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Many analgesics are taken by the public with little or no input by healthcare professionals. But research showing high levels of consumer confusion regarding their usage suggests more needs to be done to help them

BY BEING AVAILABLE through so many different outlets, some analgesics have become commodity items – which means the risks associated with them are often overlooked by users.

Research suggests that many consumers are confused about the benefits and risks associated with different types of analgesia, while others remain dissatisfied with their current pain relief medication. It is therefore important to ensure that analgesics are used effectively and appropriately to deliver maximum pain relief with minimal side-effects. This feature will explore some of the key issues around analgesia to ensure pharmacy teams are well equipped to offer good pain management advice.

Q: What is the best way to manage sprains, strains and similar injuries?

A: Sprains and strains are common painful injuries – a sprain is an injury to a ligament resulting from abnormal or excessive forces applied to the joint, whereas a strain or ‘pull’ describes a stretching or tearing of the muscle fibres. Most sprains and strains are minor and can be effectively self-managed using the PRICE principles of treatment, with concomitant OTC analgesia to relieve the associated pain. PRICE involves the following key steps:

• Protect – shield the injured area from further damage (e.g. by using a support of some kind)

• Rest – avoid activity for the first 48-72 hours after injury

• Ice – apply ice wrapped in a damp towel for 15-20 minutes every two to three hours for the first 48-72 hours after injury. Icing reduces blood flow to the damaged ligament or muscle to limit pain and inflammation

• Compression – compress with an elastic or tubular bandage to limit swelling and movement; the fit should be snug but not tight

• Elevation – keep the injured area elevated and supported on a pillow until the swelling is controlled.

Customers should also be advised to avoid HARM (Heat, Alcohol, Running or Massage) for the first 72 hours after injury.

Paracetamol or a topical NSAID is recommended first-line, with codeine added alongside the paracetamol if required. Oral NSAIDs should be avoided in the first 48 hours after injury as their anti-inflammatory effects can hamper the early healing process, but can be recommended for pain relief thereafter.

Q: How can I help those customers affected by backache and arthritic pain?

A: Back pain affects most people at some point in their lives and usually, but not always, resolves spontaneously within 12 weeks. Most low back pain is classed as non-specific (i.e. no underlying cause has been identified), with patients complaining of pain, muscle tension or stiffness. Management centres around pain relief and maintaining mobility.

For acute low back pain (less than six weeks’ duration), paracetamol should be offered first-line, moving onto an NSAID or coxib analgesic if pain relief with paracetamol proves insufficient. If stronger pain relief is required, combining paracetamol with an NSAID/coxib, or adding in an opioid analgesic like codeine, is an option. Hot or cold compression packs can be recommended to provide additional pain relief alongside oral analgesia.

If patients are experiencing muscle spasms as well as pain, a muscle relaxant such as diazepam may be prescribed. In order to manage backache optimally, key lifestyle advice should also be given e.g. keeping active to speed recovery; relaxation and positive thinking; change of sleep position to ease strain on the back; exercise; weight loss; improvements to posture; and stress reduction – all of which can help reduce the risk of future episodes of back pain.

Chronic back pain (longer than six weeks) may require GP intervention to check for potential red flag symptoms. Pain relief options are the same as for acute backache but stronger opioids and a trial of tricyclic antidepressants can also be considered, in addition to physical therapy and exercise.

There are two main forms of arthritis – osteoarthritis (OA), the commonest cause of arthritic pain in the UK, and inflammatory arthritis. OA pain is largely ‘mechanical’ in nature and can be difficult to treat, while inflammatory arthritis and associated joint stiffness tend to respond well to anti-inflammatory analgesics.

OA can target any joint in the body, but the knees, hips and small joints of the hand are most often affected. Regular exercise is central to the management of OA because keeping active and mobile builds muscle mass and strengthens joints, helping to reduce pain. Losing weight is also beneficial as it eases strain on the joints. Regular (rather than ‘as required’) dosing of paracetamol is recommended as a first-line pain management option for OA, with topical NSAIDs additionally recommended for knee or hand OA (to substitute or supplement paracetamol).

Many consumers are confused about the benefits and risks associated with different types of pain relief treatment

Q: When should topical pain relief be recommended?

A: Topicals are particularly popular with patients for managing musculoskeletal pain. Topical NSAIDs are formulated for direct application to the painful site to produce a local analgesic effect while avoiding body-wide distribution of physiologically active levels of drug. As a result, the risk of systemic effects is lower, making topicals a good option for older patients, those at risk of NSAID adverse events and anyone who prefers not to take painkillers orally. However they are not likely to be effective for deep visceral pain or headaches and are not appropriate for use on broken skin or wounds.

