Chapter 7: Life with arthritis in Canada: a personal and public health challenge – Arthritis-related prescription medication use

Chapter Seven: Arthritis-related prescription medication use

Table of Contents

• Introduction
  • Analgesics (pain medication)
  • Non-steroidal anti-inflammatory drugs (NSAIDs)
  • Gastrointestinal (GI) protective agents
  • Corticosteriods
  • Disease-modifying anti-rheumatic drugs (DMARDs)
  • Biologic response modifiers
• Arthritis-related prescriptions dispensed to people with arthritis
  • Prescriptions by arthritis type
  • Prescriptions by age and sex over time
    • NSAIDs and GI protective agents
    • DMARDs
    • Corticosteriods
    • Biologic response modifiers
• Summary

Introduction

Arthritis encompasses a group of complex diseases for which there is currently no known cure. Medication is a key component of the management of arthritis in the effort to reduce pain, maintain joint function and limit disease progression.^{Footnote 1}

For some types of arthritis, particularly inflammatory conditions, early diagnosis and timely treatment is vital in order to reduce pain and inflammation, prevent or reduce disability, and to improve overall quality of life.^{Footnote 2 Footnote 3 Footnote 4 Footnote 5 Footnote 6 Footnote 7 Footnote 8 Footnote 9} Without effective treatment, the course of many forms of arthritis such as rheumatoid arthritis (RA) and ankylosing spondylitis (AS) leads to functional disability.^{Footnote 4 Footnote 8}

Currently, medications used for treating arthritis include: analgesics, non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, disease modifying anti-rheumatic drugs (DMARDs) and biologic response modifiers (also known as biologics). In recent years, the introduction of new drugs such as biologics, have greatly improved the efficacy of pharmacological treatment for arthritis. Furthermore, innovative drugs for osteoarthritis (OA) are on the horizon, including drugs to prevent the progression in the early stages of the disease and disease-modifying drugs for established OA (DMOADs).^{Footnote 10}

This chapter examines the use of arthritis-related medications by type of arthritis, age, sex, year and drug classes, using IMS Health Canada (IMS) data. The specific types of arthritis were grouped into five categories:

• Osteoarthritis (OA);
• Rheumatoid arthritis (RA);
• Other inflammatory arthritis (e.g. gout, psoriatic arthritis (PsA), ankylosing arthritis (AS));
• Connective tissue diseases (e.g. systemic lupus erythematosus, scleroderma); and
• Other arthritis conditions (e.g. polymyalgia rheumat- ica, tendonitis, bursitis, synovitis, internal derangement of the knee, other unspecified arthropathies).

Analgesics (pain medication)

Simple Analgesics include medications such as acetaminophen. While they are considered the first-line therapy for arthritis pain (predominately used in OA), they have no effect on inflammation.Footnote 1 Footnote 2 Footnote 11 This form of pain medication does not require a prescription; as a result, it is difficult to track its usage.Footnote 1 Footnote 11

Non-steroidal anti-inflammatory drugs (NSAIDs)

NSAIDs are one of the most widely used medications in the treatment of arthritis because of their painkilling (especially acute pain) and anti-inflammatory properties.^{Footnote 1 Footnote 3 Footnote 12} They are used in the treatment of most forms of arthritis, including OA, RA, gout, AS, PsA and connective tissue disorders.^{Footnote 2 Footnote 7 Footnote 11 Footnote 12 Footnote 13 Footnote 14 Footnote 15 Footnote 16 Footnote 17 Footnote 18} Some NSAIDs are available over-the-counter and some require a prescription from a physician.

