Oral paracetamol and NSAIDs for osteoarthritis

Kloppenburg, 2019Kroon, 2014Sakellariou, 2017 Bannuru, 2019

The approach to managing osteoarthritis, and the role of oral paracetamol and nonsteroidal anti-inflammatory drugs (NSAIDs) for pain, is described in Components of management for osteoarthritis.

Both paracetamol and NSAIDs have a role in oral analgesia for osteoarthritis symptoms. However, while they may be considered for pain relief, they are not an inevitable component of the management of osteoarthritis. Consider potential harms, as well as potential benefits, when deciding whether to initiate them. When paracetamol or an NSAID is used, it should be initiated on a trial basis.

Oral NSAIDs are preferred to paracetamol for the treatment of osteoarthritis, regardless of anatomical location. However, because they also have a greater potential for harm compared to paracetamol, particularly in older people, and people with risk factors for gastrointestinal, kidney or cardiovascular toxicity, their use should be limited to patients at low risk of harms from NSAID use. If an NSAID is used, prescribe the lowest effective dose for the shortest time possible. For further advice on NSAID choice in people at risk of adverse effects, see Choosing an NSAID.

For patients not at low risk of harms from NSAID use, paracetamol or a topical preparation should be considered first line instead.

The evidence for paracetamol in osteoarthritis indicates that on average paracetamol has only a small beneficial effect. However, it has a more favourable safety profile compared to other oral analgesics. Therefore, a trial of paracetamol remains appropriate for any patient requiring oral analgesia for osteoarthritis symptoms, who cannot use an NSAID.

When evaluating the efficacy of an oral NSAID or paracetamol for osteoarthritis symptoms, ensure that the duration of the trial has been adequate and assess treatment response against the goals of management. Goals related to physical function should be the focus; explain to the patient that the aim is to reduce, rather than abolish, pain so that physical function can be maintained.

Stop paracetamol or an NSAID if there is no benefit, symptoms have subsided, or treatment is harmful. If response to the initial NSAID was inadequate, trial switching to a different NSAID before stopping treatment.

Because of the fluctuating nature of osteoarthritis symptoms, it may be necessary to restart an oral NSAID or paracetamol if symptoms recur.

For patients with symptoms evoked by exercise or other physical activity, consider a trial of ‘as necessary’ paracetamol or oral NSAID.

All of the nonsteroidal anti-inflammatory drugs (NSAIDs) listed below are equally effective and drug choice should be based on patient factors (eg comorbidities); see Choosing an NSAID for advice on drug choice. If an NSAID is indicated for pain associated with osteoarthritis, use:

If paracetamol is indicated for pain associated with osteoarthritis, use:

For patients with symptoms that persist throughout the day, consider a trial of modified-release or regular dosing paracetamol, rather than ‘as necessary’ dosing.

There is anecdotal evidence that liver toxicity can occur when therapeutic doses of paracetamol (4 g per day) are used in adults with intrahepatic glutathione depletion. Intrahepatic glutathione depletion can occur in people who are malnourished, cachectic or frail, or have alcoholism or decompensated cirrhosis¹. Liver toxicity is more likely when more than one of these conditions is present. Consider if a lower paracetamol dose is appropriate in these patients.