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Keywords:

  • over-the-counter;
  • paracetamol;
  • self-medication;
  • suitability

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Declarations
  8. References

Objectives  This study examines awareness of the potential risks associated with over-the-counter (OTC) use of paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs) among Australian consumers to better understand patterns of usage of these products.

Methods  We employed two self-reported cross-sectional surveys (conducted in 2001 and 2009) using computer-aided telephone interviewing. Both survey samples were weighted to match national population proportions; data were collected for 3702 respondents (study 1, 2001, n = 1901; study 2, 2009, n = 1801). The inclusion criteria were age over 18 years and willingness to participate in the survey.

Key findings  Self-reported regular use (once or more per month) of OTC analgesics declined between 2001 (67.5%) and 2009 (55.0%; P < 0.05). In 2009 42.0% of regular OTC analgesic users were purchasing NSAIDs outside the pharmacy setting (compared with none in 2001). Stated awareness of potential risks has increased slightly among regular paracetamol users (from 49.0% in 2001 to 52.0% in 2009) and regular NSAID users (from 25.0% in 2001 to 41.0% in 2009). Regular OTC analgesic users were considered to be using the product appropriately if there were no contraindications, warnings, precautions or potential drug interactions to the analgesic that they had used. In 2001, significantly more people were using paracetamol appropriately than were using NSAIDs appropriately (98.3 compared with 79.3%; P < 0.05). Corresponding figures for 2009 were 96.4 and 69.1% (P < 0.5).

Conclusions  Increasing consumer awareness of the need to consider potential risks prior to taking OTC analgesics is a positive sign. However, this has not translated to an increase in appropriate use of OTC NSAIDs; since ibuprofen has become available outside the pharmacy setting in Australia fewer people are using NSAIDs appropriately according to the label. The quality use of medicines, in particular OTC NSAIDs, is becoming increasingly reliant on product labelling and the ability of consumers to understand and self-assess risk.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Declarations
  8. References

In the midst of escalating healthcare costs globally, self-medication has become an increasingly important option in the symptomatic management of common conditions. Self-medication encourages consumers to take an active role in their health. Self-medication also provides positive outcomes at a societal level. The total annual savings resulting from a move of 5% of prescribed medications to self-medication in seven European countries has been estimated to be in excess of €16 billion.[1] However, the benefits of such self-medication practices are dependent upon their being undertaken responsibly.

Global research, spanning 50 countries, into consumers' attitudes towards key aspects of self-care revealed that 95% of respondents were open to taking medicines to self-treat minor ailments.[2] Although safety and efficacy were deemed the most important product attributes, there was no clear global consensus on the way in which consumers can best ensure they use self-medication appropriately. Responsible self-medication is driven largely by two aspects of drug safety: the intrinsic characteristics of the drug and how the drug is used. Appropriate use depends upon the availability of information, and how easily it can be used.

Within the broader context of self-medication, pain relief occupies a prominent position. The analgesic paracetamol was the first drug to be made available over the counter (OTC) in modern times.[3,4] Today analgesics represent one of the leading self-medication categories. In 2008 in Europe consumers spent €4193 million on analgesics, amounting to 14% of the total non-prescription market. Corresponding figures for the USA and Australia were €2021 million (US$2768 million; 16.5% of the total non-prescription market) and €223 568 (AUS$338 583; 8.5% of the total non-prescription market), respectively.

Differences in regulatory classification systems in different countries mean that the term ‘OTC analgesic’ defines analgesics that are available within the pharmacy setting without a prescription as well as those that are available in general sales outlets where no healthcare professional intervention is readily available. In the Australian market paracetamol was first introduced in 1956 and has been available in general sales outlets for several decades. By contrast, the oral non-steroidal anti-inflammatory drugs (NSAIDs) ibuprofen, naproxen and diclofenac have each been available in pharmacies without a prescription since 1989, 1990 and 1997, respectively, but only ibuprofen has been switched to general sales status (in 2004).

