Cough 2019 PDF

Community pharmacy Cough Ola Ali Nassr lecturer Al-Mustansiriyah University [email protected]  Coughing is: body’s defence mechanism to clear the airways of foreign bodies and particulate matter. This is supplemented by cilia in the bronchi that m...

Community pharmacy Cough Ola Ali Nassr lecturer Al-Mustansiriyah University [email protected]  Coughing is: body’s defence mechanism to clear the airways of foreign bodies and particulate matter. This is supplemented by cilia in the bronchi that move mucus and entrapped foreign bodies to be expectorated or swallowed. Cough can be very debilitating to the patient’s well-being and can also be disruptive to family, friends and work colleagues The British Thoracic Society Guidelines (2019) state that cough is usually self-limiting and will resolve in 3 or 4 weeks without the need for antibiotics.  Coughs can be described as: – productive (chesty) or – nonproductive(dry, tight, tickly). – However, many patients will say that they are not producing sputum, although they may go on to say that they ‘can feel it on their chest’. In these cases, the cough is probably productive in nature and should be treated as such. Coughs are classified as follows: Acute when present for less than 3 weeks Subacute when present for 3 to 8 weeks Chronic when present for more than 8 weeks Epidemiology In community pharmacy, the figures are high, with at least 24 million visits per year. Schoolchildren experience the greatest number of coughs, with an estimated 7 to 10 episodes per year (compared with adults, with two to five episodes per year). Acute viral URTIs exhibit seasonality, with a higher incidence seen in the winter months  Aetiology The vast majority (90%) of URTIs are caused by viruses. These include respiratory syncytial virus, rhinovirus and viral influenza. The remaining 10% of infections involve bacteria and include Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus and Klebsiella pneumonia cough reflex is responsible for cough production. Receptors located mainly in the pharynx, larynx, trachea and bronchi are stimulated via mechanical, irritant or thermal mechanisms. Neural impulses are then carried along afferent pathways of the vagal and superior laryngeal nerves, which terminate at the cough centre in the medulla. Efferent fibres of the vagus and spinal nerves carry neural activity to the muscles of the diaphragm, chest wall and abdomen. These muscles contract and are followed by the sudden opening of the glottis, which creates the cough.  Clinical features of acute viral cough Viral coughs typically present with sudden onset and associated fever. Sputum production is minimal, and symptoms are often worse in the evening. Associated cold symptoms are also often present; these usually last between 7 and 10 days. A duration of longer than 14 days might suggest postviral cough or possibly indicate a bacterial secondary infection A common misconception is that cough with mucopurulent sputum is bacterial in cause and requires referral.  Conditions to eliminate Likely causes 1. Upper airways cough syndrome (UACS) This was previously referred to as postnasal drip UACS is characterized by a sinus or nasal discharge that flows behind the nose and into the throat, (i.e., patients describe something stuck in the throat). Patients should always be asked whether they are swallowing mucus or notice that they are clearing their throat more than usual. Chronic cough is also associated with UACS.  Allergies are one cause of UACS. Coughs caused by allergies are often nonproductive and worse at night. However, there are usually other associated symptoms, such as sneezing, nasal discharge or blockage, conjunctivitis and an itchy oral cavity. Cough of an allergic origin might show seasonal variation; for example, hay fever. Other causes include vasomotor rhinitis (caused by odours and changes in temperature/humidity) and postinfectious UACS after a URTI. If UACS is present, it is better to direct treatment at cause of the UACS (e.g., antihistamines or decongestants) rather than just treat the cough. E.g Actified  2. Acute bronchitis Most cases are seen in autumn or winter, and symptoms are similar to those of viral URTI, but patients also tend to exhibit dyspnoea and wheeze. The cough usually lasts for 7 to 10 days but can persist for 3 weeks. The cause is normally viral, but is sometimes bacterial. Symptoms will resolve without antibiotic treatment, regardless of the cause. If the person is systemically unwell, referral is appropriate.  