Proper Use of OTC Analgesics

Ms. Terrie is a clinical pharmacy writer based in Haymarket, Virginia.

A survey conducted by the National Council on Patient Education reports that an estimated 78% of individuals surveyed used OTC analgesics for the management of pain.1 Various OTC analgesics are frequently used for the treatment and management of headaches, fever, toothache, musculoskeletal injuries and disorders, as well as menstrual cramps. Statistics also report that an estimated 17% to 23% of the population use an OTC analgesic each week.² More than one third of OTC analgesic use is for the management and treatment of headaches.³ Almost 50% of patients who elect to use nonprescription analgesics do not read the labels of these products, however; more than 43% of those surveyed are not aware of the potential risks associated with taking these agents concurrently with certain prescription medications.³

According to results from a survey study conducted to ascertain basic knowledge about the use of OTC pain medications among patients seen in the emergency department, an increased potential exists for inappropriate use and adverse effects if patients are unaware of the risks.⁴ The study reported that significant gaps existed in patients’ knowledge about OTC pain medications. More than 40% of those surveyed did not know about potentially significant drug interactions or possible gastrointestinal (GI) side effects. More than 60% did not know about the relationship between the use of these agents and hepatic and renal disease, and more than 80% were unaware of the relationship between aspirin and adverse effects in asthmatics.⁴

Currently, oral OTC analgesics include acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs) (ibuprofen and naproxen), and salicylates (aspirin, magnesium salicylate, and sodium salicylate).³ Pharmacists should seize every possible opportunity to educate and assist patients in the proper selection and use of OTC analgesics. Selection of OTC analgesics should be based upon a careful assessment of a patient’s medical and medication profile, as well as allergy history. Prior to recommending any OTC analgesics, patients should always be screened for possible drug—drug interactions and contraindications.

On April 29, 2009, the FDA issued a final ruling that requires manufacturers of OTC analgesics and antipyretics to revise their labeling to include warnings about potential adverse effects (eg, internal bleeding, liver damage, concomitant warfarin therapy) associated with the use of these agents and to prominently display the active ingredients on the labels of both the packages and bottles. This labeling mandate is intended to assist patients in easily identifying the active ingredients and decrease the possibility of a patient inadvertently taking multiple products containing these analgesics concurrently. ⁵ Although these products are considered to be safe and effective when used appropriately, the FDA believes that patients need to be aware that these products have the potential to cause serious adverse effects, such as hepatoxicty and GI bleeding, when used improperly.⁵ This FDA action applies to all products that contain acetaminophen and NSAIDs. The revised labeling will also apply to those products that contain one of these ingredients in combination with other ingredients, such as in cough/cold and sinus medications. All OTC manufacturers of NSAID and acetaminophen products must comply with these labeling requirements by April 29, 2010. Specific labeling requirements for acetaminophen and NSAID products can be found at www.fda.gov/Drugs/NewsEvents/ucm144068.htm.

NSAIDs

Patients should be reminded to adhere to the recommended dosages and dosage intervals of NSAID products. The most common adverse effects associated with the use of NSAIDs include dyspepsia, nausea, heartburn, and epigastric pain. NSAIDs cause less GI upset and bleeding when compared with aspirin.³ Patients should be instructed to take NSAIDs with food, milk, or antacids if they experience GI upset. Patients with a history of impaired renal function, congestive heart failure, or medical conditions that compromise renal hemodynamics should not selfmedicate with NSAIDs.³ Patients with cardiovascular disease or those who are at high risk for cardiovascular disease or stroke should not use NSAIDs, unless under the supervision of a physician. ³ Some studies have reported that the use of NSAIDs is associated with an increased risk of myocardial infarction, heart failure, hypertension, and stroke.^3,6 The American Heart Association recommends that individuals with or at risk for hyperlipidemia, hypertension, or diabetes should avoid the use of NSAIDs.^3,6 They also recommend that patients use the lowest possible dose for the shortest duration.^3,6 The FDA recommends that patients use NSAIDs for no more than 10 days, unless otherwise directed by a physician.³ Examples of clinically significant drug interactions associated with the use of NSAIDs include bisphosphonates, beta-blockers, angiotensinconverting enzyme (ACE) inhibitors, digoxin, diuretics, anticoagulants, and methotrexate.³