This paper assesses awareness of the benefits and harms associated with OTC use of paracetamol and NSAIDs (predominantly ibuprofen) among Australian consumers to better understand how consumers are using these products. The data were collected at two time points, allowing interpretation of the impact of changes in scheduling status of oral ibuprofen from within the pharmacy to general sales. Through a greater understanding of consumer beliefs we aim to gain insight into how to maximise the benefits and minimise the risks of OTC analgesic use.

Methods

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Declarations
  8. References

Two cross-sectional self-report surveys were conducted (survey 1 in 2001 and survey 2 in 2009) by a commercial market research provider (The Leading Edge, Sydney, Australia). In both surveys, eligible subjects were drawn from a nationally representative and randomly selected sample of men and women aged 18 years or over who reported ever having used an OTC pain reliever.

For each study, a minimum sample size of 1000 participants was sought to ensure a representative sample. Weighting for age, gender and location was applied to adjust each sample to accurately reflect the natural population distribution. In 2001 the initial sample was drawn from Oz on Disk (United Directory Systems) whereas in 2009 participant selection was undertaken via random-digit dialling. In the 2009 survey, bad numbers (numbers that were either disconnected or incomplete), dead numbers (no dial tone), unanswered numbers (numbers dialled more than four times without a contact) and inactive numbers (inappropriate time to call such as on a public holiday) were removed from the total initial random sample of numbers. In both surveys, among the answered numbers, potential participants who either declined to participate at any stage or who did not meet the inclusion criteria (i.e. who were not aged 18 years or over) were excluded.

Eligible participants completed a computer-aided telephone interview, which was administered in English only. Both questionnaires were divided into five main sections: (1) screening questions (to determine study eligibility), (2) information regarding current/past medical conditions and medications taken to manage them, (3) use of pain relievers and pain-reliever-purchasing behaviour, (4) awareness of risks associated with different analgesic compounds and (5) demographics. All respondents were asked to answer sections 1, 2 and 5; sections 3 and 4 were asked only if the respondent had indicated regular analgesic use (analgesics used at least once a month). The questionnaires can be supplied upon request to the corresponding author. The data were collected in accordance with Australian National Privacy Guidelines; no identifying data were collected and prior ethics committee review was not undertaken per guidance in the National Statements on Ethical Conduct in Human Research.[5,6]

The primary outcome measures were the prevalence of use of OTC analgesics, the proportion of people with contraindications, warnings or precautions for use of OTC analgesics, the potential for drug–drug interactions and the potential for taking more than one product with the same active ingredient. These outcome measures provided an indirect means of assessing patterns of analgesic usage and potential for misuse of analgesics. Prior research has shown that paracetamol is more suitable for use in a larger proportion of the general population than is ibuprofen.[7] Using a similar methodology, a suitability rate was calculated for regular OTC analgesic users (the proportion of regular OTC analgesic users with no current contraindications, warnings or precautions or potential drug–drug interactions to the analgesic that they had used). The criteria used to determine analgesic suitability are listed in Table 1. Statistical comparisons were performed to determine whether the suitability rate was different between paracetamol and NSAIDs and whether it had changed between the two studies. Participants' responses were summarised and chi-square analysis performed to identify significant differences between groups. All data analyses and statistics were performed using SPSS software (version 15.0; SPSS, Chicago, IL, USA).

Table 1.  Screening criteria used to determine suitability rate among regular users of over-the-counter paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs)
 Medical condition: warning or contraindicationMedical condition: precautionConcurrent medication: drug interactions
Paracetamol Renal impairmentAnticoagulant therapy (warfarin)
Hepatic impairment 
NSAIDsGastric or duodenal ulcer/bleedingRenal impairmentAnticoagulant therapy (warfarin)
Pregnancy (third trimester)Hepatic impairmentAspirin
 AsthmaNSAID
 Gastrointestinal problems (unspecified)Angiotensin-converting enzyme inhibitors
 Allergic reaction to aspirin or other NSAIDAngiotensin II receptor antagonist (AIIRA)
 Pregnancy – first 6 monthsβ-Blocker
  Diuretic
  Combination anti-hypertensive agent

