Pharmacology: H1RAs vs H2RAs

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Questions and Answers

Under what circumstances should cough suppression be used?

For productive cough to enhance secretion clearance

For any type of cough to promote rest

Whenever a patient experiences severe coughing fits

Only for nonproductive cough or at night when needed (correct)

What distinguishes antitussives from expectorants?

Expectorants suppress the cough reflex.

Antitussives are cough suppressants for nonproductive coughs. (correct)

Antitussives are typically used for productive coughs.

Expectorants are used primarily for dry throat relief.

What is the primary role of intranasal corticosteroids?

To relieve acute symptoms by blocking histamine

To directly treat cough caused by infections

To enhance mucus production for easier cough clearance

To prevent and decrease symptoms by lowering inflammatory mediators (correct)

What is a significant benefit of nasal antihistamines?

They have a rapid onset and reduce airway hyperreactivity. Signup and view all the answers

How do leukotriene modifiers work in allergy treatment?

By decreasing smooth muscle contraction and inflammatory response Signup and view all the answers

What is the Black Box Warning associated with Montelukast (Singulair)?

Risk of mood changes and suicidal ideation Signup and view all the answers

Which class of drugs is typically not appropriate for young children under 2 years old?

Opioids for cough suppression Signup and view all the answers

What is the role of 2nd generation oral antihistamines?

To relieve acute allergy symptoms by blocking histamine action Signup and view all the answers

Which intranasal corticosteroid is categorized as safe during pregnancy?

Budesonide Signup and view all the answers

What is the main concern regarding chlorpheniramine when used in large doses during breastfeeding?

Infant sedation and reduced milk supply Signup and view all the answers

Doxylamine is known for its safety in which context?

Pregnancy only Signup and view all the answers

What precaution should be taken when administering codeine to breastfeeding mothers?

Monitor for sedation and respiratory difficulties Signup and view all the answers

Which decongestant is associated with an increased risk of gastroschisis when used in the first trimester?

Pseudoephedrine Signup and view all the answers

Which of the following medications should be avoided during lactation due to safety concerns?

Doxylamine Signup and view all the answers

What is the recommended first-line antihistamine for breastfeeding mothers?

Cetirizine Signup and view all the answers

What is a potential adverse effect of using Oxymetazoline for more than three days?

Rebound congestion Signup and view all the answers

Which antitussive medication has questionable effectiveness and potential risks in the first trimester?

Guaifenesin Signup and view all the answers

What should be considered first when treating acute congestive episodes in pregnancy?

Intranasal saline sprays Signup and view all the answers

What are the potential side effects associated with the prolonged use of inhaled corticosteroids?

Risk of bone loss Signup and view all the answers

Why is it important to taper off glucocorticoids gradually?

To prevent adrenal crisis Signup and view all the answers

What is a major concern regarding the use of inhaled corticosteroids in children?

Reduction in growth velocity Signup and view all the answers

How do mast cell stabilizers function in asthma treatment?

They block the release of certain inflammatory mediators Signup and view all the answers

Which of the following statements correctly describes the role of SABAs in asthma treatment?

They provide quick relief from symptoms Signup and view all the answers

What does a narrow therapeutic index indicate regarding medication use?

Higher risk for toxicity Signup and view all the answers

What caution should be taken when using inhaled corticosteroids in patients with a history of eye diseases?

Routine eye exams are advised, but they are safe Signup and view all the answers

What is a common adverse effect of monoclonal antibodies in asthma treatment?

Risk of anaphylaxis Signup and view all the answers

What is a primary use of oral corticosteroids in COPD management during acute exacerbations?

To reduce treatment failure and improve lung function Signup and view all the answers

Which of the following is a potential side effect of Phosphodiesterase-4 (PDE4) inhibitors?

Hepatotoxicity and neuropsychiatric effects Signup and view all the answers

What role do antibiotics play in the management of COPD according to recent studies?

They may decrease exacerbation rates due to their anti-inflammatory properties. Signup and view all the answers

What is a necessary consideration when prescribing mucolytics to COPD patients?

They may not be effective in patients already on ICS treatment. Signup and view all the answers

Which patients are recommended to consider the use of Phosphodiesterase-4 (PDE4) inhibitors?

