Newsletter – January 2015 Chronic Cough in Adults Written by: Brent Springer – ISU Pharm D Candidate 2016
Idaho Drug Information Center Idaho State University 921 S. 8th Ave, Stop 8092 Pocatello, ID 83209-8092 208-282-4689 [email protected]
Rebecca Hoover, PharmD, MBA, Director, [email protected]
Ryan Jensen, PharmD Candidate 2016, Founding Editor
Coughing is an important defense mechanism to remove harmful or unwanted material from the upper respiratory tract. A normal, relatively healthy, cough should resolve in a few weeks, but when it doesn’t coughing can cause a number of harmful complications. Chronic cough is defined as a cough lasting continuously for eight weeks or more. 1,2,3 Identifying the cause of a chronic cough can be more difficult than acute coughs which are often associated with the common cold or seasonal allergies. Since pharmacists are one of the most readily accessible professionals within the health care system, understanding the various causes of chronic cough, both drug-‐ related and otherwise can help us to assist patients and other health-‐care professionals to provide evidence-‐based therapies for this condition. A significant number of chronic coughs are attributed to multiple causes and a careful workup is required. Be aware that a small percentage of chronic coughs are idiopathic. 3 One of the most commonly reported drug-‐related origins of chronic cough is ACE inhibitors such as lisinopril, although overall, cause of a mere 1-‐3% of chronic cough cases. 4 ACE Inhibitors are thought to sensitize cough receptors through a buildup of prostaglandins and bradykinin. Oxymetazoline (Afrin) has also been associated with chronic cough but is not mentioned extensively in the available literature. The following paragraphs describe several of the more common non-‐drug causes of chronic cough:
Newsletter – January 2015 Gastroesophageal Reflux (GERD): A segment of the patients who experience chronic cough are diagnosed with GERD and often empirically treated with proton-‐pump inhibitors (PPIs). These patients often do not exhibit any other symptoms of GERD. Physicians may order a 24-‐hour pH Study and/or endoscopy procedures to verify this diagnosis.1,2,5 Upper Airway Cough Syndrome (Post-‐Nasal Drip): Often associated with frequent clearing of the throat due to rhinitis, with or without sinusitis. Allergic rhinitis is commonly treated with newer generation antihistamines, although treatment may include therapy with mast cell stabilizers and nasal corticosteroids. Non-‐allergic rhinitis, due to the common cold and other causes, is often treated with diphenhydramine/decongestant combinations. 2 A number of over-‐the-‐counter (OTC) therapies are available. Pharmacists may recommend an initial trial of OTC medications followed by a provider referral if the symptoms persist. Asthma: Chronic cough is a common symptom of asthma and with cough-‐variant asthma, is the only symptom. Elderly patients with asthma may only present with a chronic cough. 5 If asthma is suspected, an immediate referral to a provider is warranted. Once asthma has been diagnosed, pharmacists should be able to provide patients with accurate information regarding drug therapy for this disease. All patients with asthma should have a short-‐acting beta agonist (SABA) inhaler and should understand its proper use. Other common therapies include long-‐acting beta agonists, inhaled corticosteroids, leukotriene receptor antagonists, and mast cell stabilizers. Smoking: Users of tobacco are three times more likely to experience chronic cough compared to non-‐users. 5 Tobacco smoke can reduce or even paralyze the action of the mucociliary escalator – the ciliated epithelium of the respiratory tract. Pharmacists should take every opportunity to encourage smoking cessation and recommend evidence-‐based therapies to assist patients with a desire to quit. Smoking is a major cause of COPD. Chronic Bronchitis/COPD: Persistent exposure to tobacco smoke and/or other environmental irritants contribute heavily to this condition. 5,6 Chronic cough may be an early indicator of COPD. Many of the same drugs used in asthma are also used to help manage COPD and Chronic Bronchitis. If COPD is suspected, provider referral is necessary. A 1998 study found that asthma, upper-‐airway cough syndrome, and GERD accounted for the majority of chronic cough diagnoses. 1 By thorough clinical assessment, the underlying cause of chronic cough can be determined and appropriate therapy initiated. Antitussive therapy, both prescription and OTC, may be warranted in some cases.6,7 Pharmacists should be able to provide patients with accurate information to help manage the various drug therapies available for this distressing condition. See appendix 1 (page 5) for recommendations in treating chronic cough.