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Declarations
  8. References

Data were collected for 3702 respondents (2001 survey, n = 1901; 2009 survey, n = 1801). Table 2 provides a detailed breakdown of the samples for each survey. Analgesic use remains prevalent in Australia; 85.0% of respondents reported using an OTC analgesic at least once a year (2001, 1618/1901; 2009, 1545/1801). Regular use declined from 67.5% (1283/1901) in 2001 to 55.0% (993/1801) in 2009 (P < 0.05). Regular users of analgesics were more likely to be female (2001, 731/1283, 57.0%; 2009, 566/993, 57.0%), irrespective of compound usage.

Table 2.  Sample sizes utilised in the 2001 and 2009 surveys
  n (%)
Total sampleRemovedDeclinedExcluded (age <18 years)Analysed
  • *

    Bad numbers = 40 474, dead numbers = 10 547, unanswered numbers=9101, inactive numbers = 1062.

2001 survey (Oz on Disk)17 420 (100)N/A12 151 (69.8)3368 (19.3)1901 (10.9)
2009 survey (random-digit dialling)82 852 (100)61 184* (73.8)13 541 (16.3)6326 (7.7)1801 (2.2)

Among regular users of OTC analgesics, significant changes in the compound last used occurred between the two surveys (Figure 1). In both surveys, ibuprofen accounted for more than 99.0% of the reported total NSAID use. The proportion of people reporting using an OTC NSAID increased from 11.0% (141/1283) in 2001 to 26.0% (258/993) in 2009 (P < 0.05). Purchasing habits changed significantly between 2001 and 2009; in 2001 NSAIDs were not available outside the pharmacy setting but in 2009 42.0% (87/206) of regular OTC NSAID users purchased this product in a general sales environment and of those who did purchase an OTC NSAID in the pharmacy 41.0% (45/109) self-selected the product.

image

Figure 1. Over-the-counter analgesic used on last occasion in 2001 and 2009. Regular analgesic users are those who reported using one or more over-the-counter analgesic per month. NSAID, non-steroidal anti-inflammatory drug.

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More people under the age of 54 years reported regular use of OTC analgesics than did those aged 55 years or more, with a higher proportion of these respondents using NSAIDs than paracetamol (Figure 2). Regular use of paracetamol was significantly higher than that of NSAIDs in respondents aged 65 years or more in 2001 and in 2009 (P < 0.05).

image

Figure 2. Age profiles of regular users of paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs) in 2001 and 2009. Regular analgesic users are those who reported using one or more over-the-counter analgesic per month.

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Patterns of analgesic usage

There were no significant changes in reported usage of OTC analgesics between the 2001 and 2009 surveys. In 2009, the number of tablets taken each day, as reported by regular paracetamol users, was within the labelled maximum doses. No paracetamol users reported taking more than eight tablets per day, whereas 3.0% (8/260) NSAID users reported taking more than six tablets per day (the maximum OTC dose for 200 mg ibuprofen tablets). The average daily dose taken was 3.0 tablets (paracetamol users) and 2.9 tablets (NSAID users) and the average frequency was 1.6 times per week (paracetamol users) and 1.4 times per week (NSAID users).

The potential for taking more than one product with the same active ingredient has been assessed by determining whether regular paracetamol and NSAID users also reported taking other medications that contain these active ingredients around the same time. In 2009, 18.9% (118/624) of regular paracetamol users reported having used other medications containing paracetamol and 22 of these were taking a prescription paracetamol product. Similarly, 7.5% (20/260) of regular NSAID users reported having used other medications containing ibuprofen and two of these were taking a prescribed NSAID. These figures represent non-significant increases of 3.8% among regular paracetamol users and 3.5% among regular NSAID users since the 2001 survey. Among the 118 regular paracetamol users, only four had stated that they had taken a daily dose of more than six 500 mg paracetamol tablets at that time; one respondent reported taking seven 500 mg tablets (3500 mg/day) and three reported taking eight 500 mg tablets (4000 mg/day) but none reported taking more than eight tablets.

