Download OTC pain management guidelines - South African Pharmacist`s

OTC pain management guidelines
Catherine Whittaker (B.Pharm)
Abstract
Globally there is an ever increasing demand from patients for access to effective nonprescription medicine. As a result, the range of over-the-counter (OTC) products, including
analgesics, is expanding. A wide variety of OTC analgesics are available to patients
enabling them to effectively self manage many painful conditions. However, the
inappropriate use of analgesics can pose a significant health risk. We need to educate our
patients regarding the appropriate selection and use of these products. Pain management
guidelines are a useful resource to assist us with analgesic selection. This article provides
an overview of current pain management guidelines, reviews the safety and efficacy of OTC
analgesics and some recommendations for patient counselling on the use of analgesics.
Introduction
Over-the-counter analgesics are used by millions of people daily to treat acute, painful
conditions. The choice of a suitable OTC analgesic can be overwhelming for patients as
there are numerous brands, combinations and formulations available.
The current pain management guidelines are a valuable tool that can guide us when
providing recommendations regarding analgesia. Other factors that need to be considered
when selecting an analgesic are the cause, severity and nature of the pain, the
characteristics of the drug and the individual patient. Finally, we need to educate patients
regarding the safe use of a product and also provide information when a product may be
unsuitable given the fact that analgesics are kept at home for future use and may be
recommended to others.
Understanding pain: The International Association for the Study of Pain defines pain as “an
unpleasant sensation or emotional experience with actual or potential tissue injury”.1
Pain is always subjective, and is affected by the persons’ mood, morale and the meaning of
pain for that patient.1 People differ remarkably in their ability to tolerate pain and therefore
patients with similar conditions report different pain intensities2.
Classification of pain: Health care professionals generally classify pain as:



mild
moderate
severe
Visual charts or pain scales are sometimes used to measure and monitor pain. In preverbal
children, facial expression is the most valid indicator of pain.1
Assessment of pain: The first step in pain management should be to take a comprehensive
patient history so as to identify the underlying cause of pain and eliminate this where
possible. If the underlying cause of pain is unknown, the patient should be referred to their
doctor.
The most reliable description of pain is from the patient and thorough questioning should be
used to understand the severity, nature and history of the pain (See table 1).
Table 1: Pain assessment criteria1
 Duration
 Severity
 Site
 Character or type of pain e.g. stabbing, throbbing
 Persistent or intermittent
 Distribution of pain
 Relieving or aggravating factors
 Accompanying symptoms, including vital signs (heart rate, temperature, blood
pressure)
 Referred pain
Generally, in the pharmacy, patients seek our assistance for the management of mild to
moderate acute pain. Acute pain is usually self-limiting. Chronic pain is pain that lasts for
weeks, months and even years and such patients, particularly those that use analgesics
continually, should be referred to their doctor2.
Medical conditions that are suitable for management with an OTC analgesic include
headache, toothache, dysmenorrhoea, minor musculoskeletal injuries or the pain associated
with other medical problems such as sinusitis, colds or influenza. OTC analgesics are
usually effective for these conditions3.
Management of pain:
Pain management guidelines: There are numerous guidelines regarding acute pain
management and these provide a framework to assist in the selection of a safe and effective
analgesic.
The “analgesic ladder” forms the basis of many approaches to the use of analgesics (see
table 2).4 Non-opioids (e.g. aspirin, paracetamol or ibuprofen) are the drugs of choice for the
management of mild pain. However, the analgesic efficacy of non-opioids is limited by side
effects and a ceiling effect, as beyond a certain dose no further pharmacological effect is
seen.4 More potent analgesics may be required if the pain does not respond to non-opioids.4
Strong opioids such as morphine are the most potent analgesics and because they are so
effective they are the mainstay for treating severe pain.2
Table 2: Analgesic Ladder
1. Mild pain
Non-opioids e.g. aspirin, paracetamol,
ibuprofen, naproxen
2. Moderate pain
Weak opioids such as codeine with one of
the analgesics used for mild pain
3. Severe pain
Strong opioids used alone or together with
non-opioids listed for mild pain
In 2008, the Department of Health published the Primary Health Care Standard Treatment
Guidelines and Essential Drug List of South Africa which covers the management of acute
pain (see table 3)1. These guidelines also recommend the use of non-opioid treatment
(NSAID or paracetamol) for the management of acute mild pain.