Gastrointestinal (GI) protective agents

Best practice guidelines recommend that GI protective agents be prescribed to treat or prevent the GI complications (e.g. GI bleeding) associated with the use of NSAIDs among those who present with risk factors for GI problems, such as advanced age, multiple NSAIDs use or prior ulcer. GI protective agents are also prescribed for other conditions, such as Gastroesophageal Reflux Disease (GERD), primary gastro-duodenal ulcers and many stomach and bowel symptoms unrelated to the use of NSAIDs.^{Footnote 19}

Corticosteroids

Corticosteroids have successfully been used to reduce joint inflammation and disease activity in inflammatory forms of arthritis.^{Footnote 20} There are two forms of corticosteroids: oral and injectable. Both forms are effective in relieving pain and swelling for many types of arthritis.^{Footnote 1 Footnote 2 Footnote 3 Footnote 4 Footnote 5 Footnote 6 Footnote 11 Footnote 12 Footnote 13 Footnote 14 Footnote 16 Footnote 18 Footnote 21 Footnote 22 Footnote 23}

Disease-modifying anti-rheumatic drugs (DMARDs)

DMARDs are medications that suppress inflammation and prevent damage to the joint.^{Footnote 1 Footnote 4 Footnote 11 Footnote 20 Footnote 24} Currently, clinical treatment guidelines for RA recommend the initiation of DMARDs as soon as the diagnosis is confirmed. DMARDs do not have an immediate effect — relief is usually delayed. As a result, NSAIDs and corticosteroids are often used when initiating therapy with DMARDs.^{Footnote 4} DMARDs are also used in the treatment of AS, PsA, and connective tissue disorders.^{Footnote 2 Footnote 5 Footnote 7 Footnote 16 Footnote 18 Footnote 21}

Biologic response modifiers

Biologic response modifiers are the newest class of arthritis medication. Similar to DMARDs, biologic response modifiers suppress inflammation and help to prevent joint damage.^{Footnote 20} Biologic response modifiers provide symptomatic control and functional improvement in patients for whom treatment with one or more DMARDS has failed,and they are often used in combination with DMARDS.^{Footnote 11 Footnote 20}

Arthritis-related prescriptions dispensed to people with arthritis

Prescriptions by arthritis type

In 2007, over 4 million prescriptions for NSAIDs were written in Canada for individuals with a diagnosis of arthritis—the largest number among all categories of arthritis-related prescriptions. Nearly one third (30%) of NSAID prescriptions for arthritis were written for people diagnosed with OA, 9% were written for those diagnosed with RA, connective tissues diseases and other inflammatory arthritis and the remaining 61% were written for other types of arthritis such as, joint derangements, polymyalgia rheumatica, synovitis, bursitis, and unspecified arthropathies. NSAIDs can irritate the lining of the stomach and GI system. Protective drugs are prescribed to reduce the risk of irritation. Most of the GI protective agent prescriptions were either written for people with OA or for people with any of the other arthritis conditions (40% and 53%, respectively).

DMARDs are also commonly used among individuals with arthritis with over 1 million prescriptions written for people with arthritis in 2007. The majority (over 70%) of the 1 million DMARDs prescriptions were written for individuals with a diagnosis of RA. Corticosteroids prescriptions (62%) were most commonly written for those with a diagnosis that fell in the other arthritis conditions category.

Over 90% of biologic response modifier prescriptions were written for individuals diagnosed with RA.

Prescriptions by age and sex and over time

NSAIDs and GI protective agents

In 2007, more NSAID prescriptions were written for women than men with arthritis for all age groups with the exception of those between the ages of 15 and 34 years (Figure 7-1). The number of NSAID prescriptions peaked among men 45–54 years of age and among women aged 55–64 years, and then declined. These findings are in keeping with the fact that arthritis is more common among women and that the majority of individuals with arthritis are of working age.

More GI protective agent prescriptions were written for men than women with arthritis, with the exception of those aged 45–54 years and 65–74 years (Figure 7-2). There was an increase in the number of prescriptions for GI protective agents for men up to age 64 years. Whereas, there was a sharp increase in GI protective agent prescriptions among women between the ages of 35 and 54 years, followed by a steady decline thereafter.

Best practice guidelines recommend that GI protective agents be prescribed to treat or prevent the complications associated with NSAIDs use among those who present with risk factors for GI problems (e.g. advanced age, multiple NSAIDs use or prior ulcer). While a lower number of GI prescriptions were written for people with arthritis compared to the number of NSAIDs prescriptions, it is not possible to assess the potential gap between guidelines and clinical practice without knowing the proportion of individuals that presented with risk factors for GI problems.