Awareness of potential risks

Awareness of potential risks has increased among regular OTC analgesic users (Table 3). In the 2009 survey 51.9% (516/993) stated that they were aware of the potential risks associated with paracetamol and 41.1% (383/993) were aware of the potential risks associated with NSAIDs. By comparison in 2001, stated awareness of potential risks was lower: 49.0% (629/1283) and 25.0% (321/1283) for paracetamol and NSAIDs, respectively. Similarly, awareness of true potential risks (determined via a correlation of respondents' verbatim stated risks with the warnings, precautions and contraindications listed in the prescribing information) was higher in 2009; for paracetamol 35.0% (348/993) in 2009 up from 33.0% (424/1283) in 2001 and for NSAIDs 31.0% (308/993) in 2009 up from 20.0% (257/1283) in 2001. In both studies, respondents displayed a level of understanding that too much paracetamol can be harmful (2001, 19.0%, 244/1283; 2009, 21.0%, 209/993). Knowledge of the need to consider current or previous gastrointestinal conditions prior to NSAID use increased significantly from 13.0% (167/1283) in 2001 to 22.0% (219/993) in 2009 (P < 0.05). Similarly there was a significant increase in the appreciation of hepatic impairment as a precaution for paracetamol use, from 11.0% (141/1283) in 2001 to 17.0% (169/993) in 2009 (P < 0.05). In 2009 fewer regular NSAID users correctly identified that NSAIDs should be used with caution in people with asthma: 3.8% (10/260) compared with 6.8% (87/1283) in 2001.

Table 3.  Proprotion of respondents who were aware of potential risks associated with taking over-the-counter analgesics
 20012009Change
  • All values are expressed as percentages.

  • NSAID, non-steroidal anti-inflammatory drug.

  • *

    Statistically significant (P < 0.05) change from 2001.

Aware of potential risks associated with paracetamol use49.0%51.9% inline image2.9%
Aware of potential risks associated with NSAID use25.0%41.1% inline image16.1%*
Aware that too much paracetamol can be harmful19.0%21.0% inline image2.0%
Aware of the need to consider gastrointestinal conditions prior to taking an NSAID13.0%22.0% inline image9.0%*
Aware of hepatic impairment as a precaution for paracetamol use11.0%17.0% inline image6.0%*
Aware of the need for caution when using NSAIDs in people with asthma6.8%3.8% inline image3.0%

Medical conditions

Regular analgesic users also provided information about their current and past medical conditions. Based on the compound last used, a higher proportion of NSAID users were likely to either currently or previously have been affected by a medical condition that posed a contraindication, warning or precaution to the use of that compound compared to paracetamol users (Table 4). The proportion of respondents with a medical condition (current or previous) that is listed as a contraindication, warning or precaution to NSAID use increased significantly from 2001 to 2009 (Table 4). There was no significant increase among the paracetamol users. Overall, the suitability rate was significantly higher among paracetamol users than for NSAID users in both 2001 (98.3 compared with 79.3%; P < 0.05) and 2009 (96.4 compared with 69.1%; P < 0.05; Figure 3).

Table 4.  Proprotion of respondents with warnings, contraindications or precautions, or taking medications that might interact with their over-the-counter analgesic
 Warning or contraindicationPrecautionPotential interaction with a medication currently being takenTotal with current warning, precaution, contraindication or interaction
With a current conditionEver had a conditionWith a current conditionEver had a condition
  • All values are expressed as n (%).

  • *

    Indicates the analgesic used on the last occasion among the respondents who regularly use over-the-counter analgesics (once or more per month).

  • Significantly different (P < 0.05) from paracetamol users.

  • Significantly different (P < 0.05) from 2001.

