Colds PDF - Fall 2022

# Colds Prepared by Sara T. Taeb MSc. P522PT, Fall 2022 ## Definition A cold, also known as the common cold, is a viral infection of the upper respiratory tract. ## Pathophysiology of Colds - Colds are limited to the upper respiratory tract and primarily affect the following respiratory structu...

# Colds Prepared by Sara T. Taeb MSc. P522PT, Fall 2022 ## Definition A cold, also known as the common cold, is a viral infection of the upper respiratory tract. ## Pathophysiology of Colds - Colds are limited to the upper respiratory tract and primarily affect the following respiratory structures: pharynx, nasopharynx, nose, and paranasal sinuses. - More than 200 viruses cause colds, the majority of colds in children and adults are caused by rhinoviruses. - Viral and bacterial co-infection occurs but is rare. ## Clinical Presentation of Colds - A predictable sequence of symptoms appears 1 to 3 days after infection. - Sore throat is the first symptom to appear, followed by nasal symptoms (sneezing followed by profuse nasal discharge and congestion) which dominate by day 2 or 3. - Cough, although an infrequent symptom (<20%), appears by day 4 or 5. - Physical assessment of a patient with a cold may yield the following findings: - Slightly red pharynx with evidence of postnasal drainage, nasal obstruction, and mildly to moderately tender sinuses on palpation. - In addition, patients may have headache, low-grade fever, but colds are rarely associated with a fever above (37.8°C), and general malaise may be present. Most colds resolve in 1 week. ## Flu - Influenza is caused by RNA viruses, for which there are three types: A, B, and C. - Types A and B are most virulent, giving rise to flu symptoms, whereas type C produces mild cold like symptoms. - Patients often use the word flu when describing a common cold. However, subtle differences in symptoms between the two conditions should allow for differentiation. - It is helpful to remember that the flu season tends to occur between December and March, whereas the common cold, although more common in the winter months, can occur at any time. - The onset of influenza is sudden; the typical symptoms are shivering, chills, malaise, marked aching of limbs, insomnia, fatigue, a non-productive cough (cough in the common cold is usually productive) and loss of appetite. - Influenza is therefore normally debilitating, and a person with flu is much more likely to send a third party into a pharmacy for medication than present in person. Symptoms improve after approximately 5 days, with resolution after 1 week or more. ## Differentiation of Colds and Other Respiratory Disorders | Illness | Signs and Symptoms | |---|---| | Bacterial | Sore throat (moderate-severe pain), fever, exudate, tender anterior cervical adenopathy | | Colds | Sore throat (mild-moderate pain), nasal congestion, rhinorrhea, sneezing common; low-grade fever, chills, headache, malaise, myalgia, and cough possible (productive) | | Flu | Myalgia, chills, malaise, arthralgia, fever (37.8°C-38.9°C), sore throat, nonproductive cough, moderate-severe fatigue, loss of appetite. | ## Myths and Truths about Common Cold - **Myth #1:** You can catch a cold by not wearing a jacket in chilly weather. - **Myth #2:** If your symptoms last longer than a week, it's not a cold. - **Myth #3:** Nonprescription cold medicines can help you recover faster. - **Myth #4:** Vitamin C, Echinacea, and zinc will make you better faster. - **Myth #5:** If you have a cold, taking an antibiotic can't hurt and might even help. - **Myth #6:** It's hopeless! There's nothing you can do to ward off colds. ## Treatment of Colds ### Treatment Goals Because there is no known cure for colds, the goal of therapy is to: 1. Prevent transmission of cold viruses. 2. Reduce bothersome symptoms. ### General treatment approach - Antibiotics are ineffective against viral infections. ### Non pharmacologic Therapy - Nondrug therapy includes: - Increased fluid intake. - Adequate rest. - A nutritious diet as tolerated. - Increased humidification with: - Steamy showers. - Humidifiers (cool mist) or. - Vaporizers (hot water steam). - Saline nasal sprays or drops moisten irritated mucosal membranes and loosen encrusted mucus; salt gargles may ease sore throats. - Nondrug therapy for infants includes upright positioning to enhance nasal drainage. Also, because children typically cannot blow their own noses until about 4 years of age, carefully clearing the nasal passageways with a bulb syringe may be necessary if accumulation of mucus interferes with sleeping or eating. - Stuffy nose in babies: Saline nose drops can be used from birth to help with congestion. This would be a more suitable and safer alternative than a topical sympathomimetic. ### Pharmacologic Therapy - **Decongestants**: - Decongestants specifically treat sinus and nasal congestion. They are adrenergic agonists (sympathomimetic). Stimulation of alpha-adrenergic receptors constricts blood vessels, thereby decreasing sinusoid vessel engorgement and mucosal edema. - There are three types of