Table 3: South African acute pain control
guidelines (mild-moderate pain)1
Acute mild pain
1. Children
2. Adults with non-inflammatory or
post trauma pain
3. Adults with pain associated with
trauma or inflammation
Acute moderate pain
1. Children
2. Adults
Manage with oral paracetamol,
15mg/kg/dose 4-6 hourly when required with
a maximum of 4 doses in 24 hours
Manage with paracetamol, with a maximum
of 4 doses per 24 hours
Manage with ibuprofen given orally 400mg 68 hourly with food, up to 1200mg per day
unless prescribed by a doctor
If no relief is obtained after two or three
doses, combine paracetamol and ibuprofen
at the above dosages
Children who do not respond to paracetamol
should be referred to a doctor
Adults who do not respond to the therapy
above should be referred
Tramadol 50mg 4-6 hourly may be
prescribed
OTC analgesics: Despite an enormous range of OTC products marketed for a wide range
of painful conditions, there are actually a limited number of active ingredients available,
including: paracetamol, aspirin, and non-steroidal anti-inflammatories such as ibuprofen.
These drugs are often combined with each other or with other agents such as codeine,
doxylamine and caffeine to produce a more effective analgesic.3
An extensive range of dosage forms are available including syrups, suspensions,
suppositories, powders, tablets, capsules, chewable tablets, soluble tablets etc. Soluble
agents or liquids may have the advantage of a faster onset of action.
Following consideration of the pain management guidelines, an analgesic should be
selected based on a thorough medical history, considering coexisting medical conditions and
any concurrent medication that the patient is taking, which may interact with the analgesic
treatment.
Paracetamol is the most widely used antipyretic and analgesic agent and is the drug of
choice for the management of mild to moderate pain.1. The exact mechanism of action for
paracetamol remains unclear despite extensive research.3
Its analgesic and antipyretic effects are as effective as aspirin and other NSAIDs but it has
little or no anti-inflammatory action.5 It is effective, well tolerated and safer than NSAIDs as it
has no effect on platelets and no cardiac or gastrointestinal adverse events.3, 5
Paracetamol has few drug interactions of any significance.5,7 However, it is important to
obtain information regarding the patients’ concomitant medication so as to avoid concurrent
use with other paracetamol-containing products as this may inadvertently lead to a
paracetamol overdose.
Paracetamol is largely metabolised by the liver and can cause liver toxicity at high doses3,7.
The dose of paracetamol should be reduced in elderly patients with reduced hepatic function
or in patients with a history of alcohol abuse due to an increased risk of toxicity.3 All
overdoses of paracetamol should be taken seriously and patients or parents should be
referred immediately to their nearest hospital.
Aspirin: is antipyretic, analgesic and anti-inflammatory. Aspirin is also used in low doses,
chronically, as an anti-thrombotic agent for cardiovascular protection. Aspirin is the oldest
and best-known NSAID and is still widely used in pain management despite safer
alternatives being available. Its mechanism of action is due to the inhibition of prostaglandin
synthesis, which is partially responsible for the sensation of pain.2, 4, 7
Aspirin has anti-inflammatory activity only at higher doses (greater than 4g daily) and
therefore other NSAIDs are preferred for inflammation as they are better tolerated.3
Aspirin and NSAIDs, due to both local irritation of the stomach and systemic inhibition of
protective prostaglandins found in the stomach, can cause mild gastrointestinal adverse
events such as abdominal pain and dyspepsia as well as severe events such as peptic
ulcers and gastrointestinal bleeding.4 Measures such as enteric coating or taking the aspirin
after food may reduce the risk of gastric irritation but does not eliminate this risk. 2 Aspirin has
an effect on platelets that reduces clotting and this increases the risk of bleeding.2,3
Aspirin and NSAIDs are associated with numerous cautions and contraindications in a
number of patient groups, even at OTC doses that need to be considered prior to
recommending them (table 4)5. Aspirin and NSAIDs should be used with caution in elderly
patients due to the high incidence of cardiovascular disease, gastrointestinal disease, agerelated decline in renal function and multiple medication use in this population group.3,7
Table 4: Cautions and contraindications with NSAIDS5
 Use in the elderly
 History of or existing GI ulceration, perforation or bleeding due to an increased
risk of a GI bleed
 History of bronchospasm, asthma or rhinitis associated with aspirin or other
NSAIDs
 Severe hepatic or renal disease
 Existing cardiovascular disease due to an increased risk of a cardiovascular
event
 Pregnancy
 Use of other NSAIDs
 Concurrent anticoagulant or steroid therapy
 Breast feeding*
 Under 16 years of age*
 Gout*
*aspirin only
Other NSAIDS:
Ibuprofen and naproxen: are available as OTC products and like aspirin are antipyretic,
analgesic and anti-inflammatory. These NSAIDs, due to their anti-inflammatory activity, are
the drugs of choice in the management of pain associated with inflammation or trauma. The
ibuprofen dose required for anti-inflammatory activity is 300-600mg, with a maximum OTC
dose of 1200mg daily.