Paracetamol users*      
 2001 (n=773)0 (0.0)0 (0.0)8 (1.0)30 (3.8)5 (0.7)13 (1.7)
 2009 (n=624)0 (0.0)0 (0.0)12 (1.9)38 (6.1)11 (1.7)23 (3.6)
NSAID users*      
 2001 (n=255)3 (1.2)13 (5.1)11 (4.3)59 (23.1)39 (15.2)53 (20.7)
 2009 (n=260)6 (2.3)23 (8.8)39 (15.0)110 (42.3)35 (13.6)80 (30.9)
image

Figure 3. Suitability rate among regular users of over-the-counter (OTC) paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs). Data based on the OTC analgesic that the respondent reported using on the last occasion. The suitability rate is the proportion of regular OTC analgesic users with no current contraindications, warnings or precautions, or potential drug–drug interactions, to the analgesic that they had used. All data derived from Table 3.

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Regular analgesic users also provided information about current use of other medications. In 2009, based on the compound last used, 13.6% (35/260) of regular NSAID users reported taking another, concurrent, medication that might put them at increased risk of drug–drug interactions or adverse events; 1.6% fewer than in 2001. In 2009, 7.5% (20/260) of regular NSAID users were using another NSAID [OTC (n = 18) or prescribed (n = 2)] concurrently with OTC ibuprofen, 4.4% (12/260) were also taking antihypertensive medications and 1.3% (3/260) were also taking combination antihypertensive agents. The proportion of people at risk of potential drug–drug interactions was significantly lower among regular paracetamol users than regular NSAID users (Table 4).

The medical conditions that were most frequently implicated as making the analgesic use potentially unsuitable were asthma and gastrointestinal complications (NSAID users) and liver and renal disease (paracetamol users). In 2009, 10.0% (26/260) of regular NSAID users stated that they had currently diagnosed asthma and 25.0% (65/260) stated that they had ever been diagnosed with asthma, an increase from 3% (8/255) and 15% (38/255), respectively, in 2001. Similarly, in 2009, 6.2% (16/260) of regular NSAID users had currently diagnosed gastrointestinal conditions (compared with 2.3%, 6/255, in 2001) and 23.1% (60/260) had ever been diagnosed with a gastrointestinal condition (compared with 11.0%, 28/255, in 2001). Among the 624 regular users of OTC paracetamol, six (1.0%) reported currently having liver disease and 13 (2.0%) reported ever having had this condition. By comparison, in 2001 no regular paracetamol user reported current liver disease and 15 (2.0%) reported ever having had liver disease.

Analgesic use in pregnancy

At the time of the 2009 survey, 78 women were pregnant, breastfeeding or trying to conceive. Almost two-thirds (48, 61.5%) of these women were categorised as regular OTC analgesic users and, of these, 34 (70.8%) had used paracetamol on the last occasion and 14 (29.1%) had used an NSAID. By comparison, in the 2001 survey, 46 women were either pregnant or breastfeeding; 37 (80.4%) of whom had used paracetamol and nine (19.6%) of whom had used an NSAID.

In the 2009 study, specific questions were included to investigate the use of NSAIDs before and during pregnancy. Among regular analgesic users (n = 933) there were 366 females aged 18–49 years. Almost one-third of these females (31.1%, 114/366) claimed to be aware of potential risks associated with NSAID use at any time during pregnancy and 73 (19.9%) claimed to be aware of potential risks of taking ibuprofen while trying to conceive. The findings were similar among those respondents who had used an NSAID on their last pain occasion (n = 126): 47 (37.3%) claimed awareness of risks at any time during pregnancy and 25 (19.8%) were aware of risks when trying to conceive.

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Declarations
  8. References

Our study has found that between 2001 and 2009 there was an overall decline in the proportion of Australian consumers who regularly use OTC analgesics at least once per month. Alongside this decline there has been a change in the type of compound used, with the use of OTC NSAIDs more than doubled. Additionally, in 2009, 42.0% of regular OTC NSAID users purchased this product in a general sales environment.