decongestants: - **Direct-acting decongestants** (phenylephrine, oxymetazoline, and tetrahydrozoline) bind directly to adrenergic receptors. - **Indirect-acting decongestants** (ephedrine) displace norepinephrine from storage vesicles in prejunctional nerve terminals. - **Mixed decongestants** (pseudoephedrine) have both direct and indirect activity. - The systemic nonprescription decongestants include pseudoephedrine and phenylephrine. - Pseudoephedrine is well absorbed after oral administration; phenylephrine has a low oral bioavailability (approximately 38%). Both have short half-lives 6 hours and 2.5 hours respectively. Peak concentrations occur at 0.5-2 hours after oral administration. - **Intranasal nonprescription decongestants** include: - **The short-acting decongestants**: ephedrine, levmetamfetamine (L-desoxyephedrine), naphazoline, phenylephrine, propylhexedrine. - **Ephedrine**: Adults and children older than 12 years should put one or two drops into each nostril up to four times daily when required. - **The long-acting decongestants**: xylometazoline (8-10 hours) and oxymetazoline (12 hours). - These agents are longer acting than ephedrine and require less frequent dosing, typically two or three times a day. It is recommend to be used from 12 years upwards. - **Except Otrivine Child Nasal Drops**, which can be given to children over the age of 6 (one or two drops into each nostril once or twice daily). - Decongestants are indicated for temporary relief of nasal and eustachian tube congestion, and cough associated with postnasal drip. - Topical decongestants are convenient dosage forms and are effective in relieving nasal congestion; however, their use is limited to 3 to 5 days owing to concerns about RM (Rhinitis medicamentosa, i.e., rebound congestion). - When comparing the topical decongestants, the major differences are duration of action, dosage formulation (e.g., mist vs. spray vs. drops), moisture content and preservative content. - Nonprescription decongestants are not approved by FDA to self-treat nasal congestion associated with sinusitis. - The adverse effects are more common with systemic decongestants, because topical decongestants are minimally absorbed. - Decongestants are contraindicated in patients receiving concomitant MAO inhibitors. - Decongestants may exacerbate diseases sensitive to adrenergic stimulation, such as hypertension, hyperthyroidism, diabetes mellitus, coronary heart disease, ischemic heart disease, elevated intraocular pressure, and prostatic hypertrophy. - Patients with hypertension should use decongestants only with medical advice. - Clinicians should be aware of patients wishing to purchase large quantities of pseudoephedrine that may be used illegally to produce methamphetamine. - In 2005 classification of pseudoephedrine changed to “scheduled listed chemical products". - **Antihistamines:** - Reviews have shown that monotherapy with nonprescription antihistamines is not effective in reducing rhinorrhea and sneezing due to colds. - However, a combination of first-generation (sedating) antihistamines and decongestants showed benefit in adults. - Apart from questions of efficacy, an important issue is whether potential benefits of sedating antihistamines outweigh known risks associated with these drugs. ## Local Anesthetics - A variety of products containing local anesthetics is available for the temporary relief of sore throats. - Some products contain local antiseptics and/or menthol or camphor. Local antiseptics are not effective for viral infections. - **Vitamin C**: Only a small number of studies have demonstrated the ability of V. C (dose >1g/day) to reduce the frequency or severity of common cold. ## Systemic Analgesics - Systemic analgesics (e.g., aspirin, acetaminophen, ibuprofen, or naproxen) are effective for aches or fever sometimes associated with colds. - Aspirin-containing products should not be used in children with viral illnesses because of the risk of Reye's syndrome. ## Antitussives and Protussives (Expectorants) - When present, cough associated with colds is usually productive. - The use of antitussives (codeine or dextromethorphan) have questionable efficacy in colds and are not recommended. Guaifenesin, an expectorant, has not been proven effective in natural colds. ## Garlic - One trial suggests that garlic may prevent occurrences of the common cold, but more studies are needed to substantiate these findings. ## Zinc lozenges - Doses more than 75mg per day of acetate salty decrease duration of colds. ## Combination Products - Decongestants and antihistamines are marketed in many combinations, including decongestant/antihistamine combinations and various combinations with analgesics, expectorants, and antitussives. - Products are also marketed for daytime or night time use. - Products for nighttime use usually contain a sedating antihistamine, whereas daytime products do not. - Combination products are convenient, but the convenience must be weighed against the risks of taking unnecessary drugs. ## Product Selection Guidelines; Special Populations ### Pregnancy and breast feeding - Drug use during pregnancy and lactation is a balance between risk and benefit. - Because most colds are self-limiting, with bothersome rather than life-threatening symptoms, many clinicians recommend nondrug therapy. - Oxymetazoline is poorly absorbed after intranasal administration and is the preferred topical decongestant during pregnancy. ### Children - Currently, FDA does not recommend nonprescription cold medications for children younger than 2 years because of the lack of efficacy and risk of misuse or overuse leading to adverse events and death. - Manufacturers have voluntarily updated product labeling to include the statement; - "Do not use in children under four years of age" and added warnings to antihistamine-containing against their use for sedation purposes. - Health care providers should emphasize nondrug measures in children and, if pharmacotherapy is deemed necessary, parents should follow dosing instructions carefully and avoid combination products to avoid overdosage and this can be achieved by using dispensing devices (dropper, cup, syringe, or spoon). ## Patient Counseling for Colds - Nondrug measures may be effective in relieving the discomfort of cold symptoms. - The practitioner should explain the appropriate nondrug measures for the patient's particular symptoms. - For patients who prefer to sell nonprescription medications, the purpose of each medication should be described, and the patient should be counseled to use only medications that target their specific symptoms. - Patients need an explanation of possible side effects, drug interactions, and precautions or warnings. - Finally, the practitioner should explain the signs and symptoms that indicate the disorder is worsening and that medical care should he sought. ## Limiting viral spread 1. Use disposable tissues rather than handkerchiefs. 2. Wash hands frequently, especially after nose blowing. 3. Do not share hard towels. 4. Try to avoid touching your nose. 5. Avoid excessive doses of analgesia unknowingly. ## Administration of nasal drops The best way to administer nose drops is to have the head in the downward position facing the floor. Tilting the head backward and towards the ceiling is incorrect because this facilitates the swallowing of the drops. However, most patients will find the latter way of putting drops into the nose much easier than the former. ## Referral - Acute sinus fails to respond to OTC medications. - Middle ear pain fails to respond to OTC analgesics. - Patients with symptoms indicative of flu. ## Sore throat - Any part of the respiratory mucosa of the throat can exhibit symptom of pain this includes pharynx and tonsils. - Viral infection accounts for between 70% and 90% of all sore throat ceases. - Because most sore throats are viral in origin and self-limiting, medication aims to relieve symptoms and discomfort while the infection runs its course. - Lozenge and spray formulations incorporating antibacterial and anesthetics provide the mainstay of treatment. In addition, systemic analgesics and antipyretics will help reduce the pain and fever associated with sore throat. ## Antibacterial and antifungal agents - Antibacterial agents include chlorhexidine and benzalkonium chloride. - They have antibacterial activity and some inhibit Candida albicans growth. The use of antibacterial and antifungal agents should not be routinely recommended because the vast majority of sore throats are caused by viral infections against which they have no action. However, because adverse effects are rare, and stimulation of saliva from sucking the lozenge may confer symptomatic relief. ## Local anesthetics - Lidocaine spray is licensed for adults and children over the age of 12. - Benzocaine: Unlike lidocaine, benzocaine can be given to children in lozenge and spray formulations. Lozenges are available and can be given to children age 3 years and older. Additionally, children over the age of 6 can also use a spray formulation. - Both are safe for pregnant and breastfeeding women. ## Aspirin and saltwater gargle - Gargling with aspirin or saltwater is common remedy but without evidence of effectiveness. - Sucking a lozenge stimulate saliva production which in turn will lubricate the throat and thus exert a soothing action with a longer contact time. In contrast gargles have a short contact time with inflamed mucosa and therefore their effects will be short lived. ## Referral - Duration > 2 weeks. - Marked tonsillar exudate accompanied with high temperature and swallowing glands. - Dysphagia. - People who are taking medications that compromise immune system. ## Acute otitis media - Acute otitis media is commonly seen in children following a common cold and results from the virus spreading to the middle ear via the Eustachian tube, where an accumulation of pus in the middle ear or inflammation of the tympanic membrane (eardrum) results. - The overriding symptom is ear pain, but the child may rub or tug at the ear and become more irritable. - Referral to the GP would be appropriate for examination.