Antihistamines and Respiratory Infections

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Questions and Answers

What should a breast-feeding mother using codeine monitor in her infant?

Frequency of urination

Increased appetite

Behavioral changes such as drowsiness (correct)

Digestive changes

What is the recommendation regarding the dosage of codeine for a breastfeeding mother?

Take codeine only during night hours

Avoid using codeine entirely during breastfeeding

Prescribe the smallest dose for the shortest time possible (correct)

Use the largest effective dose for a long duration

Why is it advised to avoid using antitussives during pregnancy?

They cause excessive weight gain

They are too costly

They are known to be ineffective (correct)

They interact negatively with prenatal vitamins

What category is guaifenesin in during pregnancy?

Category C Signup and view all the answers

What is the primary reason for using decongestants cautiously during pregnancy?

They are not considered first-line treatments Signup and view all the answers

What is the recommended duration for the use of decongestants in pregnancy?

Less than three days Signup and view all the answers

What is the potential concern regarding the use of guaifenesin in the first trimester?

It may be associated with birth defects Signup and view all the answers

Which of the following is true regarding infant exposure to maternal medications?

Maternal intake often results in smaller infant exposure than direct medication Signup and view all the answers

What effect do antihistamines have on intraocular pressure in patients with narrow-angle glaucoma?

They increase intraocular pressure. Signup and view all the answers

Why do second-generation antihistamines generally have fewer sedative effects compared to first-generation antihistamines?

They cannot cross the blood-brain barrier. Signup and view all the answers

What is a common anticholinergic effect of antihistamines in the elderly?

Impaired learning and memory. Signup and view all the answers

What adverse effects might occur when using second-generation antihistamines?

Drowsiness and fatigue. Signup and view all the answers

What is the primary mechanism by which first-generation antihistamines induce sedation?

They cross the blood-brain barrier and slow neuronal firing. Signup and view all the answers

What is a notable exception among the second-generation antihistamines regarding sedation?

Cetirizine. Signup and view all the answers

What time frame is generally required to reach a steady-state when using second-generation antihistamines?

1-3 days. Signup and view all the answers

What condition might be exacerbated by the use of antihistamines in patients with benign prostatic hypertrophy?

Decreased urine flow. Signup and view all the answers

What is the primary action of intranasal antihistamines in treating allergic rhinitis?

To inhibit histamine release Signup and view all the answers

Which combination is recommended for the treatment of moderate to severe nasal symptoms of seasonal allergic rhinitis?

Intranasal corticosteroids and intranasal antihistamines Signup and view all the answers

What adverse effects may intranasal antihistamines cause?

Sedation and bitter taste Signup and view all the answers

How do leukotriene modifiers alleviate symptoms of allergic rhinitis?

By reducing bronchoconstriction and inflammation Signup and view all the answers

What is a significant characteristic of montelukast (Singulair) regarding its usage?

It has a Black Box Warning for several psychological side effects. Signup and view all the answers

When is the optimal time to take leukotriene modifiers for their maximum effectiveness?

At bedtime Signup and view all the answers

What distinguishes leukotriene modifiers from intranasal corticosteroids in terms of effectiveness?

Leukotriene modifiers require longer to see benefits and are less effective alone. Signup and view all the answers

What is the main source of issues associated with the use of montelukast in patients?

Concerns over psychological side effects Signup and view all the answers

What is the recommended duration for using oxymetazoline nasal spray consecutively?

Three days Signup and view all the answers

What potential risk is associated with the use of pseudoephedrine during the first trimester of pregnancy?

Gastroschisis Signup and view all the answers

What effect can pseudoephedrine have on lactation?

Decrease milk production Signup and view all the answers

Which organization is NOT one of the two main bodies that provide guidelines for asthma treatment recommendations?

European Respiratory Society (ERS) Signup and view all the answers

What is a common cautioned effect of pseudoephedrine related to its use during breastfeeding?

Occasional irritability Signup and view all the answers

Which of the following medications has an unknown safety profile during lactation?

Oxymetazoline Signup and view all the answers

What should be considered before using oral systemic decongestants like pseudoephedrine?

If nasal oxymetazoline would be a safer option Signup and view all the answers

Which of the following is a possible adverse effect of phenylephrine based on mixed data?

Fetal hypoxia Signup and view all the answers

What is the main reason to assess risk versus benefits prior to prescribing medication for patients with a history of depression?

To monitor for potential suicidal behavior Signup and view all the answers

Which statement accurately describes the effectiveness of continuous antibiotic use in older studies versus recent studies regarding COPD exacerbations?

Recent studies indicate that continuous use may reduce exacerbation frequency. Signup and view all the answers

What is one of the advantages of delivering medications through inhalation?

It enhances therapeutic effects by targeting the site of action. Signup and view all the answers

What is a recommended practice when using metered-dose inhalers (MDIs)?

Use a spacer to improve medication delivery. Signup and view all the answers

What is a key difference between dry powdered inhalers (DPIs) and metered-dose inhalers (MDIs)?

DPIs do not require spacers for use. Signup and view all the answers

What delivery method can result in less drug deposition in the oropharynx when treating COPD?

Nebulizers Signup and view all the answers

Why are spacers recommended for use with metered-dose inhalers?

They improve drug delivery to the lungs. Signup and view all the answers

How much of the drug delivered by a metered-dose inhaler typically reaches the lungs?

