Acute pain management with over-the-counter (OTC) analgesics

Introduction

Achieving adequate pain relief in the community setting has become increasingly challenging. Misuse of analgesics in recent years has led to the implementation of stricter regulations in Australia, from the upscheduling of codeine to the more recent interim decision on changes to paracetamol scheduling.^1-3

These measures may have disrupted access to some pain management options for patients, which may be contributing to the undertreatment of pain.^1,2

Inadequate management of acute pain may result in the worsening of pain, more frequent hospital readmissions, and added economic burden associated with pain therapy.⁴ It may also reduce quality of life, impair sleep and physical function, and potentially increase the risk of transition to chronic pain.^4,5 Supporting evidence from an inception cohort study alongside a multi-site, pragmatic, cluster randomised clinical trial in the United States showed almost a third of patients with acute low back pain transitioned to chronic pain at 6 months (32%; n = 1666/5233).⁶

Pain management requires a multimodal approach of non- pharmacological strategies alongside adequate analgesia⁷ – not so little that pain is uncontrolled, but not so much as to be problematic. In acute pain, over-the- counter (OTC) analgesics play a key role in achieving this⁸; pharmacists thus have a responsibility to optimise patients’ use of the available options to help ensure adequate pain control.

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Stepwise management of acute pain

Rather than eliminating pain, the primary goal of acute pain management is to facilitate return to normal functioning and prevent progression to chronicity.^5,8 Best practice utilises both non- pharmacological and pharmacological interventions, with the management strategy determined by the cause of pain, pain type(s) and pain intensity (Table 1).^7,8

Non-pharmacological interventions should always be incorporated as a foundation for acute pain management.⁹

This includes:

• Educating the patient about their condition and treatment; this can enhance expectation management and improve adherence otc treatment strategies.⁹
• Basic psychological techniques such as active listening and targeted reassurance; this can also assist with treatment adherence and reducing medication use.^9,10
• Physical interventions such as thermotherapy, massage, splinting, physiotherapy, etc; these alone may provide adequate pain relief for mild acute presentations.⁹

Pharmacotherapy may be added as necessary, with OTC NSAIDs or paracetamol as first-line options.⁷ A body of evidence indicates the proportion of patients who can achieve good analgesia (at least 50% relief) with OTC analgesics has ranged from around 70% at best to less than 20% at worst.¹¹

Optimising the use of OTC analgesics

When determining the most appropriate analgesic for a patient, the pain intensity and type should be taken into consideration, in addition to the underlying condition, comorbidities, potential interactions with other medications the patient is using, and precautions/contraindications relating to the analgesic.⁷ Recommendations from evidence-based clinical guidelines should also be considered.

Pain intensity

It is essential that the choice of analgesic adequately addresses the intensity of pain. If pain is undertreated, the patient may experience residual pain which may impact return to normal functioning^4,8 and potentially lead to repeated supratherapeutic ingestion and overdose.¹²

For patients experiencing mild to moderate pain, monotherapy with paracetamol or NSAIDs is a suitable option for those without precautions or contraindications.⁷ A wide range of dosages, formats and formulations are available to tailor treatment to a patient’s individual needs (Table 2). 

For patients experiencing moderate-to-severe acute pain, a combination of NSAID and paracetamol may be suitable.^7,23 Combining analgesics with different mechanisms of action may provide greater efficacy than monotherapy.^7,23 Fixed-dose combinations available OTC in Australia include ibuprofen 200 mg/paracetamol 500 mg and ibuprofen 150 mg/ paracetamol 500 mg. In a study comparing the efficacy and tolerability of fixed-dose combinations of ibuprofen/paracetamol (100/250 mg,* 200/500 mg and 400/1000 mg*) with comparable doses of ibuprofen (200 or 400 mg) or paracetamol (500 or 1000 mg) monotherapy and placebo for moderate-to-severe postoperative dental pain, ibuprofen 200 mg/paracetamol 500 mg demonstrated significantly more effective pain relief than paracetamol 1000 mg (p<0.001), and comparable tolerability to the single actives.²³

Table 1 – Management strategies for acute pain based on pain intensity⁷

Adopted from Therapeutic Guidelines. Pain and analgesia. 2020.⁹ NSAID, non-steroidal anti-inflammatory drug.

Pain type 

Consider the underlying cause of the pain and how pharmacotherapy may address it. For example, NSAIDs exert analgesic and anti-inflammatory effects through inhibition of cyclooxygenase and prostaglandin synthetase,²⁴ while paracetamol is thought to act via inhibition of central prostaglandin synthesis and modulation of inhibitory descending serotonergic pathways.¹³ Since paracetamol’s anti-inflammatory effects are negligible,¹³ NSAIDs are considered a more suitable option for pain with an inflammatory component. ^7,24 This is reflected in the clinical guidelines for several common musculoskeletal conditions where inflammation is implicated, such as osteoarthritis and low back pain.^25-30 For these two indications, oral NSAIDs are recommended first-line.^29,30

Table 2 – Monotherapy OTC analgesics available in Australia

Safety and tolerability

Examination of published Cochrane reviews evaluating the efficacy of 21 different OTC analgesic drugs, doses and formulations using data from acute postoperative pain indicates that adverse events with evaluated analgesics (including paracetamol, ibuprofen, diclofenac, naproxen and aspirin) are generally no different from placebo.¹¹ However, concerns are often expressed regarding the gastrointestinal (GI) safety of NSAIDs. While some international recommendations encourage NSAIDs to be taken with food to minimise GI side effects, the evidence for food modifying the GI effects of NSAIDs is lacking.^31,32