During this time period ibuprofen was made more widely available (as it was switched to general sales, thereby permitting sale in any retail outlet, including supermarkets, petrol stations and convenience stores) and a number of new codeine-combination products (including ibuprofen/codeine combinations) were launched as Pharmacy Only products. The changes observed in our study reflect how consumers adapt to changes in the non-prescription analgesics environment.

Consumer awareness of the potential risks associated with the use of OTC analgesics has increased over time. However, our results probably represent a conservative estimate since the data are based on responses from regular users who would likely have more knowledge of these compounds than infrequent users. Despite almost one in two regular users of OTC analgesics stating that they are aware of potential risks, only one-third are correctly aware of the established risks.

Overall, the suitability rate in our study was significantly higher among paracetamol users than NSAID users for both survey years. Our data show that since ibuprofen has become available outside the pharmacy setting, 10.2% fewer people are using OTC NSAIDs appropriately (i.e. increased use when they have contraindications, warnings, precautions or potential drug interactions). The quality use of medicines, in particular OTC NSAIDs, is becoming increasingly reliant on product labelling and the ability of consumers to understand and self-assess risk. Our suitability-rate data are consistent with previous patient data research conducted among Australian general practitioners.[7]

The age-interactions-medications (AIM) protocol is a simple screening tool designed to ensure appropriate use of OTC analgesics.[7] Applying the first of the principles set out in this tool (age) to our consumer data it is noteworthy that, despite the rise in OTC NSAID use, the proportion of elderly patients (aged 65 years or more) currently using these compounds is minimal (2.0%) and that paracetamol use has increased among the elderly. The increase in paracetamol use in elderly patients in 2009 compared with 2001 does not appear to reflect an increase in prescribing or purchasing; rather, it demonstrates a shift in the demographic profile of the consumer. Paracetamol has become the preferred analgesic in older consumers, whereas younger consumers appear more likely to use NSAIDs. Our data on consumers' analgesic-usage patterns are also encouraging, indicating that OTC analgesics are being used as recommended on the label, in terms of both number of tablets taken and frequency of use.

Paracetamol is associated with very few clinically significant drug interactions.[8] Despite the potential for an interaction with warfarin,[9] paracetamol remains the analgesic of choice for patients undergoing anticoagulant therapy;[10] this may explain why approximately 2.0% of paracetamol users were also taking warfarin. In contrast, the potential for drug–drug interactions with NSAIDs is higher.[11] In 2009, 4.4% of regular OTC NSAID users were concurrently taking antihypertensive medications and a further 1.3% were taking combination antihypertensive agents. This is slightly lower than has previously been reported in a sample of patients from general practice.[12] Although clinically relevant interactions are more likely with chronic and/or high-dose use of an NSAID and an interacting drug,[13] the potential negative public health implications of these interactions should not be ignored.

Paracetamol is well tolerated when taken at the recommended dose (up to 4000 mg/day); data from prospective studies (involving more than 30 000 patients) have shown that repeated use of a true therapeutic paracetamol dosage is not associated with hepatic failure.[14] However, it is accepted in the literature that an acute single ingestion of 10 g of paracetamol may be associated with hepatic injury and could warrant referral for examination.[15] Therefore it is important for consumers to understand the need to keep to the recommended dose and to not take more than one product containing paracetamol at a time.

In our survey, 18.9% of regular paracetamol users reported that they had taken another medication containing paracetamol at around the same time as having taken a paracetamol-containing analgesic. The survey question was structured such that the use of the cold and flu medication did not have to occur at the same time or even on the same day, just around the same time. This limits the ability to determine whether true ‘doubling-up’ of products had occurred. As such, among regular paracetamol users it is unknown whether there was concurrent dosing of two or more paracetamol-containing products or whether the maximum daily paracetamol dose was being exceeded. However, based on our finding that only three of the respondents who reported taking two products at around the same time had taken the maximum daily dose of paracetamol, and none had exceeded it, the potential for therapeutic misadventure is very small. However, this does highlight the importance of educating consumers to check the active ingredients in cold and flu products if they are already taking paracetamol for analgesia.