Newsletter – January 2015 Question of the Month: Do Fentanyl transdermal patches contain metal and can they safely be used during a MRI? Written By: Brigham Wilcox – ISU Pharm D Candidate 2015
Some Fentanyl transdermal patches may contain a metal backing usually used to separate the active ingredient from other portions of the patch, such as adhesive. The metal contained in transdermal patches is usually aluminum but could also be titanium dioxide or other metals. Due to their ability to conduct electricity, the metal in the patch can become very hot causing severe burns if worn during an MRI. Keep in mind not all metal backing are visible on the patches. The chart below summarizes the results of our research on this topic. Encourage patients and providers to disclose all transdermal patch use to the imaging lab.
* -‐ Have not studied the fentanyl transdermal patch in MRI ѱ-‐ Printed ink contains minimal amounts of titanium dioxide, remainder of patch is metal free † -‐ Safe for use in MRI ‡ -‐ May contain trace heavy metals that are within USP limits, but safe in MRI
Newsletter – January 2015
OTC Sodium Phosphate Warning Written by: Alicia Romero – Pharm D
On January 8, 2014 the FDA issued a safety warning regarding OTC sodium phosphate and sodium biphosphate products used for the treatment of constipation (ie. Fleet® and corresponding generics). This warning was for both oral products and enemas. When these products were taken in larger doses than recommended or more frequent than one dose per day, serious electrolyte disturbances have occurred. Electrolyte imbalances can lead to severe dehydration, acute renal injury, other organ damage including the heart, and even death. Of the 54 reports submitted to the FDA regarding electrolyte imbalance, 13 resulted in death showing that although rare, these electrolyte imbalances should not be taken lightly. This serious adverse event occurs, on average, 1-‐2 days after incorrect product usage. If patients purchase or seek counseling on this product, be sure to identify any risk factors that may exclude them from safely using OTC sodium phosphate products. These risk factors include dehydration, heart or kidney problems, bowel inflammation or obstruction, and current medications that may influence electrolyte balance such as ACE inhibitors, ARB’s, diuretics or NSAIDS. It is typically a safe practice to avoid recommending these products for children. Proper usage instructions need to be a priority due to these serious adverse events in the FDA warning.
Newsletter – January 2015 Appendix 1: Recommendations for the Treatment of Chronic Cough General Recommendations for the Treatment of Chronic Cough Implement non-‐pharmacological treatment plus acid Gastroesophageal Reflux (GERD) 6,8 suppression therapy. Non-‐pharmacological treatments include: diet restrictions, raising head while sleeping, and weight reduction. Acid suppression is usually a PPI. Some PPI options include omeprazole 20-‐40mg, lansoprozole 30mg, and pantoprazole 40mg usually taken once daily before a meal. If cough is resistant, more studies may be performed and in certain situations patients may benefit from the addition of a prokinetic drug (ie. Metoclopramide 10mg up to four times daily before meals and bedtime) Treatment of what was formerly known as post-‐nasal drip 6,8 Upper Airway Cough Syndrome should initially be a first generation antihistamine and/or a (Post-‐Nasal Drip) decongestant. Diphenhydramine 25-‐50 mg before bedtime would be a great first choice. Decongestants pose some risks if used long term. Nasal decongestants, such as Afrin®, should only be used for a few days, while oral pseudoephedrine should be used with caution in patients with cardiovascular risks. Chronic cough as a result of asthma is best treated in the Asthma 6,8 