Topical NSAIDs are currently recommended first-line for osteoarthritic joint pain by both NICE and the European League Against Rheumatism, and are also endorsed in guidelines as a first choice analgesic for sprains and sprains. When it comes to individual product choice, a recent Cochrane review concluded that all OTC topical NSAIDs are as effective as each other in relieving musculoskeletal pain.

Topical heat therapy (e.g. OTC patches or wraps) can also be beneficial for musculoskeletal pain management – relaxing muscles and improving blood flow to aid recovery and interfering with pain signalling to bring rapid relief. However topical rubefacients are not currently recommended for either acute or chronic musculoskeletal pain as there is too little evidence to support their efficacy.

Q: How do I advise on the right product and dosage for children?

A: Pain in childhood is often overlooked but, with research indicating that around 80 per cent of children and adolescents may have experienced recent pain, effective analgesia is as important as for adults. NICE recommends either paracetamol or ibuprofen as suitable first-line choices for treating mild to moderate pain in children. If the pain persists, the first step should be to check for compliance and ensure parents are giving an appropriate dose. If pain relief is still inadequate, switching from paracetamol to ibuprofen (or vice versa) can be suggested.

If switching has been tried and the child does not respond sufficiently to appropriate doses of one drug alone, parents can try alternating paracetamol and ibuprofen – for example, adding a dose of the second drug after two to three hours. However, because paracetamol is usually given every six hours and ibuprofen every eight hours, care needs to be taken not to exceed the maximum dose of each drug in a 24-hour period. NICE guidance says to only consider alternating these agents if a child’s distress from, say, feverish illness persists or recurs before the next dose is due.

For OTC infant analgesic suspensions, it is important to consult the age-appropriate dosing advice on each specific product and advise parents to use the supplied dosing syringes or spoons to ensure the greatest accuracy. You could also suggest using a treatment diary to record which was the last drug given and at what time. Simultaneous administration of paracetamol and ibuprofen is not recommended for pain management in children.

Repeated consumption of any opioid analgesic carries the risk of developing psychological and physical dependence

Q: What does the pharmacy team need to know about medication overuse headache?

A: Medication overuse headache (MOH) is a chronic daily headache caused by over-consumption of analgesics to treat an existing headache disorder. MOH affects around one in 50 adults in the UK. As part of their overall pain management role, the pharmacy team should be vigilant for customers at risk of developing MOH: those regularly taking simple OTC pain relievers on 15 or more days per month or codeine-containing analgesics on 10 or more days per month.

According to the British Association for the Study of Headache (BASH)8, prevention of MOH is preferable to management, so patients presenting in pharmacy with primary headaches should be advised about the risks and educated on appropriate analgesic use (particularly dose and duration). It is also important to be aware that certain OTC pain relievers – particularly those containing codeine and/or caffeine – can increase the risk of MOH.

Once MOH is established, the only effective treatment is to withdraw the suspected causative medication(s) to avoid everworsening headaches. The withdrawal process typically requires specialist intervention as symptoms will initially be aggravated and relapse is common. Withdrawal headaches can be managed with naproxen 250mg or 500mg daily.

Q: What about the risk of opioid dependence?

A: Codeine and dihydrocodeine are weak opioid analgesics that can be useful for the relief of mild to moderate pain, particularly visceral pain. However side-effects (notably nausea and constipation), coupled with the potential risk of dependence, make them unsuitable for long-term use. Although rarely a problem with therapeutic dosing for pain, it is important to be aware that repeated consumption of any opioid analgesic carries the risk of developing psychological and physical dependence. Consequently, caution is advised when recommending opioidcontaining analgesics to any customer with a history of drug or alcohol dependence.

Other patients at higher risk of developing opioid dependence include those with a family member with a history of substance abuse, poor social support and co-morbid psychiatric disorders. The capacity to metabolise codeine to morphine also varies considerably between individuals, leading to a marked increase in morphine toxicity in ultra-rapid codeine metabolisers and a reduced therapeutic effect in poor codeine metabolisers.

Q: How do I mitigate and manage the risk of side-effects with analgesics?

A: Appropriate recommendation of OTC analgesics, ensuring they are safe and suitable for each individual customer, is key to reducing the risk of side-effects. Paracetamol is generally welltolerated when used at the recommended daily dose to relieve pain and, in older patients and those with risk factors for GI adverse events, it is likely to be a safer option than NSAIDs. However it should be avoided in those with hepatic impairment or alcohol dependence due to an increased risk of liver damage.

