasal spray)

autacoid, NT produced by platelets, gut cells, neurons

Serotonin

metabolized by MAO

serotonin

many 5-HT receptors identified

serotonin

present in nervous system, respiratory system, cardiovascular system, GI, skeletal muscles

serotonin

stimulant of pain and itch

serotonin

triggers vomiting

serotonin

contraction of smooth muscles (GI)

serotonin

vasoconstrictor

serotonin

bradycardia and hypotension (vagal nerve)

serotonin

neuroendocrine control (sleep, temp, appetite)

serotonin

Bind to and activate 5-HT receptors, like serotonin

5-HT agonist

Sumatriptian (Imitrex)

5-HT agonist (migraines)

Eletriptan (Relpax)

5-HT agonist (migraines)

Buspirone (Buspar)

5-HT agonist (anxiolytic)

Tegaserod (Zelnorm)

5-HT agonist (IBS- limited use)

Clozapine (Clozaril)

5-HT antagonist (anti-psychotic)

Ondansetron (Zofran)

5-HT antagonist (anti-emetic)

Derived from arachidonic acid

eicosanoids

2 main categories of eicosanoids

Prostaglandins and Leukotrienes

Alprostadil (Caveriect, Muse)

synthetic PGE1
maintain patency of ductus arteriosus in neonates
tx erectile dysfunction

Misoprostol (Cytotec)

synthetic PGE1
prevents peptic ulcer
termination of pregnancy (in combo with RU-486)

Dinoprostone (Cervidil)

synthetic PGE2 and PGF2
produce cervical ripening

Carboprost (Hemabate)

synthetic PGE2 and PGF2
control post-partum bleeding

Epoprostenol (Flolan)

Prostaglandin I2 (Prostacyclin)
treat pulmonary arterial hypertension

produced by leukocytes

leukotrienes

pathway associated with asthma, anaphylactic shock, cardiovascular disease

leukotrienes

Leukotriene D4 causes: 3 respones

bronchoconstriction, mucosal edema, mucus hypersecretion

Drugs that inhibit leukotrienes:

LTD4 receptor blockers
LOX inhibitors (lipooxygenase)

LTD4 receptor blockers: 2

Zafirlukast (accolate)
montelukast (singulair)

LOX inhibitors: 1

Ziluton (Zyflo)

potential liver toxicity
sustained release tablet 2/day
must be careful; inhibits CYP450 enzymes. Be careful with STATINS

Ziluton (Zyflo)

chronic inflammatory disease of the airways

asthma

hyperresponsiveness

asthma

stabilizes mast cells

cromolyn, nedocromil,
IgE Abs- Omalizumab

only valuable for prophylactic use to tx asthma

cromolyn, nedocromil
(sprays or eye drops as well for rhinoconjunctivitis)

don't effect airway smooth muscle tone

cromolyn, nedocromil

inhaled fine powder

cromolyn

metered dose inhaler

nedocromil

Anti IgE antibody

Omalizumab (xolair)

giving in addition to existing long term inhaled steroid to tx asthma

Omalizumab (xolair)

major toxicity- hypersensitivity and anaphylaxis

omalizumab (xolair)
observe for at least 2 hrs and carry epinephrine

block release of inflammatory mediators

glucocorticoids) prednisone, methylprednisone
LIs- Montelukast, Zafirlukast

block production of cytokines

glucocorticoids) prednisone, methylprednisone

Block mast cell migration

glucocorticoids) prednisone, methylprednisone

Do NOT directly relax bronchial muscle but DO reduce bronchial reactivity

glucocorticoids) prednisone, methylprednisone

Improve pulmonary function
Long-term treatment to prevent asthma attacks

glucocorticoids) prednisone, methylprednisone

inhaled glucocorticoids (5)

FLUTICASONE (FLOVENT�)
BECLOMETHASONE (VANCERIL�)
TRIAMCINOLONE (AZMACORT�)
FUNISOLIDE (AEROBID�)
BUDESONIDE (PULMICORT�)

increase lipolysis, redistribution of fat

glucocorticoids

water retention

glucocorticoids

decrease Ca absorption from gut

glucocorticoids

stimulate gastric acid production

glucocorticoids

mood changes

glucocorticoids

promote bronchodilation

methylxanthines- theophylline
SABA- albuterol, Epi, terbutaline
LABA- salmeterol, Formoterol
Anticholinergics- Ipratropium bromide

Inhibits phosphodiesterase - enzyme that degrades cAMP (??cAMP levels)

methylxanthene- theophylline (Elixophyllin)
Aminophylline
main use COPD

narrow therapeutic window, N/V, half-life varies, metabolized in liver (DDI), 2nd line drugs from chronic asthma

Bronchodilators
methylxanthene- theophylline (Elixophyllin)
Aminophylline

have potential for tremor, tachycardia, nausea

SABA
Epinephrine
Albuterol (Proventil�)
Terbutaline (Brethine�)

LABAs with ICS

Budesonide/formoterol (Symbicort�)
Fluticasone/salmeterol (Advair Diskus�, Advair HFA�)
Mometasone/formoterol (Dulera�)

Anticholinergics
Acts as a bronchodilator

Aclidinium bromide (Tudorza Pressair �)
Ipratropium (Atrovent �)
Tiotropium (Spirvia �)

Increase goblet cells, decrease in ciliated epithelial cells, decrease in ME clearance

COPD

Blocks constricting effects of parasympathetic nerve stimulation
Mainly used for COPD

Bronchodilators: Muscarinic Receptor Antagonists
IPRATROPIUM (ATROVENT�)
Inhaled agent
Few side effects, poor absorption
Mist complexed with SOY (cautious with peanut allergies)
TIOTROPIUM (SPIRIVA�)
No issue with soy or peanut allergy
Increase in stroke

Mainly due to activation of H1 receptors causing vasodilation, congestion, edema and inflammation

Allergic Rhinitis (Allergies)
tx with:
Antihistamines
Inhaled steroid preps
Bronchodilators

ANTI-TUSSIVES - suppress cough

DEXTROMETHORPHAN
CODEINE
BENZONATE (TESSALON�)

EXPECTORANTS - aids in expelling mucus

GUAIFENESIN