Acetaminophen

Patients electing to use acetaminophen should be reminded that although acetaminophen is considered to be an effective analgesic and antipyretic, it does not have any anti-inflammatory activity. Patients should be reminded not to exceed the recommended daily dosages. Acetaminophen is potentially hepatoxic at doses greater than 4 g/day, especially with chronic use.³ Acetaminophen poisoning is considered to be one of the leading causes of acute hepatic failure in the United States and one of the primary reasons for communicating with poison control centers.³ Furthermore, more than 50% of acetaminophen-related acute liver failure cases are due to unintended chronic overdoses.³

Acetaminophen is generally the recommended analgesic for geriatric patients, because this patient population is at greater risk for the adverse reactions associated with salicylates and NSAIDs.³ While acetaminophen is often considered to be the analgesic of choice for individuals also taking warfarin, acetaminophen can elevate an individual’s international normalized ratio; therefore, patients taking anticoagulants should be advised to avoid routine use of acetaminophen, when possible, and always consult their primary health care provider before using any OTC analgesic.³ Patients should also be advised that concurrent use of acetaminophen and alcohol can increase the risk of hepatoxicity.³

Salicylates

The maximum analgesic dose for selfmedication with aspirin is 4 g/day, however dosages of 4 to 6 g/day may be needed to produce anti-inflammatory effects.³ More than 50% of patients who take aspirin experience upper GI symptoms.³ Individuals with risk factors for upper GI bleeding should avoid the use of aspirin, as well as individuals on anticoagulants and those with hepatic and renal disorders or heart failure.³

Aspirin and other salicylates should never be used in patients aged 15 years and younger who are recovering from the chickenpox or influenza.³ The use of aspirin, unless otherwise directed by a physician, should be avoided in those patients with gout or diabetes. Patients with renal impairment should consult their primary health care provider prior to using aspirin or other salicylates.³

The use of aspirin is associated with several clinically significant interactions with certain drugs, including valproic acid, beta-blockers, ACE inhibitors, diuretics, anticoagulants, methotrexate, and sulfonylureas.³

Conclusion

Patient education is crucial to ensuring that OTC analgesics are used appropriately and safely. Pharmacists should encourage patients with preexisting medical conditions—including pregnant and lactating women—to consult their physician prior to using any of these products. Patients with asthma or nasal polyps or a history of hypersensitivity to aspirin or other NSAIDs should not use these products.³

It is imperative for pharmacists to remind patients to adhere to the recommended dosages and duration of use unless otherwise directed by a physician, as well as the warnings listed on the manufacturer product labels. Prior to taking any medications, especially combination products, patients should read all labels to avoid the possibility of unnecessary drug use or therapeutic duplications.

Patients should also be reminded to not drink alcohol when using these agents. Patients who are not achieving adequate pain relief after using OTC analgesics should be referred to their primary care physician for further evaluation.

For more information on the safe use of OTC analgesics, visit the FDA Web site at: www.fda.gov/Drugs/resourcesForYou/Consumers/BuyingUsingMedicineSafely/UnderstandingOver-the-CounterMedicines/SafeUseofOver-the-CounterPainRelieversandFeverReducers/ucm164977.htm. â– 

âžœ • For Pharmacist-recommended analgesics, go to www.OTCGuide.net.

References

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Davidow L. Self Care and Nonprescription Pharmacotherapy. In: Berardi R, Newton G, McDermott JH, et al, eds. Handbook of Nonprescription Drugs 16th ed. Washington, DC: American Pharmacists Association; 2009: 1-2.

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Frederick AM, Pan DE, Johnson GE. OTC analgesics and drug interactions: clinical implications.Osteopath Med Prim Care

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2008 Feb 7;2:2.

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Remington T. Headache In: Berardi R, Newton G, McDermott JH, et al, eds. Handbook of Nonprescription Drugs 16th ed. Washington, DC: American Pharmacists Association; 2009:65-81.

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Joint Meeting of the Drug Safety and Risk Management Advisory Committee with the Anesthetic and Life Support Drugs Advisory Committee and the Nonprescription Drugs Advisory Committee Meeting Announcement. Food and Drug Administration website. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2009/ucm149573.htmAccessed January 2, 2010.

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Antman EM, Bennett JS, Daugthery A. Use of nonsteroidal anti-inflammatory drugs: an update for clinicians. Circulation 2007; 115:1634-42.