Untitled Quiz

Decongestants

• Indications for Use: Treat nasal congestion associated with the common cold, sinusitis, and allergies.
• Activity: Reduce nasal congestion by constricting blood vessels in the nasal passages. This decreases swelling and improves airflow.
• Pharmacological Mechanisms:
  • Alpha-adrenergic agonists: Stimulate alpha-adrenergic receptors in nasal blood vessels causing vasoconstriction.
  • Topical decongestants: Act directly on nasal mucosa.
  • Oral decongestants: Absorbed systemically, reaching nasal mucosa through the bloodstream.
• Advantages:
  • Rapid onset of action: Provide quick relief from congestion.
• Disadvantages:
  • Rebound congestion: Prolonged use can lead to worsening congestion.
  • Systemic side effects: May cause hypertension, insomnia, and nervousness when taken orally.

Antitussives

• Indications for Use: Reduce coughing associated with various conditions like the common cold, bronchitis, and pneumonia.
• Activity: Suppress the cough reflex by acting on the central nervous system or the peripheral nervous system.
• Pharmacological Mechanisms:
  • Centrally-acting antitussives: Suppress the cough center in the medulla oblongata of the brain.
  • Peripherally-acting antitussives: Reduce cough sensitivity in the airways.
• Advantages:
  • Effective in reducing cough frequency and severity: Can improve sleep and quality of life during episodes of excessive coughing.
• Disadvantages:
  • Sedation: Some antitussives can cause drowsiness.
  • Dependence: Long-term use can lead to dependence.

Expectorants

• Indications for Use: Loosen and thin mucus in the respiratory tract to facilitate its removal through coughing.
• Activity: Help clear the airways of excess mucus, typically in conditions like bronchitis and pneumonia.
• Pharmacological Mechanisms:
  • Stimulate mucus secretion: Increase the volume and fluidity of respiratory mucus, making it easier to cough up.
  • Reduce mucus viscosity: Thin the mucus, allowing it to flow more easily.
• Advantages:
  • Improve mucus clearance: Promote easier expectoration of phlegm or mucus.
• Disadvantages:
  • Gastrointestinal upset: Some expectorants can cause nausea and vomiting.

The Human Nasal Cycle

• Physiological Rhythm: The nasal passages alternate between congested and decongested states.
  • This cycle occurs every 4-8 hours naturally.
• Neural Control: The cycle is regulated by the sympathetic and parasympathetic nervous systems.
• Vascular Mechanisms: The cycle involves alternating vasoconstriction (narrowing) and vasodilation (widening) of blood vessels in the nasal passages.

Allergic Rhinitis

• Inflammatory Cascade:
  • IgE-mediated mast cell activation: This causes the release of inflammatory mediators.
  • Release of inflammatory mediators: These contribute to nasal congestion, sneezing, and itching.
• Cellular Response:
  • Eosinophil infiltration: Eosinophils contribute to the inflammatory response.
  • T-helper cell activation: These cells release cytokines and contribute to the inflammatory response.
  • Cytokine release patterns: These patterns influence the severity and duration of allergic rhinitis symptoms.
• Vascular Changes:
  • Increased capillary permeability: Leads to increased fluid leakage and nasal mucosal swelling.
• Neurogenic Response Amplification:
  • Sensory nerve stimulation: Increases sensitivity to nasal irritants.
  • Neuropeptide release: Further contributes to inflammation and symptom severity.