Respiratory: Common Cold

Common Cold

Self-Limiting Viral Infection of Upper Respiratory Tract

Typical Season: August to April

Pathophysiology

• Increased Susceptibility

  • Crowded classrooms/daycare, weakened immune system, smoking, allergies, chronic stress, sleep deprivation

• Viral Transmission

  • self-inoculation (hands) and/or inanimate objects (ex: door knobs)

• Mechanism of Infection

  • Peak ~2 to 4 days

• Present in Nasopharynx

  • ~16 to 18 days

Pathophysiology of Mechanism of Infection

• Virus binds to intercellular respiratory epithelium

• Replication

• Virus Spreads (peak ~2 to 4 days after inoculation)

Anti-Viral Treatment

none for common cold

Clinical Presentation

• Rhinoviruses (most common cause in adults and children)

  • Start 1-3 days after infection

• Symptoms

  • Nasal congestion, rhinorrhea, sneezing, low-grade fever, headaches, malaise

• Nasal Symptoms

  • 1. Clear, thin/watery secretions

  • 2. Thick, yellow/green secretion

  • 3. Clear, thin/watery secretions again

• Predictable Sequence

  • Sore Throat - Nasal Symptoms (Day 2-3) - Cough (Day 4-5)

Complications (Uncommon)

• Sinusitis

• Middle ear infection

• Bronchitis

• Pneumonia

• Asthma/COPD exacerbations

Treatment Goals

• Reduce symptoms

  • Rest and adequate fluid intake

• Prevent transmission

  • Stay home

  • Wash hands

Treatment Approach

• No cure

• No antibiotic use

  • Ineffective against viruses

• Non-pharmacologic

  • Mainstay

• Symptom specific treatment

  • Use of single ingredient products preferred

Exclusions for Self-Treatment

• Fever (Temperature >100.4)

• Chest Pain

• Shortness of Breath

• Worsening of Symptoms or Developmental of Additional Symptoms During Self-Treatment

• Concurrent Underlying Chronic Cardiopulmonary Disease

• AIDS or Chronic Immunosuppressant Therapy

• Frail Patients of Advanced Age

• Infants < 3 months old

• Hypersensitivity to Recommended OTC Medications

Always Recommend

Non-Drug Measures (such as adequate hydration and rest)

Table Path and Exclusions

Non-Pharmacologic Therapy (Mainstay of Treatment)

• Increased fluid intake

• Adequate rest

• Nutritious diet

  • Chicken soup

  • Lemon with honey

• Increased humidification or vaporization

• Proper hand hygiene

• Saline gargle

• Nasal irrigation

NETI Pot

• Helps w/ congestion

• Caution When Making

  • Use Boiled Water (get rid of brain-eating amoebas) and Allow to Cool

• Tonicity: Want Isotonic (0.9% Saline or NS)

Pharmacologic Therapy

• Decongestants (nasal/eustachian tube congestion)

• Antihistamines (rhinorrhea/sneezing, allergic rhinitis)

• Local anesthetics (pharyngitis)

• Systemic analgesics (fever, pain)

• Antitussives and protussives (cough)

• Combination products

Systemic Decongestants

Pseudoephedrine (best)

Phenylephrine

Pseudoephedrine

• Behind the counter, works much better than phenylephrine

  • Schedule C-V in some states (purchaser must show valid ID)

  • Limit 3.6 g per day and 9 g per month

• Largely being replaced by phenylephrine

• Main Ingredient of Methamphetamine (potential to make meth)

Phenylephrine

Does not work very well, may be removed from market (FDA in the process of proposing removal from the market due to studies showing ineffectiveness)

Direct Action

Phenylephrine, Oxymetazoline, and Tetrahyrdozoline

Indirect Action

Ephedrine

Mixed of Direct and Indirect Action

Pseudoephedrine

Decongestant Route of Administration

• Systemic

  • phenylephrine, pseudoephedrine

• Ophthalmic:

  • naphazoline, phenylephrine, oxymetazoline, and tetrahyrdozoline

• Intranasal:

  • Short-acting: ephedrine, epinephrine, naphazoline (Privine), phenylephrine (Vicks Sinex), and tetrahyrdozoline

  • Long-acting: oxymetazoline (Afrin)

Decongestant Information

• Indication: temporary relief of nasal and eustachian tube congestion

• MOA: adrenergic agonist

• Don’t use late at night (may keep up at night)

Decongestants: Adverse Reactions

• Cardiovascular stimulation

  • Increased blood pressure, tachycardia, palpitations, arrhythmias

• CNS stimulation

  • Restlessness, insomnia, anxiety, tremors, fear, hallucination

• Rebound congestion

  • Rhinitis medicamentosa: if use longer than 3-5 days, can make congestion worse once medication is withdrawn

  • Limit: 3-5 day supply of intranasal decongestant

Decongestants: Systemic Overdose

• Excess CNS stimulation

• Cardiovascular Collapse

• Shock

• Coma

Decongestants: Warnings

• May exacerbate disease sensitive to adrenergic stimulation (HTN, heart disease, diabetes, hyperthyroidism, etc.)

• Patients with HTN should use decongestants only with medical advice

Antihistamines First-Generation

• Are Sedating

• Not Effective Alone Against Common Cold

Antihistamines Second Generation

• Non-Sedating

  • Some find sedating

• Not Effective Against Common Col

Sedating Antihistamine + Decongestant

• Indicated for common cold

• May decrease rhinorrhea and sneezing due to cold

  • sneezing and cough, and anticholinergic effect (runny nose)

Topical Local Anesthetics

Benzocaine & Glycerin: Throat Spray

Phenol: Throat spray

Benzocaine: Lozenges

Topical Local Anesthetics Information

• Indication: temporary relief of sore throat

• Dosage forms available: lozenges, sprays, or mouthwashes

  • Step above lozenges, contain active ingredient (API is to help numb the throat)

Aspirin-Containing Products Warning

Should Not Be Used in Children with Viral Illness - Reye’s Syndrome

Rate Limiting/Max Doses: Acetaminophen

3,000 to 3,250 mg Daily

Rate Limiting/Max Doses: Ibuprofen

1,200 mg

Antitussives for Colds Associated w/ Non-Productive Cough

Codeine and Dextromethorphan = Not Recommended (Questionable Efficacy in Cold)

Protussive = Not Proven Efficacious in Colds

Complimentary Products

• Zinc

• Vitamin C (Ascorbc Acid)

• Oscillococcinum

Zinc

• Theoretical MOA: blocks adhesion of rhinovirus to nasal epithelium and inhibits viral replication

• Side effects: nausea, upset stomach, and bitter taste

Vitamin C (Ascorbc Acid)

• Reduces duration of cold by 8% in adults and 14% in children

• Ineffective for preventing colds in most people

• Airborne

Oscillococcinum

• Like treats like

Patient Encounter Questions

• Detailed description of symptoms

• Medical history and medication use

• Current or previous self-treatment

Patient Encounter Counseling

• Nondrug measures may be effective in relieving discomfort of cold symptoms

• Products should be selected based on specific symptom(s)

• Advise about proper use of medications

  • Duration of treatment

    • Adverse effects

  • Drug interactions

  • Cost

• Explain signs and symptoms requiring further evaluation by PCP