The number of prescriptions written for NSAIDs declined over time among women and men (Figure 7-3). For women, the number of prescriptions written peaked in 2004, followed by a steep decline. The decline may have resulted from the withdrawal of Rofecoxib (a COX-2 selective NSAID) from the Canadian market in September 2004. COX-2 selective NSAIDs were specifically developed to help reduce GI complications and while successfully decreasing the risk of GI events, these agents have been associated with an increase in cardiovascular risks.^{Footnote 12} The decline may have been a result of the shift from prescription to over-the-counter use of NSAIDs.^{Footnote 25} 7-3

The number of GI protective agent prescriptions written for women and men increased greatly between 2004 and 2005, and 2005 and 2006, respectively (Figure 7-4). The sharp decrease among women between 2006 and 2007 is concerning because the number of NSAIDs prescriptions did not as sharply decrease during this time.

DMARDs

DMARDs are the primary therapy recommended for RA. The number of DMARD prescriptions written for women with arthritis was higher than for men in all age groups (Figure 7-5). This finding reflects the fact that the forms of arthritis that require treatment with a DMARD (including RA) are more common among women than men. The peak number of DMARD prescriptions was among women aged 45–64 years, after which the number began to decline; men's prescriptions peaked between 55 and 64 years of age which is consistent with the fact that the majority of individuals with arthritis are of working age.

The time trends for DMARDs prescriptions varied according to sex. The number of prescriptions written for women with arthritis increased between 2002 and 2007 while the number for men remained stable until 2006, followed by a decrease in 2007 (Figure 7-6). It is not clear why the pattern for men and women is so different.

Corticosteroids

In every age group, the number of corticosteroid prescriptions (oral and injected combined) written for women with arthritis was greater than that for men (Figure 7-7) which is in keeping with the fact that arthritis is more common among women. The number of prescriptions written for women with arthritis increased with age.

A similar trend in the number of corticosteroid prescriptions (oral and injected combined) was found among women and men: the number prescriptions written decreased between 2002 and 2004, followed by an increase from 2004 to 2006, and a subsequent decrease in 2007 (Figure 7-8).

Biologic response modifiers

Women received a higher number of written prescriptions for biologic response modifiers than men (Figure 7-9). This is in keeping with the higher prevalence of inflammatory arthritis conditions (such as RA) among women. The number of prescriptions written for women increased with age until 64 years whereas the number decreased among men within the same age groups.

The number of biologic response modifier prescriptions written for women increased sharply between both 2002 and 2003, and 2006 and 2007 (Figure 7-10). There was a sharp increase in biologic response modifier prescriptions between 2006 and 2007 for both men and women. These increases may in part be the result of changes to provincial formularies, which have increased their coverage of biologics response modifiers.

Summary

• Five main types of drugs are used to treat arthritis: analgesics, non-steroidal anti-inflammatory drugs, corticosteroids, disease modifying anti-rheumatic drugs and biologic response modifiers.
• While there has been a decrease in the use of non- steroidal anti-inflammatory drugs and corticosteroids, there has been an increase in the use of the newer drugs i.e., disease modifying anti-rheumatic drugs and biologics.
• In 2007, over 4 million prescriptions for non-steroidal anti-inflammatory drugs were written in Canada for individuals with a diagnosis of arthritis, 30% were written for people with osteoarthritis, 9% were for rheumatoid arthritis, connective tissue diseases and other inflammatory conditions and 61% were for other arthritis conditions.
• Over 1 million disease modifying anti-rheumatic drugs prescriptions were written for people with arthritis in 2007 and the majority (over 70%) were written for individuals with a diagnosis of rheumatoid arthritis.
• Close to a million corticosteroids prescriptions were written in 2007 and they were most commonly written for those with a diagnosis in the 'other arthritis' category (62%).
• In 2007, approximately 150,000 biologic response modifier prescriptions were written of which, 90% were for individuals diagnosed with rheumatoid arthritis.
• With the exception of corticosteroids, more arthritis- related drugs prescriptions were written for women than men and for those of working age than the other age groups.