On the contrary, food may delay the absorption and impact the efficacy of NSAIDs.³² Amongst non-selective NSAIDs, ibuprofen has been found to have a low risk of developing GI adverse events, with lower doses associated with a lower risk.^33,34 In patients without contraindications or precautions, OTC doses of ibuprofen can be considered a well-tolerated option for acute pain relief without the need to be taken with food.^14,31-35

Knowledge to practice 

Once an appropriate medication is chosen, ensuring patients understand the type of analgesic they are taking is important to ensure its safe use and reduce the risk of overdose.

This includes educating them on what the active ingredients are (and which other products are of the same analgesic class, and thus should not be taken concurrently), how the medicine works, and the appropriate dosing and duration.

Setting realistic expectations is also an important risk mitigation strategy. It is important to ascertain patient beliefs and expectations about their condition and treatments and address any incorrect expectations which may lead to harmful behaviours, such as taking higher doses of medication in attempts to eliminate pain.¹⁰ Expectation management can also help to minimise reliance on medications and increase engagement with functional strategies such as exercise.¹⁰

Key points 

• Inadequate management of acute pain affects quality of life, sleep and physical functioning, and may increase the risk of transitioning to chronic pain.^4,5
• Management of acute pain should take a multimodal approach incorporating both non-pharmacological and pharmacological strategies.⁷
• The recommendation of OTC analgesics should be tailored to suit the patient’s specific needs and circumstances, taking account of precautions and contraindications. This may mean recommending paracetamol monotherapy, NSAID monotherapy (particularly for pain with an inflammatory component), or a combination of paracetamol and an NSAID for moderate acute pain.^7,23,24
• Mitigate the risk of undertreatment and/or overdosing with OTC analgesics using strategies such as setting expectations, patient education and counselling on appropriate medication use.^9,10

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References

1. Mishriky J, Stupans I, Chan V. The views of Australian adults experiencing pain on the upscheduling of codeine-containing analgesics to ‘prescription only’. Int J Clin Pharm 2021;43(2):386–93.
2. McCoy J, Bruno R, Nielsen S. Attitudes in Australia on the upscheduling of over-the-counter codeine to a prescription-only medication. Drug Alcohol Rev 2018;37(2):257–61.
3. Therapeutic Goods Administration. Public notice of interim decisions on proposed amendments to the Poisons Standard – ACMS#40, ACCS#35, Joint ACMS-ACC#32 – November 2022. 2023. At: tga.gov.au/sites/default/files/2023-02/public-notice-of-interim-decisions-acms-40-accs-35-joint-acms-accs-32-november-2022.pdf
4. Sinatra R. Causes and consequences of inadequate management of acute pain. Pain Med 2010;11(12):1859–71.
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6. Stevans JM, Delitto A, Khoja SS, et al. Risk factors associated with transition from acute to chronic low back pain in US patients seeking primary care. JAMA Netw Open 2021;4(2):e2037371.
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24. Australian Medicines Handbook (online). Non-steroidal anti-inflammatory drugs. Adelaide: Australian Medicines Handbook Pty Ltd; 2023 January.
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27. Mathiessen A, Conaghan PG. Synovitis in osteoarthritis: current understanding with therapeutic implications. Arthritis Res Ther 2017;19(1):18.
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29. Low back pain [published December 2020]. In: Therapeutic Guidelines. Melbourne: Therapeutic Guidelines Limited; accessed February 2023. tg.org.au.
30. The Royal Australian College of General Practitioners. Guideline for the management of knee and hip osteoarthritis. 2nd edn. East Melbourne, Vic: RACGP, 2018.
31. Rainsford KD, Bjarnason I. NSAIDs: take with food or after fasting? J Pharm Pharmacol 2012;64(4):465–9.
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33. Moore N, Pollack C, Butkerait P. Adverse drug reactions and drug-drug interactions with over-the-counter NSAIDs. Ther Clin Risk Manag 2015;11:1061–75.
34. Lewis SC, Langman MJS, Laporte J, et al. Dose-response relationships between individual nonaspirin nonsteroidal anti-inflammatory drugs (NANSAIDs) and serious upper gastrointestinal bleeding: a meta-analysis based on individual patient data. Br J Clin Pharmacol 2002;54(3):320–26.
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Our authors

Dr Cat Panwar (she/her) BSc(Hons), PhD has over 13 years of experience in health communications across a wide range of therapeutic areas. She has represented strategically and scientifically renowned healthcare agencies across the globe.

Our reviewer

JOHN BELL AM (he/him) BPharm, FPS, FRPharmS, FACPP, MSHP, FFIP, FCPA is a practitioner/teacher at the Graduate School of Health, University of Technology Sydney, and has a community pharmacy practice.

CONFLICT OF INTEREST DECLARATION: Mr Bell has been a member of advisory boards for, or provided advice to: Astellas, Astra Zeneca, Bayer, GSK, Mylan, Novartis, Nutricia, Pfi zer, Procter & Gamble and Reckitt Benckiser. He is currently a member of the international multidisciplinary Global Pain Faculty.