Approximately 10% Signup and view all the answers

What is the primary purpose of nicotine replacement therapy (NRT)?

To relieve cravings and reduce withdrawal symptoms Signup and view all the answers

Which of the following is NOT a contraindication for using nicotine replacement therapy?

Mild hypertension Signup and view all the answers

Which of the following statements regarding the effectiveness of different types of NRT is accurate?

All types of NRT have comparable effectiveness in smoking cessation. Signup and view all the answers

What should be done if a patient experiences irregular heartbeat while using NRT?

Discontinue use of the NRT Signup and view all the answers

What is a common adverse effect associated with NRT gum?

Hypersalivation and mouth soreness Signup and view all the answers

Which patient group should use nicotine replacement therapy with caution?

Patients with esophagitis or active gastric ulcers Signup and view all the answers

What benefit does nicotine replacement therapy provide to those trying to quit smoking?

It can delay or lessen weight gain Signup and view all the answers

The average smoker attempts to quit how many times before successfully quitting?

Five times Signup and view all the answers

Study Notes

Allergic Rhinitis, Cough, and Upper Respiratory Infection (URI)

Antihistamines (H1 Receptor Antagonists): Divided into 1st and 2nd generation. 1st generation are older, sedating, and have a more rapid onset (15-30 minutes), but tolerance develops quickly. 2nd generation are less sedating and have a slower onset (1-2.5 hours), and have a longer half-life. Some exceptions exist, such as cetirizine (Zyrtec) which might have slight sedation.
Mechanism of Action: Block histamine receptors, reducing effects of histamine.
Anticholinergic Effects: Secondary effect of most antihistamines, drying the mucous membranes. Can cause drowsiness, somnolence, fatigue, cognitive decline, psychomotor effects, loss of coordination, sinus tachycardia, dry skin, dry mucous membranes, dilated pupils, constipation, ileus, urinary retention, and agitated delirium
1st Generation Antihistamines: faster onset of action, more sedating, quicker tolerance or drug failure, and interact with anti-fungals
2nd Generation Antihistamines: less sedating, slower onset of action, more appropriate for patients requiring non-sedating effects, do not cross the blood-brain barrier as actively, and less impact on QT interval.
Side Effects: Sedation, drowsiness, headache, dry mouth, dyspepsia, nausea, fatigue. Some 1st generation antihistamines have a paradoxical reaction in children; instead of sedation, they may exhibit hyperactivity.
Cautions: Narrow-angle glaucoma, benign prostatic hypertrophy, elderly patients
Nasal Decongestants: Vasoconstrictors, relieve nasal congestion by constricting blood vessels. Topical or oral. Over-the-counter (OTC).
Oral Decongestants: Activate alpha-1-adrenergic receptors. Potentially more significant side effects.
Antitussives: Suppress cough, e.g., codeine, dextromethorphan, diphenhydramine.
Expectorants: Fluid thinners, e.g., guaifenesin. Encourage increased fluid intake. Promote productive cough
Nasal Corticosteroids: Effective in preventing symptoms. Daily use needed. Offer antihistamine for first five days of use due to time needed to build up an effective barrier of these steroids.
Intranasal Cromolyn: Less effective than corticosteroids, but safer option in certain cases.

Cough and Cold Medications

Combination Products: Usually contain acetaminophen or ibuprofen, decongestant, antihistamine, and/or cough suppressant/expectorant.
Education Crucial: Educate patients on risks of too much acetaminophen (liver damage), oral decongestants (hypertension), antihistamines (sedation), and alcohol (additive sedation/cognitive impacts).
OTC Products: Important to educate and verify patients understand ingredients/dosages of OTC products. Prioritize use of single agent products.

Asthma and COPD

Guidelines: Global Initiative for Asthma (GINA) and National Heart, Lung, and Blood Institute (NHLBI) guidelines
Approach: Two-pronged approach.
- Relievers (Bronchodilators): Rapid relief of symptoms e.g., short-acting beta-2 agonists (SABAs).
- Controllers: Prevent symptoms by reducing inflammation e.g., inhaled corticosteroids (ICS).
Beta-2 Agonists: Promote smooth muscle relaxation, e.g., albuterol (rescue medication).
Leukotriene Modifiers: Inhibit leukotrienes, e.g., montelukast (Singulair). Reduce inflammation and airway narrowing. Important for long-term control
Monoclonal Antibodies: Used in severe cases, e.g., omalizumab (Xolair).
Inhaled Corticosteroids: Reduce inflammation in the lungs

Medications for Smoking Cessation

Nicotine Replacement Therapy (NRTs): Gum, patch, nasal spray, lozenge. Relieve cravings and withdrawal symptoms.
Varenicline (Chantix): Partial nicotinic agonist. Reduces withdrawal symptoms and cravings
Bupropion (Zyban): Reduces cravings and withdrawal symptoms; originally an antidepressant. Not recommended with MAOIs.

Pregnancy and Breastfeeding

Caution: Consult with healthcare provider for specific guidance.

Other Considerations

Education: Emphasize proper use of inhalers. Educate patients on the potential side effects of all medications, particularly combinations. Emphasize risk versus benefits of various medications.

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Description

This quiz explores the role of antihistamines in treating allergic rhinitis and upper respiratory infections. It covers mechanisms of action, differences between 1st and 2nd generation antihistamines, and their side effects. Test your knowledge on how these medications work and their effects on the body.