The commonest side-effects of NSAIDs are dyspepsia and other upper GI complications; CV and renal adverse events are serious but rare. NSAIDs may also exacerbate or precipitate asthma. Customers are at high risk of GI side-effects if they are 65 years or older; use high doses of NSAIDs; have a history of GI ulcer, bleeding or perforation; use concomitant medications that increase GI effects (e.g. anticoagulants or aspirin [even at low doses]); or have another serious co-morbidity such as diabetes or hypertension. When recommending an NSAID it is important to consider carefully the risk/benefit balance, especially in older people, and those with asthma, chronic kidney disease or heart conditions.

Q: What about the risk of analgesic overdose?

A: As with all medicines, selecting the right dose and duration of use is key to keeping the benefits of analgesics favourably balanced against their potential risks. To minimise side-effects, it is recommended that NSAIDs are used at the lowest effective dose needed to control pain for the shortest duration of time possible. The recommended OTC dose of ibuprofen is 200-400mg three times daily. Overdosage with ibuprofen may cause nausea, vomiting, epigastric pain and tinnitus, but more serious toxicity is very uncommon.

With paracetamol, the potential risk of accidental overdose is exacerbated by the vast array of OTC products that contain paracetamol as an ingredient – particularly combination analgesics targeting different types of pain, and cold and flu remedies.

In OTC pain management, the recommended dose of PAIN MANAGEMENT PHARMACY MAGAZINE NOVEMBER 2014 35 paracetamol is 500-1,000mg, with no more than four doses in each 24-hour period. Even in the absence of significant early symptoms, any patient with a suspected paracetamol overdose requires urgent medical attention as liver damage becomes maximal three to four days after overdose. Hepatotoxicity may occur after a single ingestion of more than 150mg/kg paracetamol taken in less than one hour.

Rarely, liver damage may also develop with single ingestions as low as 75mg/kg of paracetamol in less than one hour.

Q: When should diclofenac be recommended or avoided?

A: Diclofenac has similar analgesic efficacy to naproxen and, like all NSAIDs, can be used for the relief of mild to moderate pain and inflammation. It is specifically indicated for the relief of rheumatic or musculoskeletal pain and postoperative pain and, along with ibuprofen, is also commonly used in dental pain. However, diclofenac also carries specific risks that set it apart from other NSAIDs and preclude its use in specific groups of customers.

Like the selective COX-2 inhibitors, diclofenac is contraindicated in ischaemic heart disease, cerebrovascular disease, peripheral arterial disease and mild to severe heart failure5. It should be used with caution in patients with a history of cardiac failure, left ventricular dysfunction, hypertension, oedema and any patient with risk factors for CV events5. Ibuprofen (up to 1,200mg per day) or naproxen (up to 1,000mg per day) are preferred over diclofenac as first-line NSAID options in those customers at risk of CV events.

The CHM has also designated diclofenac as ‘intermediate risk’ for NSAID-induced GI adverse events. Naproxen is also intermediate risk, while ibuprofen carries the lowest risk.

Balancing the risks and benefits of aspirin

Deeper understanding of aspirin’s properties – particularly its antiplatelet effects – has led to ever-increasing therapeutic claims for this once humble analgesic. Aspirin is now recommended for the prevention and treatment of various aspects of CV disease in leading UK and European management guidelines.

In the UK, long-term use of aspirin (75mg/day) is recommended for secondary prevention in established CV disease, and also has a role in the management of atrial fibrillation, intermittent claudication, stable angina, acute coronary syndromes and following coronary bypass surgery.

Much debate has surrounded the health benefits of daily aspirin therapy but evidence is emerging to suggest that regular use may reduce the risk of cancer, particularly ovarian, colon, bowel, stomach and oesophageal cancer. Other studies have linked daily aspirin use to a reduced risk of pregnancy complications in women with pre-eclampsia and a reduced risk of dementia. However, in other trials, aspirin has been found to cause more harm than good, raising the risk of GI bleeding and even increasing the likelihood of developing age-related macular degeneration.

To answer these questions more definitively, a recent large-scale systematic review explored prophylactic aspirin use in the general population. This new study found that, taken for a minimum of five years at doses of 75-325mg/day, the overall benefit-harm profile of aspirin was favourable. This means that, for average-risk individuals aged 50-65 years taking aspirin for 10 years, there would be a relative reduction of between 7 per cent (women) and 9 per cent (men) in the number of cancer, myocardial infarction or stroke events over a 15-year period, and an overall 4 per cent relative reduction in all deaths over a 20-year period.

Excess bleeding was found to be the most important harm associated with aspirin use in this study and its risk and fatality rate increased with age.

For now, the evidence is not robust enough for aspirin to be recommended in the UK for either the primary prevention of CV disease or cancer risk reduction. Aspirin also carries important contraindications and cautions that must always be borne in mind to ensure the optimal risk/benefit balance is maintained. This includes concomitant PPI use in those on long-term aspirin therapy at risk of GI bleeding.