changes myocardial contractility
drug family that inhibits break down of cAMP?
effect of having more cAMP?
name of enzyme inhibited?
- more cAMP = bronchodilation
how does methylxanthines' therapeutic window influence their current use?
narrow ther. window --> dangerous
not used much except in severe asthma
"... phylline" drugs are what class of drug?
name the drugs.
caffeine is what class of drug r/t respiratory disorders?
drug used as IV drip in neonates to prevent neonatal apnea
how does smoking (tobacco or weed) interact with methylxanthines?
increases drug elimination, decreases serum concentration
- CNS: restlessness, irritability, anxiety, insomnia, HA
- CV: tachycardia, palpitations, hypotension
- mild diuresis
do methylxanthines cross breast milk?
yes --> baby can have tachycardia or vomit
4 ways that methylxanthines help tx resp disorders
- 1. decrease airway reactivity (bronchodilation)
- 2. inhibit mast cell degeneration (stops release of histamine, leukotrienes)
- 3. stimulate ciliary apparatus (gets rid of secretions)
- 4. in COPD pts - increases sensitivity of resp center to CO2
best respiratory drug used to tx acute attacks
beta agonists - albuterol [Proventil, Ventolin, VoSpire]
*anticholinergics are a possible alternative/addition, but they are much less potent bronchodilators
drug family that promotes production of cAMP?
effect of having more cAMP?
name of enzyme activated
- beta agonists
- increased caMP = bronchodilation
activate adenylate cyclase
resp drug family that is sympathomimetic
(mimic FX of SNS: vasoconstriction, ^HR, etc.)
non-selective beta agonist FX on beta 1 receptors? on beta 2? on alpha?
- beta1: positive chronotropic, positive ionotropic
- beta2: bronchodilation
- alpha: vasoconstriction (in bronchiole vessels, decreasing mucosal edema)
SFX of beta agonists stemming from beta 1 agonism? beta 2? alpha?
SFX unique to Severent?
- beta 1: arrhythmias, tachycardia, palpitations, HA, insomnia
- beta 2: nervousness, restless, tremors
- alpha: insomnia, restlessness, anorexia, tremors, HA, cardiac stimulations
Severent: URI (upper resp infection), angioedema
mast cell inhibitors' (aka mast cell stabilizers) mechanism of action
stabilize cell membranes, preventing release of bronchoconstrictors, like histamine
names of 2 true mast cell inhibitors
- cromolyn [Intal]
- nedocromil [Tilade]
med that is an IgG Ab that binds to IgE receptors sites, stabilizing mast cell cell mebranes; like a mast cell inhibitors, but with different mechanism of action
can mast cell inhibitors/stabilizers be used for acute bronchospasm?
NO! only beta agonists (and possibly anticholinergics) can tx acute bronchospasm
used for prophylaxis only
SFX of mast cell inhibitors
- -cough, sore throat, rhinitis
- -taste changes
- -dizziness and HA
- -pss bronchospasm
"mast cell inhibitor" that is given SC? SFX?
- local injection site irritation
- resp infection
name the 2 anticholinergics used to tx asthma
- ipratropium [Atrovent]
- tiotropium [Spiriva]
drug class that may be combined with beta agonists to provide acute bronchodilation
anticholinergic mechanism of action on resp system
causes local bronchodilation by blocking cholinergic receptors in bronchial smooth muscle, leading to decreased concentration of cGMP
SFX of anticholinergics
ipratropium [Atrovent], tiotropium [Spiriva]
- dry mouth
drug interactions of most respiratory drugs
b/c resp drugs usually absorbed in the lungs (site of action), so limited systemic absorption
why pts are switched from systemic to inhaled corticosteroids asap
- long-term corticosteroid use leads to decreased bone growth
- -osteoporosis in adults
- -stunted bone growth & height in kids
- beclomethasone [Qvar, Beclovent, Vanceril]
- flunisolide [AeroBid]
- triamcinolone [Azmacort]
SFX of inhaled corticosteroids and how to decrease their occurrence
oral fungal infection, sore throat, cough, dry mouth
rinse mouth after using inhaler
interaction of corticosteroids with beta agonists
sensitize bronchial smooth muscl eto be more response to beta agonist stimulation --> corticosteroids aren't brochodilators, but they interact with beta agonists to cause more bronchodilation than beta agonists alone
name 3 leukotriene antagonists and frequency
- zafirlukast [Accolate] - BID
- zileuton [Zyflo] - QID
- monteleukast [Singulair] - qday
what are leukotrienes?
what kinds of cells produce them?
mediators of immune and inflammtory responses; products of arachidonic acid breakdown
- produced by:
- mast cells
administration route of leukotriene antagonists?
how should it be taken in relation to meal times?
take on empty stomach b/c food decreases bioavailability of drug
are leukotrienes used for treating acute asthma attacks?
no! prophylaxis only
how do leukotrienes antagonists indirectly cause bronchodilation?
inhibiting leukotriene's normal FX (via receptor antagonism): promotion of inflammation, edema, and hypersecretion of mucus
zafirlukast [Accolate] drug interactions
- coumadin: increases PT (anticoagulates)
- erythromycin: decreases Accolate
- ASA: ^ Accolate
- also interacts with phenytoin and CBBs, increasing their concentrations
SFX of zafirlukast [Accolate]
- resp infections, esp. in elderly
- Churg-Strauss syndrome: pulmonary infiltrates, eosinophilia, cardiomyopathy
- leukotriene receptor antagonist
- approved for kids 1 y/o+
serious SE of zileuton [Zyflo] and drug contraindications
potential liver damage (increases liver enzymes, need to do baseline labs)
contraindicated in pts with liver disease
which of the 3 leukotriene antagonists inhibits leukotriene synthesis by inhibiting enzyme? (other 2 block leukotriene receptors)
drug used to tx genetic emphysema?
mechanism of action?
alpha 1 proteinase inhibitor: antitrypsin, [Prolastin].
prevents destruction of elastase, enabling lungs to continue expanding and contracting, and keeping alveoli open
name 3 expectorants used to facilitate movement of mucus
- -guafenesin [Robitussin] - first choice expectorant to tx dry, hacking cough
- -iodides (more toxic)
- -terpin hydrate (has lots of ETOH)
what type of tx should follow the administration of a mucolytic?
chest PT, to get rid of the mucus
name of only mucolytic, also used to tx acetaminophen OD. cons to using the med?
- oodles of drug interactions
- rotten egg odor, causing nausea
- bronchospasm, esp. in asthmatic pts