Asthma Medications

Questions and Answers

What type of immune cell is responsible for releasing histamine and other inflammatory chemicals in an allergic reaction?

Mast cells (correct)

T cells

Neutrophils

B cells

What is the primary function of cromolyn sodium in treating asthma?

To block the action of histamine at its receptor sites

To suppress the immune system by binding to free IgE antibodies

To prevent the release of histamine and other inflammatory mediators from mast cells (correct)

To reduce inflammation by inhibiting leukotriene synthesis

Which of the following is a characteristic of a severe systemic allergic reaction?

Localized swelling and redness

Mild itching and sneezing

Anaphylaxis (correct)

All of the above

What is the mechanism by which cromolyn sodium prevents mast cell degranulation?

By blocking calcium influx into mast cells Signup and view all the answers

Which of the following drugs is an antileukotriene that inhibits leukotriene synthesis?

Zileuton Signup and view all the answers

What type of drug is omalizumab?

Monoclonal antibody Signup and view all the answers

How does omalizumab reduce allergic reaction severity?

By binding to free IgE antibodies Signup and view all the answers

What is the primary indication for using cromolyn sodium?

To prevent asthma attacks in people with bronchial asthma Signup and view all the answers

Which of the following is NOT a mechanism of action of anti-asthma drugs?

Stimulating the production of IgE antibodies Signup and view all the answers

What is the role of IgE in allergic reactions?

IgE binds to mast cells and triggers the release of histamine upon re-exposure to the allergen. Signup and view all the answers

Study Notes

Bronchodilator Medications

MDI Formulation: Epinephrine (Epi) delivers 0.22 mg/puff with a duration of action of 1-3 hours.
Racemic Epinephrine: Contains S-2 and is available in SVN 2.25% solution (0.25-0.5 ml, 5-11 mg, given qid).
- Onset: 3-5 minutes, Peak effect: 5-20 minutes, Duration: 0.5-2 hours.
Metaproterenol (Alupent): A β2 agonist available as SVN (0.4-0.6% solution, tid/qid), tablets (10-20 mg, tid/qid), and syrup (10 mg/5 ml).
- Onset: 1-5 minutes, Peak: 60 minutes, Duration: 2-6 hours.
Albuterol (Proventil, Ventolin HFA): Another β2 agonist; SVN 0.5% solution (1.25 or 2.5 mg tid/qid), MDI (90 mcg/puff, 2 puffs tid/qid), tablets (2, 4, 8 mg bid, tid, qid).
- Onset: 15 minutes, Peak: 30-60 minutes, Duration: 5-8 hours.
Pirbuterol (Maxair): MDI formulation (200 mcg/puff, 2 puffs q4h).
- Onset: 5 minutes, Peak: 30 minutes.

Inhaled Anticholinergic Bronchodilators

Ipratropium Bromide: Affects M1, M2, and M3 receptors.
- Dosage: HFA MDI (17 mcg/puff, 2 puffs qid), SVN (0.02% solution, 500 mcg tid/qid), nasal spray (21-42 mcg, 2-4 times daily).
- Onset: 15 minutes, Peak: 1-2 hours, Duration: 4-6 hours.
Ipratropium and Albuterol Combination: Contains 18 mcg/puff of ipratropium and 90 mcg/puff of albuterol.
- Onset: 15 minutes, Peak: 1-2 hours, Duration: 4-6 hours.
Tiotropium Bromide: Highly selective for M3.
- Dosage: SVN (Ipratropium 0.5 mg and albuterol 2.5 mg), DPI (18 mcg/inhalation, 1 inhalation daily).
- Onset: 30 minutes, Peak: 1-3 hours, Duration: 24 hours.

Mechanism of Action

Anticholinergic bronchodilators block acetylcholine at muscarinic receptors in bronchial smooth muscles, reducing mucus production.

Mucolytics and Mucokinetics

Mucolytic Agents: Disrupt chemical bonds in mucoproteins, liquefying mucus for easier removal.
- Examples: N-Acetylcysteine (NAC), Dornase Alpha (Pulmozyme), Hyperosmolar saline.
Expectorants: Increase secretions and decrease mucus viscosity, facilitating easier sputum removal.

Adverse Effects of Mucolytics

Notable side effects include nausea, vomiting, hypersensitivity, rash, fever, and bronchospasm risk in asthmatics.

Corticosteroids (Anti-inflammatories)

Used to treat inflammation, allergies, asthma, and arthritis.
Can be endogenous (produced by the body) or exogenous (prescribed when body levels are low).

Adverse Effects of Corticosteroids

General effects from systemic corticosteroids include immunosuppression, fluid retention, and increased blood sugar.
Specific effects of aerosolized steroids include dysphonia, cough, and risk of local infections.

Non-Steroidal Anti-inflammatory Anti-asthma Drugs

Types:
- Cromolyn-like agents (Mast Cell Stabilizers; e.g., Cromolyn Sodium).
- Antileukotrienes (e.g., Montelukast).
- Monoclonal antibody (e.g., Omalizumab).
Mechanism: Cromolyn Sodium inhibits mast cell degranulation and histamine release. Antileukotrienes block leukotriene receptor activity.

Indications of Cromolyn Sodium

Serves as a prophylactic treatment for asthma, preventing attacks in individuals with bronchial asthma.

Allergy Mechanism

Allergic reactions involve B cells producing IgE antibodies upon initial allergen exposure, which attach to mast cells. During re-exposure, these mast cells release histamine, causing local inflammation and respiratory issues.
Severe systemic reactions are termed anaphylaxis, which can be life-threatening.