Patients with chronic bronchitis on maximal inhaled therapy. Signup and view all the answers

What is a significant disadvantage of using metered-dose inhalers (MDIs)?

Deliver only about 10% of the drug to the lungs Signup and view all the answers

What is the primary reason why long-acting beta2 agonists (LABAs) are used in combination with inhaled corticosteroids?

They pose an increased risk of asthma-related deaths if used alone Signup and view all the answers

Which medication type is classified as a controller in asthma management?

Inhaled corticosteroids (ICS) Signup and view all the answers

Why might patients with diabetes mellitus need to be cautious with beta2 agonists?

They can potentially increase serum glucose levels Signup and view all the answers

What is a notable advantage of using dry powder inhalers (DPIs) compared to metered-dose inhalers (MDIs)?

They deliver approximately 20% of the drug to the lungs Signup and view all the answers

In what way are oral glucocorticoids typically administered during asthma exacerbations?

In short bursts to provide immediate coverage Signup and view all the answers

What are the main roles of inhaled corticosteroids in asthma treatment?

They decrease inflammation and control symptoms Signup and view all the answers

Which type of device does not require hand-breath coordination for administration?

Nebulizers Signup and view all the answers

What is one of the potential serious adverse effects of Varenicline?

Increased risk for neuropsychiatric effects Signup and view all the answers

What is the primary mechanism of action of Bupropion SR (Zyban) in smoking cessation?

Inhibits neuronal uptake of norepinephrine and dopamine Signup and view all the answers

Which statement regarding the use of Bupropion during pregnancy is correct?

Bupropion and its metabolites cross the placenta. Signup and view all the answers

What is a notable side effect of Varenicline related to alcohol?

Enhancement of alcohol's sedative effects Signup and view all the answers

Which of the following is a Black Box Warning associated with Bupropion SR (Zyban)?

Suicidal thoughts and behavior in young individuals Signup and view all the answers

Study Notes

H1RAs vs H2RAs

H1RAs bind selectively to H1 receptors, blocking histamine actions at these sites
H1RAs have low receptor specificity, interacting with both peripheral and central histamine receptors
H1RAs readily cross the blood-brain barrier
H2RAs selectively block H2 receptor sites, reducing gastric acid secretion
H2RAs are useful for treating gastric ulcers and GERD (e.g., cimetidine, famotidine)

Histamine Receptor Antagonist Generations

First-generation H1 receptor antagonists cross the blood-brain barrier, causing sedation
Second-generation H1 receptor antagonists do not significantly cross the blood-brain barrier, avoiding sedation (except for cetirizine/Zyrtec)

Anticholinergic Side Effects

Sinus tachycardia, dry skin, dry mucous membranes, dilated pupils, constipation, ileus, urinary retention, and agitated delirium
Elderly, glaucoma, and BPH patients should avoid anticholinergic drugs

Anticholinergic Drugs

Oral decongestants (e.g., pseudoephedrine)
First-generation antihistamines (e.g., diphenhydramine)
Second-generation antihistamines (e.g., cetirizine, fexofenadine)

Cough and Cold Medicine Combination

Choose single-agent products to reduce overdose risk
Avoid unnecessary medications
Easier to identify allergens

Nasal Decongestants

Potential side effects: sneezing, nasal dryness, rebound nasal congestion
Not recommended for more than 3 days consecutively due to rebound congestion risk
Patients with hypertension, arrhythmias, and sleep problems should avoid oral decongestants

Drug Therapy for Cough

Use cough suppression for non-productive coughs or nighttime use
Avoid opioids in patients with substance abuse or COPD history
OTC cough medications should not be used in those under 2

Antitussives vs Expectorants

Antitussives suppress cough (nonproductive)
Expectorants thin secretions (productive cough)

Asthma Controllers and Relievers

Controllers: Prevent symptoms (intranasal corticosteroids, leukotriene modifiers)
Relievers: Relieve acute symptoms (2nd generation oral antihistamines, intranasal antihistamines, ocular antihistamines)

Nasal Antihistamines

Benefits: rapid onset, reduce airway hyperreactivity
Potential Side effects: sedation (less than oral), bitter taste

Leukotriene Modifiers

Decrease smooth muscle contraction, blood vessel permeability, and inflammatory response
Most effective when taken at bedtime

Black Box Warning for Leukotriene Modifiers

Montelukast carries a warning for agitation, aggression, anxiety, dream abnormalities, hallucinations, depression, insomnia, irritability, restlessness, suicidal ideation, behavior (including suicide), and tremor.