Whereas in 2009 more respondents were aware of the need to consider gastrointestinal conditions prior to using an NSAID than in 2001, it remains that almost four in five indicate no knowledge that NSAIDs are contraindicated in people with a current gastrointestinal ulcer and that there is a precaution if they have ever had this condition in the past. In addition, 7.5% of regular OTC NSAID users reported taking other NSAIDs concurrently, putting them at increased risk of adverse gastrointestinal events. This has substantial public health implications. It has been previously reported that when OTC NSAIDs are used according to their labelled instructions risks of adverse gastrointestinal side effects are not substantially different to those with paracetamol.[16] Importantly, however, such data are based on a population that excludes those with current or prior gastrointestinal disorders.[17] Within our sample, 23.1% of regular NSAID users stated that they either currently had or had previously had gastrointestinal problems. It is this group that are most at risk and who require education to ensure that they are aware of these risks when selecting OTC NSAIDs and of the need to not double up on NSAID usage.

Aspirin-induced asthma can affect up to 20% of the adult population with asthma.[18] It usually first appears around the age of 30,[19,20] and women are often affected more than men.[21] It is under-diagnosed as the reaction is often is not attributed to the use of an analgesic.[19] Almost all patients whose asthma can be triggered by aspirin are cross-sensitive to other NSAIDs.[22] One in ten NSAID users reported either currently having asthma, and one in four had ever had asthma, yet only 3.8% were aware of the need for caution with NSAIDs.

There is epidemiologic evidence suggesting an association between early paracetamol exposure (either prenatally or in early infancy) and subsequent asthma.[23–28] A causal link between the use of paracetamol and asthma arising later cannot be established from these studies. Most recently it has been suggested that, in the absence of direct causal relationship, early drug use (paracetamol and antibiotics) and later asthma are associated due to confounding though the infection node.[29] Supporting this, there is a growing body of evidence linking early childhood infections with the risk of asthma.[30–32] Furthermore, prospective cohort studies have found that paracetamol use during pregnancy[33] or in early infancy[34] did not increase the subsequent risk of asthma. While this topic continues to generate much clinical and media interest, it has been suggested that a change from paracetamol to NSAIDs in pregnancy might have other associated risks.[35]

US[36] and UK[37] data suggest that a high proportion of pregnant women self-medicate minor ailments with OTC medications. In the Sloane Epidemiology Center Birth Defects Study a total of 7563 mothers of offspring with and without birth defects were interviewed between 1998 and 2004, showing that 69.8% had used paracetamol and 24.8% had used ibuprofen.[36] Similarly, in the National Birth Defects Prevention Study, conducted among a total of 2970 mothers, rates of use were 65.5% and 18.4%, respectively.[36] Our findings are consistent with these earlier reports; among respondents who were pregnant and regular analgesic users paracetamol was used by 71.0% and ibuprofen by 29.0%. The predominant use of paracetamol reflects its category A pregnancy status, defined in Australia as drugs which have been taken by a large number of pregnant women and women of childbearing age without an increase in the frequency of malformations or other direct or indirect harmful effects on the fetus having been observed.[38]

More than half of all pregnancies are unplanned, potentially exposing many women to various agents that may have a harmful effect on the foetus during the critical first few weeks of gestation.[39] Studies have suggested an association between the use of NSAIDs very early in pregnancy and an increased risk of miscarriage,[40–43] whereas others demonstrate an association between the use of NSAIDs and luteinising un-ruptured follicle syndrome causing transient infertility.[44–47] Use of NSAIDs is contraindicated during the third trimester of pregnancy. In Australia it has also been mandated, since 2008, that products containing ibuprofen display a package warning stating that the product should not be used during the first 6 months of pregnancy, except on a doctor's advice. Nevertheless, among females aged 18–49 years in our study, only 31% claimed to be aware of any risk of taking ibuprofen during pregnancy and 20% indicated any awareness of potential risks associated with using ibuprofen when trying to conceive.

