Cough and Cold Mechanisms

• Common ailments are frequently occurring, generally mild conditions that can cause discomfort or inconvenience.
• Understanding the management of common ailments is critical for pharmacists in providing effective patient counseling and therapeutic recommendations.
• Common ailments include the cold, headache, diarrhea, vomiting, anti-allergies, and drugs used in anaphylaxis.

Common Cold: Etiology and Pathophysiology

• The common cold is also referred to as rhinitis or upper respiratory tract infection (URI).
• A common cold is a self-limiting viral infection of the upper airways.
• Viruses that cause the common cold include rhinovirus, respiratory syncytial virus (RSV), and parainfluenza viruses (PIVs).
• Vasodilation and increased secretion of polymorphonuclear leukocytes and cytokines can be caused by viral infections.
• Nasal secretions are the usual mode of transmission, via hand contamination.

Common Cold: Signs and Symptoms

• The signs and symptoms from one virus to another have little to no variations.
• Common cold causes rhinorrhea (runny nose) and sneezing.
• Cold also causes a blocked nose
• Cold also causes a sore or itchy throat
• A mild fever may occur, but is rare for adults
• Patients may experience sleeplessness and discomfort
• Symptoms usually disappear in 5–7 days but persist in infants for 10-14 days.

Cough

• Cough is a powerful physiological reflex that clears the ventral airways of irritants and excess secretions.

Cough Types Based on Phlegm Production

• A productive cough, known as a wet cough, brings up mucus or phlegm.
• A non-productive cough, known as a dry cough, is where no mucus or phlegm is brought up.

Cough Types Based on Duration

• Acute cough lasts for less than three weeks.
• Subacute cough lasts three to eight weeks.
• Chronic cough persists over eight weeks.

Cough: Etiology

• Acute cough is caused by common cold, pneumonia, pulmonary embolism, and irritants.
• Subacute cough results from continued irritation of the cough receptors after an infection.
• Chronic cough may result from interstitial lung cancer, chronic bronchitis, GERD, asthma, and upper airway cough syndrome.

Cough: Pathophysiology

• Each cough occurs through the stimulation of a complex reflex arc.
• Coughing is initiated by irritation of cough receptors.
• Chemical receptors sensitive to acid, heat, and capsaicin-like compounds trigger the cough reflex via activation of the type 1 vanilloid (capsaicin) receptor.

Catarrh

• Catarrh involves a buildup of mucus in locations like the back of the nose, throat, or sinuses.
• Mucus is a slippery fluid substance produced by mucus glands in the nose and throat.
• Bodies make 1-2 quarts of mucus every day.
• Mucus drips down the back of the nose and into the throat, then descends into the stomach and digests.
• Mucus is produced to act as a form of lubricant in the lungs and airways and acts as a protective barrier against pathogens.
• Catarrh is an overflow of the watery and other constituents of blood, into the mucus and submucus connective tissue.

Catarrh: Etiology and Pathophysiology

• Catarrh etiology includes infections, nasal polyps, allergies, hormonal changes, and GERD.

Catarrh: Signs and Symptoms

• Catarrh signs and symptoms include difficulty swallowing, sore throat, and heat or pain in the face and nose.

Therapeutic Management of Cold, Cough and Catarrh

• There is no medicine available to cure common cold.
• Non-pharmacological and pharmacological therapy aims at relieving common cold symptoms while the body heals from the viral infection.
• Antibiotics should be avoided because the common cold is a viral infection.
• Treatment with antibiotics may be required if a common cold leads to secondary infections.

Non-pharmacological Therapeutic Management of Cold, Cough and Catarrh

• Managing cold, cough, and catarrh involves hydration, use of mentholated chest rub, nasal rinses, and chicken soup.
• Inhaling steam from herbal preparations of citrus plants boiled in hot water can help.
• Use of supplements like Vitamin C, zinc, and folic acid speeds up recovery rate and shortens clinical manifestation.
• Garlic may help stimulate the immune system.
• Honey, Ginger Tea, and Turmeric Tea relieve cough symptoms.
• Eucalyptus oil loosens phlegm.
• Patient Education, cough suppression techniques, breathing exercises, and sleeping on propped-up pillows can assist patients.
• Saline nasal drops or sprays may also provide relief.

Pharmacological Treatment of Cold and Catarrh

• Treatment includes antihistamines
• Antihistamines act by blocking histamine at H1 receptors.

Classes of Antihistamines

• First-generation Antihistamines
• Second-generation Antihistamines
• Third-generation Antihistamines

First-generation antihistamines

• Chlorpheniramine, 4 mg tablet every 4 hours, not to exceed 6 tablets/24 hours
• Chlorpheniramine, 1mg every 12 hours; for 2-5 year olds, and 6-12 year olds, 2mg every 4-6 hours
• Diphenhydramine, Adult dose, 25mg every 4 hours
• Diphenhydramine, Child dose (6-12 years old): 12.5 mg every 4 hours, for 2-6 year olds: 6.25 mg every 4 hours
• Contraindications: Hypersensitivity to antihistamines or any of the excipients, concurrent use with monoamine oxidase inhibitors.

Second Generation Antihistamines

• 10 mg of Loratadine, taken orally, once a day
• Children dose (2-12 years old, with body weight <30 kg): 5 mg taken once daily
• Body weight >30 kg; 10 mg taken once daily.
• Contraindications: hypersensitivity to loratadine or any component of the preparation.
• Drug interactions: Alcohol, erythromycin, cimetidine, ketoconazole, procarbazine and other antihistamines.