Ibuprofen, naproxen and other NSAIDs are considered therapeutically equivalent, although a
particular individual may respond better to one agent than another.2, 7 NSAIDS vary in how
quickly they work and how long they relieve pain.2 Ibuprofen and naproxen are better
tolerated than aspirin as they cause less gastrointestinal irritation. Although, in general, the
NSAIDs share similar adverse reactions.7
The lowest effective dose of NSAIDs should be used for the shortest possible duration to
reduce the risk of serious adverse effects.7
Topical NSAIDs should be considered for the management of musculoskeletal conditions
such as strain, sprains and sciatica. The use of topical preparations reduces the risk of
adverse events associated with NSAID use.
Codeine: is a weak opioid analgesic which is structurally similar to morphine. A dose of at
least 15mg is required for analgesic effect.3, 4 Codeine in OTC products is only found in
combination products with aspirin, paracetamol or ibuprofen and is used for the
management of moderate pain. Constipation is a common adverse effect and elderly
patients are particularly susceptible to this adverse event. Codeine may also cause
drowsiness and has the potential for physical and psychological abuse.
Caffeine: is included in some analgesic preparations and may have a synergistic effect with
analgesics.3,6 A dose of at least 100mg is required to produce such effects, this dose is
similar to the caffeine present in a cup of tea. Products containing caffeine are best avoided
near bedtime because of their stimulant effect. Caffeine has an irritant effect on the stomach
and has the potential for psychological and physical dependence.3, 5
Doxylamine: is an antihistamine whose sedative and relaxing effects are probably
responsible for its usefulness in treating tension headaches.3 It can cause drowsiness.
Analgesics in special populations
Children: Paracetamol is the drug of choice for the management of pain for children under
the age of 12 years and can be given to babies from 3 months of age.1, 7 A wide range of
paediatric formulations are available including suppositories, suspensions and sugar free
solutions.
Ibuprofen suspension is available OTC and can be administered to babies from three
months of age.7
Aspirin should not be given to children under twelve years of age (some experts
recommend 16 years of age) due to the suspected link with Reye’s syndrome.3
Pregnancy: Paracetamol is the drug of choice for the management of pain in pregnancy
and is also safe to use during breastfeeding.3, 7
Counselling: Patients should be counselled regarding the recommended dose, dosing
regimen and recourse if the analgesic is ineffective (See table 4).
Table 4: Recommended advice with OTC analgesics6
 Do not exceed the daily recommended dose
 Avoid excessive alcohol intake
 Do not give aspirin to children
 Consult a doctor if symptoms last longer than 3 days
 Take with a full glass of water and preferably after food (aspirin and NSAIDs)
 Inappropriate regular use of codeine or dihydrocodeine can lead to physical
and psychological dependence
 Constipation can occur frequently with codeine
 Medication overuse headaches can occur if analgesics are used
inappropriately
Conclusion: Patients in the pharmacy frequently seek our advice and recommendations
regarding the management of pain. The acute pain management guidelines should be
considered when recommending analgesics. It is also our responsibility to obtain the
information needed to personalise the selection of an analgesic thus ensuring safe and
effective analgesia.
References:
1. Standard Treatment Guidelines and Essential Drug List of South Africa, Primary
Health Care, Department of Health 2008
www.doh.gov.za/docs/factsheets/index.html
2. The Merck Mannual of Medical Information, Home Edition 1997
3. Blenkinsopp A, Paxton P. Symptoms in the Pharmacy - A guide to the
management of common illness. 3rd Ed. Blackwell Science.2000.
4. Walker R and Edwards C Clinical Pharmacology and Therapeutics 3rd Edition
5. Dickman A, Choosing over the counter analgesics, The Pharmaceutical Journal
2008;281:631
6. Dickman A, Personalising OTC analgesia, The Pharmaceutical Journal
2008;281:701