Asthma Treatment During Pregnancy and Lactation

First-line treatments: rest, hydration, a diet high in fruits and vegetables, saline nasal spray
Intranasal corticosteroids (e.g., Budesonide) are most effective and deemed safe in pregnancy
Antihistamines and some other medications (e.g., Chlorpheniramine, Diphenhydramine) are considered safe in most breastfeeding cases

Inhaled Medication Delivery Methods

Metered-dose inhalers (MDIs): Small hand-held devices; require hand-breath coordination; ~10% of drug reaches lungs
Dry-powder inhalers (DPIs): Deliver drugs as a dry powder to the lungs; do not require hand-breath coordination; ~20% of drug reaches lungs
Nebulizers: Machines that convert drug solution into a fine mist; less drug deposition in the mouth, increased delivery to the lungs; hand-breath coordination is not necessary

Inhaled Corticosteroids

Effective in controlling asthma and suppressing inflammation
Potential side effects: bone loss (avoid with calcium, vitamin D, and exercise), increased intraocular pressure (routine eye exams), oral fungal infections (rinse mouth), and slowed growth

Mast Cell Stabilizers

Prevent bronchoconstriction by blocking histamine and SRS-A release from sensitized mast cells
Anti-inflammatory agents

SABA, LABA, SAMA, and LAMA Role in Asthma Management

SABAs: quick-relief (short-acting beta-agonists)
LABAs: long-acting bronchodilators (maintenance)
SAMAs: quick-relief (short-acting muscarinic antagonists)
LAMAs: long-acting bronchodilators (maintenance)

Narrow Therapeutic Index

Risk of toxicity is high because the therapeutic range is very narrow.

Monoclonal Antibodies in Asthma Treatment

Anti-IgE antibodies (e.g., omalizumab) limit allergen-induced histamine, leukotriene, and other mediator release.
Interleukin-5 receptor antagonists reduce eosinophil production
Associated risks: anaphylaxis, malignancy, neoplasms, immunogenicity,

COPD Treatment Considerations

Anticholinergics (i.e., SAMAs and LAMAs): Long-acting bronchodilators are beneficial for moderate-severe COPD patients

Oral & Inhaled Corticosteroids in COPD

Inhaled corticosteroids decrease inflammation
Oral corticosteroids are used for exacerbations
Both reduce exacerbations and improve lung function

NRT (Nicotine Replacement Therapy)

Gum, Lozenge, Patch: Advantages: Serves as a tobacco alternative, may delay weight gain, easy titration
Gum, Lozenge, Patch: Disadvantages: frequent dosing, may cause mouth/tooth issues (gum) and/or swallowing issues, inconsistent nicotine delivery (lozenge), potential for skin reaction (patch), and need to adhere to use schedule

Varenicline Mechanism of Action

Blocks nicotine binding to dopaminergic receptors, reducing cravings and withdrawal symptoms

Varenicline Potential Side Effects

Potential for increased risk of suicidal thoughts, depression, and other psychiatric events

Bupropion (Zyban) Mechanism of Action

Inhibits dopamine/norepinephrine uptake

Bupropion Potential Side Effects

Increased risk of suicidal thoughts, mood changes, hallucinations, panic, depression, restlessness, insomnia, and anxiety

Smoking Cessation During Pregnancy

Bupropion and metabolites cross the placenta.
Limited data on long-term effects

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Description

This quiz covers the key differences between H1 receptor antagonists (H1RAs) and H2 receptor antagonists (H2RAs) in pharmacology. You will explore their mechanisms, uses, and side effects, including the impact of anticholinergic drugs on patients. Test your understanding of these important drug classes to enhance your knowledge of pharmacological treatments.