Decongestants

• Decongestants work by activating alpha-adrenergic receptors either by binding to them or stimulating the release of norepinephrine
• Oxymetazoline: 2 or 3 sprays in each nostril not more often than 10 to 12 hours.
• Oxymetazoline is not recommended to be used with children under 6 years old
• Adult Pseudoephedrine Dose: 60 mg every four to six hours.
• Children Pseudoephedrine Dose: 6 to 12yrs: 30 mg every 4 to 6 hrs, 4 to 6yrs: 15 mg every 4 to 6 hrs.
• Pregnancy and lactation: Pseudoephedrine should be avoided during the first trimester and lactation, suppresses milk production.

Pharmacological Treatment of Cough

• Cough remedies are categorized as antitussives and expectorants.
• Antitussives include: Codeine, Dextromethorphan and Noscapine

Codeine

• Codeine is a semisynthetic opioid analgesic and occurs in liquid dosage forms.
• Side effects include constipation, sedation, risk of addiction

Side effects of Guaifenesin

• Nausea and vomiting; rarely, hypersensitivity reactions.
• Contraindications: hypersensitivity to guaifenesin, bisulphates or to any of the excipients

Analgesics/Antipyretics

• Analgesic drugs, such as paracetamol, may be used in combination with some of the classes of drugs to aid relief of headache and other pain-related symptoms.
• Examples are paracetamol, ibuprofen, etc.
• Caution: Avoid decongestants in patients with hypertension or cardiovascular disease.

Headaches: Types and Symptoms

• Tension Headache: Dull, aching pain, often bilateral.
• Migraine: Unilateral throbbing pain, associated with nausea, photophobia, and aura.
• Cluster Headache: Severe, unilateral pain, often around the eye.

Management of Headaches

• Tension Headache Non-Pharmacological management includes relaxation techniques and stress management.
• Pharmacological management includes paracetamol, ibuprofen, and aspirin.
• Acute relief for Migraines include Sumatriptan, ergotamine, and NSAIDs.
• Migraine Prophylaxis: Beta-blockers (e.g., propranolol), antiepileptics (e.g., topiramate), and tricyclic antidepressants (e.g., amitriptyline).
• Acute relief for Cluster Headaches involve high-flow oxygen therapy and sumatriptan.
• Cluster Headaches can be prevented usingVeraramil and corticosteroids
• Avoid aspirin in children due to the risk of Reye's syndrome.

Diarrhoea and Vomiting

• Diarrhea involves increased stool frequency or liquidity caused by infections, food intolerance, or medication side effects.
• Vomiting may be caused by infections, motion sickness, pregnancy, or gastroesophageal reflux.

Management of Diarrhoea and Vomiting

• The Non-Pharmacological Management includes Oral rehydration therapy (ORT) to prevent dehydration and avoiding spicy or fatty foods.

Pharmacological Management For Diarrhea

• Loperamide (for non-infectious diarrhea).
• Zinc supplementation (in pediatric cases).
• Antibiotics (e.g., ciprofloxacin, metronidazole) for bacterial infections if indicated.

Pharmacological Management For Vomiting

• Antiemetics (e.g., metoclopramide, ondansetron).
• Antihistamines (e.g., promethazine) for motion sickness.
• Loperamide should be avoided in infectious diarrhoea with fever or bloody stools.

Anti-Allergies – Types of Allergies

• Allergic rhinitis (hay fever): An allergic reaction to airborne allergens like pollen, dust, or mould, causing symptoms such as sneezing, runny nose, itchy eyes, and nasal congestion.
• Urticaria (hives): A skin reaction characterized by red, itchy, and raised welts or patches that may appear and disappear, often triggered by allergens, stress, or irritants.
• Food or drug allergies: An immune response to specific foods or medications, leading to varying symptoms from mild (itching, swelling) to severe (anaphylaxis).

Management of Allergies

Non-Pharmacological Management

• Identify and avoid your known triggers, such as pollen, dust mites, and specific foods.
• Air purifiers or allergen-proof covers for mattresses or pillows are examples of items to eliminate allergens from your immediate environment.

Pharmacological Management

• Treatments commonly include Antihistamines, such as First-generation (e.g., chlorpheniramine, diphenhydramine) to cause sedation and Second-generation (e.g., loratadine, cetirizine) to act non-sedating.
• Allergic rhinitis can also be treated with Intranasal Corticosteroids like Examples include fluticasone and mometasone.
• Leukotriene Receptor Antagonists can be used with Examples including montelukast, used as adjunct therapy.

Anaphylaxis

• Anaphylaxis is a severe, life-threatening allergic reaction
• Symptoms include difficulty breathing, hypotension, swelling, and urticaria

Anaphylaxis Management

• Call for emergency help right away
• Place the patient in a supine position with legs elevated
• Administer Epinephrine (Adrenaline) as a first-line treatment with a dose of 0.3-0.5 mg, intramuscularly, every 5–15 minutes as needed.
• Administer antihistamines such as e.g., diphenhydramine or chlorpheniramine for urticaria and itching.
• Give Corticosteroids such as hydrocortisone and methylprednisolone to prevent late-phase reactions.
• Bronchodilators such as salbutamol, e.g., salbutamol (for bronchospasm).
• Caution: Monitor for rebound anaphylaxis within 24–48 hours.

Questions about the mechanisms, classification, and pathophysiology of coughs and the common cold. Includes causative agents and physiological processes. Addresses productive and non-productive coughs.