Asthma and Anti-histamines Overview

Study Notes

Antihistamines

Examples include chlorpheniramine and dimenhydrinate.
Possess sedative and anti-cholinergic effects.
Provide relief from cough and soothe the throat through pharyngeal demulcents like eucalyptus and menthol.

Asthma Overview

Chronic, reversible inflammatory disease characterized by tracheal and bronchial hyper-responsiveness.
Key components: Airway Obstruction and Airway Inflammation.

Antiasthmatics

Classified into two main categories:
- Anti-inflammatory: Glucocorticoids, mast cell stabilizers.
- Bronchodilators:
  - Beta2 agonists (e.g., salbutamol, adrenaline).
  - Non-selective β-agonists and selective β-agonists.

Bronchodilators

Beta-2 Agonists:
- Short-acting: salbutamol, terbutaline, adrenaline, ephedrine.
- Long-acting: salmeterol, formoterol.
Mechanism of Salbutamol: Relaxes bronchial smooth muscles by stimulating β2-adrenergic receptors.

Salbutamol Administration

Routes: Oral and inhalation.
Indications: Bronchodilation, prophylaxis of exercise-induced bronchospasm.
Initial dosage for management: 200μg via MDI.

Patient Advice for Inhalers

Consult physician before using OTC products.
Avoid discolored solutions, maintain fluid intake (2000–3000 mL/d), and space inhalations by at least one minute.

Hypertension Contributing Factors

Fluid accumulation, increased peripheral resistance, heart rate, and force of contraction.
Lipid degradation and unknown causes can also contribute to hypertension.

Hypertension Classification

Mild: Diastolic BP 95-105 mmHg.
Moderate: Diastolic BP 105-115 mmHg.
Severe: Diastolic BP >115 mmHg.

Hypertension Therapies

Non-Pharmacological:
- Low salt diet, exercise, weight reduction, smoking cessation, reduced alcohol consumption, psychological methods.

Pharmacological Therapy for Hypertension

Classified by regulatory mechanism:
- Diuretics, sympathoplegic agents, direct vasodilators, ACE inhibitors, calcium channel blockers.

Diuretics

Lower BP by depleting sodium and blood volume; reduce BP by 10–15 mmHg.
Types:
- Thiazides: Hydrochlorothiazide, bendrofluazide—appropriate for mild/moderate hypertension.
- Loop Diuretics: Furosemide, bumetanide—indicated for severe hypertension alongside renal or cardiac issues.
- Potassium-Sparing Diuretics: Spironolactone—used with thiazides or loop diuretics to prevent potassium depletion.

Sympathoplegic Agents

Depress sympathetic activity; categorized into:
- Centrally acting agents (e.g., methyldopa).
- Adrenoceptor antagonists (e.g., propranolol, prazosin).
- Adrenergic neuron blocking agents.

Direct Vasodilators

Examples include hydralazine (arterial vasodilator) and nitroprusside (powerful for emergencies).

Antithrombotic Agents

Used in thrombotic disorders; three categories: anticoagulants, antiplatelet drugs, thrombolytics.

Anticoagulants

Prevent new clot formation; examples are heparin and warfarin.
Indicated for thrombophlebitis, DVT, and pulmonary embolism; major adverse effect: bleeding.

Antiplatelet Drugs

Mechanisms include blocking receptor pathways such as Thromboxane A2 (aspirin) and ADP (clopidogrel).
Indicated for reducing MI, stroke, and vascular death risks.

Anemia and Nutrient Requirements

Hematopoiesis requires iron, vitamin B12, and folic acid for erythrocyte production.
Anemia occurs due to deficiency in oxygen-carrying erythrocytes.

Growth Hormone Disorders

GH Excess: Juvenile Acromegaly.
GH Deficiency: Pituitary dwarfism; treated with somatotropin.

Thyroid Hormones and Drugs

Key hormones: Triiodothyronine (T3), Tetraiodothyronine (T4).
Effects include increased metabolic rate, heart rate, and oxygen consumption.

Signs of Thyroid Dysfunction

Hypothyroidism: Decreased metabolism, bradycardia, lethargy.
Hyperthyroidism: Increased metabolism, tachycardia, anxiety.

Drugs for Hypothyroidism

Levothyroxine (T4) and Liothyronine (T3) are common treatments, with potential adverse effects like thyrotoxicosis and interactions with absorption-reducing drugs.

Description

This quiz covers the basics of anti-histamines and their sedative effects, along with treatments for asthma. It highlights specific examples of pharyngeal demulcents and their soothing properties. Test your knowledge on these essential pharmacological agents and their applications in respiratory conditions.

Asthma and Anti-histamines Overview

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Questions and Answers

What is the primary mechanism of action for salbutamol in treating asthma?

Which class of drugs includes short and long-acting agents for asthma treatment?

What should a patient do if more than 3 inhalations of salbutamol are needed within 24 hours?

Which of the following is NOT a type of bronchodilator used for asthma treatment?

What important safety advice should patients follow when using inhaled bronchodilators?

What is a potential contributing factor to hypertension related to vascular condition?

Which diastolic blood pressure range indicates severe hypertension?

Which of the following is NOT a non-pharmacological therapy for hypertension?

What is the primary mechanism by which diuretics lower blood pressure?

Which class of antihypertensive drugs includes medications like hydrochlorothiazide and furosemide?