Unlikely causes 1.Laryngotracheobronchitis (croup) Symptoms are triggered by infection with parainfluenza virus affects infants aged between 3 months and 6 years and affects 2% to 6% of children. it is more common in the autumn and winter months. Symptoms occur in the late evening and night. The cough can be severe and violent and is described as having a barking (seal-like) quality. In between coughing episodes, child may be breathless and struggle to breathe properly. Typically, symptoms improve during the day and often recur again the following night, with most children seeing symptoms resolve in 48 hours. Standard treatment for children would be oral or intramuscular dexamethasone 2. Chronic obstructive pulmonary disease ( COPD) characterized by destruction of lung tissue and is preferred term for chronic bronchitis (CB), emphysema and chronic obstructive airways disease. It is characterized by cough, sputum production and increasing breathlessness; it is treatable although not curable. Typical symptoms include chronic cough, breathlessness on exertion, wheezing and recurrent chest infections. Confirmation of the diagnosis is by spirometry testing. Patients with established COPD often experience acute exacerbations marked by a reduction in activities and more pronounced breathlessness. In such cases, the patient requires referral to the GP for potential antibiotics and steroid therapy. A history of smoking is the single most important factor in the cause of CB  3. Asthma Asthma is a chronic inflammatory condition of the airways characterized by coughing, wheezing, chest tightness, and shortness of breath. Typically, these symptoms tend to be variable, intermittent, worse at night, and provoked by triggers (e.g., allergens, infections, irritant exposure). asthma can also present as a nonproductive cough (or minimally productive) especially in young children, in whom the cough is often worst at night and recurrent 4. Pneumonia (community-acquired) Bacterial infection is usually responsible for pneumonia and is most commonly caused by S. pneumoniae (80% of cases) Initially, the cough is nonproductive and painful (first 24–48 hours), but it rapidly becomes productive, with sputum being stained red. The cough tends to be worst at night. The patient will be unwell, with a high fever (>38o C), malaise, headache, and breathlessness and experience pleuritic pain (inflammation of pleural membranes, manifested as pain to the sides) that worsens on inspiration. Older patients are often afebrile and may present with confusion  5. Medicine-induced cough or wheeze A number of medicines may cause bronchoconstriction, which presents as coughing or wheezing. Angiotensinconverting enzyme (ACE) inhibitors are most commonly associated with cough. The incidence might be as high as 16% and time to onset is variable, ranging from a few hours to more than 1 year after the start of treatment. Cough invariably ceases after withdrawal of the ACE inhibitor but takes 3 to 4 weeks to resolve. Other medications associated with cough or wheeze are nonsteroidal antiinflammatory drugs (NSAIDs) and beta blockers.  Very unlikely causes Heart failure Bronchiectasis Tuberculosis Carcinoma of the lung Lung abscess Spontaneous pneumothorax Gastro-oesophageal reflux disease Nocardiosis and psychogenic cough  Patients should not be routinely prescribed antitussives but instead encouraged to drink more fluids and told that their symptoms will resolve in time on their own. If recommended, dextromethorphan is the only agent with any evidence of effectiveness; its side effect profile and abuse tendency rather than clinical efficacy may drive this choice. On this basis, dextromethorphan would be first-line therapy and pholcodine second-line treatment.  Evidence base for over-the-counter medication 1. Expectorants for wet cough Based on studies, guaifenesin is the only expectorant with any evidence of effectiveness. Given its proven safety record, absence of drug interactions, and the public’s desire to treat productive coughs with a home remedy, it would seem reasonable to supply OTC cough medicines containing guaifenesin.  2.Cough suppressants (antitussives) for dry cough Cough suppressants act directly on the cough centre to depress the cough reflex. – Codeine – Pholcodine – Dextromethorphan 3. Demulcents Demulcents, such as simple linctus and honey, are pharmacologically inert and are used on the theoretical basis that they reduce irritation by coating the pharynx and thus prevent coughing. However, there is no evidence for their efficacy  4. Antihistamines could reduce some of the symptoms of a cold: runny nose (rhinorrhoea) and sneezing. These effects are due to anticholinergic action of antihistamines. The older drugs (e.g. chlorphenamine (chlorpheniramine), promethazine) have more pronounced anticholinergic actions than the non-sedating antihistamines (e.g. loratadine, cetirizine, acrivastine). Therefore non-sedating antihistamines are less effective in reducing symptoms of a cold. Antihistamines are not so effective at reducing nasal congestion.  