Consumer research data are not without limitations and there is often concern that reliable results cannot be achieved in telephone surveys. Although both studies included a large sample size, the data provide only a cross-sectional snapshot in time of consumers' self-reports and may be subject to respondent recall bias. Additionally, although the questionnaire was specific to the use of analgesics that were purchased without a written doctor's prescription, our data are silent on such topics as duration of use and whether use of the analgesic purchased OTC was recommended by a healthcare professional. A prospective cohort study evaluating consumers' habits, with specific data regarding dosing and concomitant drug usage, may provide further insight into the true risks of real-world use of OTC analgesics.

Our study focused primarily on the suitability of single active ingredient analgesics; however, a number of fixed-dose combination analgesics are available in the OTC setting. From a suitability perspective their use requires even more care, making it important to ensure that consumers are aware of the potential risks associated with both active ingredients when selecting these products.

Our research found no significant public health issues associated with the OTC use of paracetamol, but it has shown that up to three in 10 regular users of OTC NSAIDs have current or prior medical conditions that warrant discussion with a healthcare professional prior to their use. It is important to note that some of these consumers may already be acting upon such advice, reducing the potential risk. However, with a large proportion of regular users of OTC NSAIDs purchasing these products outside the pharmacy setting, the quality use of OTC NSAIDs is becoming increasing reliant on product labelling and the ability of consumers to understand and self-assess their own level of risk.

A key theme emanating from our data and from other recent changes in the analgesics landscape both locally and globally is the continued need to ensure a high level of consumer education regarding the appropriate choice and use of analgesics. For the vast majority of consumers who have used these medications in the past the potential risks are minimal. However, consumers need to be aware that if their health status changes then this warrants a discussion with a healthcare professional to confirm the continued appropriateness of their OTC analgesic medication. Rather than placing the onus solely on the consumer to actively seek advice and hoping that this is undertaken a more practical approach would be to also reinforce with healthcare professionals the need to proactively probe patients about the use of OTC analgesics and offer advice as to any changes that need be undertaken when they present with a new condition that puts them into an at-risk population. The safe and effective use of any OTC medication requires active participation and open communication between the user and healthcare professionals.

Conclusion

Our study demonstrates that since ibuprofen has become available outside the pharmacy setting in Australia fewer people are using NSAIDs appropriately according to the label; compared to 2001, in 2009 10.2% more regular OTC analgesic users were using ibuprofen despite having contraindications, warnings, precautions or potential drug-interactions. The increasing use and wider availability of OTC NSAIDs may have led to a more relaxed attitude regarding the use of these medicines. Although we also found an increase in consumer awareness of the need to consider potential risks prior to taking any OTC analgesic, self-care choices may not always be optimal and under appreciation of the potential risks remains a challenge to optimising responsible self-medication. Continued effort to raise consumer awareness and to facilitate more informed individual treatment choices is warranted. Healthcare professionals continue to play an important role by proactively probing patients about the use of OTC medications, particularly when a new diagnosis has the potential to impact on patients' choice of such medicine.

Declarations

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Declarations
  8. References

Conflict of interest

This work has been carried out with financial support from GlaxoSmithKline Consumer Healthcare. GlaxoSmithKline Consumer Healthcare manufactures and markets over-the-counter analgesics, including paracetamol, ibuprofen and fixed-dose combination products.

Funding

Drs Rodney Stosic and Fiona Dunagan and Mr Ian Adams are employees of GlaxoSmithKline Consumer Healthcare Australia. Hazel Palmer is an employee of Scius Solutions Pty Ltd; this company has received funding from GlaxoSmithKline Consumer Healthcare with respect to the work undertaken. Trafford Fowler was an employee of The Leading Edge Pty Ltd during the fieldwork and the writing of this manuscript; this company has received funding from GlaxoSmithKline Consumer Healthcare with respect to the work undertaken. GlaxoSmithKline Consumer Healthcare reimbursed The Leading Edge Pty Ltd for their time in preparing and executing the questionnaires and undertaking raw data analysis.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Declarations
  8. References