same way as asthma without a cough. Patients should ideally be prescribed a rescue bronchodilator such as Albuterol and should also have an inhaled corticosteroid for maintenance (ie. Low dose fluticasone inhaled twice daily) The best recommendation is smoking cessation. Avoiding 6,8 Smoking other irritants may help, but around 90% of those who quit smoking experience relieve of chronic cough. If the determined cause of chronic cough is linked to Rhinitis 6,8 rhinitis, topical corticosteroids (ie. fluticasone nasal spray) are first line therapy. Other options include topical ipratropium (40 mcg BID) or a 1st generation antihistamine. Wait and observe. Post-‐infection 6 Antitussive agents have not been proven to be highly ANTITUSSIVE/PROTUSSIVE effective in chronic cough. In some select cases they may be 8 THERAPY chosen. Some options include codeine, dextromethorphan, and diphenhydramine. Estimated minimal effective doses are as follows: codeine 20 mg, dextromethorphan 20 mg, and 25 mg diphenhydramine. Codeine, although considered more effective by some, has high patient variability and has a high incidence of nausea. Protussive therapy for chronic cough has not shown any merit and lacks evidence of efficacy. (ie. Guaifenesin)
Newsletter – January 2015 References
Chronic Cough in Adults 1. From a Prospective Study of Chronic Cough, Nicholas A. Smyrnios, Richard S. Irwin, Frederick J. Curley, Cynthia L. French. Archives of Internal Medicine, 1998 June 8; 158: 1222-‐1228 2. How should one investigate a chronic cough?, Ryu P.H. Tofts, Gustave Ferrer, Eduardo Olivera. Cleveland Clinic One Minute Consult, 2011 February; 78(2): 84-‐89, www.clevelandclinicmeded.com/medicalpubs/ccjm/investigating-‐chronic-‐cough-‐2-‐2011, Accessed August 26, 2014 3. Cough: an unmet clinical need, Peter V. Dicpinigaitis, British Journal of Pharmacology, 2011; 163: 116-‐ 124, www.brjpharmacol.org, Accessed August 28, 2014 4. Irwin RS, Boulet LP, Cloutier MM, et al. Managing cough asa defense mechanism and as a symptom. A consensus panel report of the American College of Chest Physicians. Chest. 1998 Aug;114(2 Suppl Managing):133S-‐181S. 5. Chronic Cough 1: Prevalence, pathogenesis, and causes of chronic cough, Kian Fan Chung, Ian D. Pavord, Lancet, 2008 April 19; 371: 1364-‐74 6. Chronic Cough 2: Management of chronic cough, Kian Fan Chung, Ian D. Pavord, Lancet, 2008 April 19; 371: 1375-‐84 7. Cough management: a practical approach, De Blasio et al. Cough, 2011; 7(7), www.coughjournal.com/content/7/1/7, Accessed August 27, 2014 8. Irwin RS, Baumann MH, Bolser DC, et al. American College of Chest Physicians (ACCP). Diagnosis and management of cough executive summary: ACCP evidence-‐based clinical practice guidelines. Chest. 2006 Jan;129(1 Suppl):1S-‐23S. 9. Image (page 1: left-‐hand side) courtesy of iStockphoto/drbimages Question of the Month: Do Fentanyl transdermal patches contain metal and can they safely be used during a MRI? 1. U.S. Food and Drug Administration. 2011. Risk of burns during MRI scans from transdermal drug patches with metallic backings. Retrieved from http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders 2. Alhammad A, Durand C, Willett KC. Practical considerations for optimal transdermal drug delivery. American Journal of Health-‐System pharmacy. 2012;69(2):116-‐124. 3. Wilcox, B. Personal interview/correspondence. Drug information Specialists of JANSSEN, MYLAN, SANDOZ, ACTAVIS, APOTEX, MALLINKRODT, PAR, AND UPSHER-‐SMITH. 2014
OTC Sodium Phosphate Warning 1. U.S. Food and Drug Administration. 2014. Sodium Phosphate Over-‐the-‐Counter Products: Drug Safety Communication -‐ Possible Harm From Exceeding Recommended Dose. Retrieved from http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders 2. Image (page 4: left-‐hand side) courtesy of drugs.com