Some (e.g. diphenhydramine) may also be included in cold remedies for their supposed antitussive action or to help the patient to sleep. Evidence indicates that antihistamines alone are not of benefit in the common cold but that they may offer limited benefit for adults in combination with decongestants, analgesics and cough suppressants.  Interactions: The problem of using antihistamines, particularly the older types (e.g. chlorphenamine), is that they can cause drowsiness. Alcohol will increase this effect, as will drugs such as benzodiazepines or phenothiazines that have the ability to cause drowsiness or CNS depression. Antihistamines with known sedative effects should not be recommended for anyone who is driving, or in whom an impaired level of consciousness may be dangerous (e.g. operators of machinery at work). Because of their anticholinergic activity, the older antihistamines may produce the same adverse effects as anticholinergic drugs (i.e. dry mouth, blurred vision, constipation and urinary retention). These effects are more likely if antihistamines are given concurrently with anticholinergics such as hyoscine or with drugs that have anticholinergic actions such as tricyclic antidepressants or bladder antispasmodics (e.g. oxybutynin)  Interactions Alcohol Hypnotics Sedatives Betahistine Anticholinergics Side effects Drowsiness (driving, occupational hazard) Constipation Blurred vision Urinary symptoms Confusion Cautions Closed-angle glaucoma LUTS in men Epilepsy Liver disease Children under 6 years old In March 2009, an important statement was issued by the Medicines and Healthcare products Regulatory Agency (MHRA), which says: The new advice is that parents and carers should no longer use over-the-counter (OTC) cough and cold medicines in children under 6. – There is no evidence that they work and – they can cause side-effects, such as allergic reactions, effects on sleep or hallucinations. – The risks of side-effects are reduced in older children. This is because they weigh more, get fewer colds and can say if the medicine is doing any good.  Antitussives: Dextromethorphan and pholcodine Expectorants: Guaifenesin and ipecacuanha Nasal decongestants: Ephedrine, oxymetazoline, phenylephrine, pseudoephedrine and xylometazoline Antihistamines: Brompheniramine, chlorphenamine, diphenhydramine, doxylamine, promethazine and triprolidine Children aged between 6 and 12 years can still use these preparations, but with an advice to limit treatment to 5 days or less. The MHRA rationale was that for children aged over 6 years, the risk from these ingredients is reduced because: they suffer from cough and cold less frequently and consequently require medicines less often; with increased age and size, they tolerate the medicines better; and they can say if the medicine is working. Simple cough remedies (such as those containing glycerine, honey or lemon) are still licensed for use in children. Alternatively, for children over the age of 1 year, a warm drink of honey and lemon could be given. Remember that all aspirin-containing products are contraindicated in all children under the age of 16. This includes oral salicylate gels. WHY?  A NICE guideline says that antibacterials should be considered if: the person Is systemically very unwell Is at high risk of serious complications because of a pre-existing co-morbid condition such as heart, lung, kidney, liver or neuromuscular disease, or immunosuppression Is older than 65 years of age with two or more of the following, or older than 80 years with one or more of the following: – ◦ Hospital admission in the previous year – ◦ Type 1 or type 2 diabetes mellitus – ◦ Known congestive heart failure – ◦ Use of oral corticosteroids  Prevention of colds and flu Pharmacists should encourage those in at-risk groups to have an annual flu vaccination. In the United Kingdom, the health service now provides vaccinations to all patients over 65 years and those below that age who have chronic respiratory disease (including asthma), chronic heart disease, chronic renal failure, chronic neurological disease, and diabetes mellitus or immunosuppression due to disease or treatment. Pregnant women and people living in long-stay residential care are also advised to have immunization Increasing attention is being paid to ways of reducing transmission of flu, and this also applies to colds. Routine handwashing with soap and water for at least 20 seconds reduces the transmission of cold and flu viruses.