Pain, General | September 8, 2015 | Author: The Super Pharmacist
Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used to reduce inflammation (redness and swelling), relieve pain, and bring down a temperature. The first NSAID, aspirin (acetylsalicylic acid), was developed in 1897.
NSAIDs are commonly used in the treatment of headaches, toothache, painful periods, the common cold, and soft tissue injuries such as sprains and strains. They are available in a number of different forms including tablets and capsules, eye drops and injections, and topical treatments such as creams, gels or lotions that are rubbed into specific parts of the body. Topical anti-inflammatories contain an anti-inflammatory medicine such as ibuprofen, diclofenac, ketoprofen, felbinac and piroxicam.
Orally administered anti-inflammatory medication work by inhibiting the effect on enzymes called cyclo-oxygenase (COX) enzymes. COX enzymes produce chemicals known as prostaglandins, some of which are involved in the production of pain sensations at sites of injury or damage. Therefore, a reduction in prostaglandin subsequently reduces pain and inflammation.
Topical creams, gels and lotions work in the same way but the action is only experienced where they have been applied and absorbed through the skin. From here, they then move into areas of the body where there is inflammation (such as a muscle).
The topical method of administration often results in a much smaller total of anti-inflammatory medicine in the body when compared to the use of tablets or capsules, which also means using topical products results in less side effects related to dose.
A number of systematic reviews have been undertaken to ascertain the safety and effectiveness of NSAID use. The majority of studies compare the concentration of topical NSAIDS in plasma and synovial fluid as an indicator of their effectiveness and potency, with a large majority focused on the use of topical applications in the treatment of sprains and musculoskeletal injuries.
In general, the clinical indication of most NSAIDs is that they:
1. Result in peak plasma concentrations that are significantly lower than orally administered drugs of the same dosage and medicine, and
2. Topically administered drugs have less long term side effects than systemic drug administration.
There are a number of studies that focus on the plasma concentration of topical treatments of ibuprofen, with levels typically below 500ng/mL. These concentrations are significantly lower than peak concentrations of orally administered ibuprofen at a standard dose of 400mg, which are typically above 20,000ng/mL (1,2,3).
Ketoprofen administered orally also has significantly higher concentration levels than its topical counterpart (2600ng/mL compared to 20ng/mL), as does diclofenac (4).
The significant differences in plasma concentration levels highlight some of the concerns around the widespread use of oral NSAIDs and the associated systemic exposure to all parts of the body. This is a particular concern given the wide range of individuals who have to pay close attention to levels of NSAID administration due to its known detrimental impact on health – orally administered medicines are associated with a small increased risk of heart attack, stroke, and heart failure (5).
High risk groups include:
The comparative literature reviewing the efficacy of different NSAID administration is limited, largely due to some of the methodological difficulties of comparing two separate routes of administration and an over reliance on qualitative data that is open to significant bias.
A systematic review of seven studies making a direct comparison of topical and oral NSAIDs, specifically for the treatment of chronic injuries such as osteoarthritis of the knee, found them both to demonstrate similar efficacy for treatment of both acute and chronic pain in musculoskeletal injuries and sprains (7).
The major identified benefits of using topical cream in this instance are the localised nature of its application and the reduced likelihood of systemic exposure and subsequent health risk.
The same study, in comparison with a significant number of other NSAID studies, also highlighted the significantly increased risk of gastrointestinal side effects associated with oral administration.
Topical applications have been evidenced to be associated with far less side effects and complications
Given that many topical creams, ointments and gels present significantly less side effects than orally administered drugs, they are particularly popular in high risk groups such as the elderly. Studies of older populations reveal that topically administered NSAIDs can achieve similar pain relief to oral drugs whilst requiring only a fraction of the total systemic daily dose, the avoidance of first-pass metabolism, major drug interactions, and less risk of subsequent infection (8). This is one of the main reasons why prescribing patterns, or medical advice, generally favour topical administration in patients > 75yrs and those with pre-existing gastrointestinal risk.
The evidence is clear that in regards to both safety and tolerability, topical NSAIDs often present significantly better options to patients than oral NSAIDs (particularly when administered on a longer term basis) for localised inflammatory conditions. As such, individuals with general sprains, strains and musculoskeletal injuries should consider topical NSAIDs on the basis of their safety profile, lack of systemic exposure, and equal efficacy to oral drugs. Similarly, patients with underlying health conditions who can topically apply NSAIDs rather than take tablets should be encouraged to do so in order to reduce the risk of long term adverse side effects associated with anti-inflammatory use.
1. Cagnie et al (2003) Topical NSAIDs: plasma and tissue concentrations Phys Ther 83(6):707-12
2. Osterwalder A, Reiner V, Reiner G, Lualdi P (2002) Tissue absorption and distribution of ketoprofen after patch application in subjects undergoing knee arthroscopy or endoscopic carpal ligament release Arzneimittelforschung 52:822–827
3. Cevc G, Mazgareanu S, Rother M (2008) Preclinical characterization of NSAIDs in ultradeformable carriers of conventional topical gels Int J Pharm 360(1-2):29-39
4. C Rolf et al (1999) Intra-articular absorption and distribution of ketoprofen after topical plaster application and oral intake in 100 patients undergoing knee arthroscopy Rheumatology 38: 564-567
5. Bavry AA, Thomas F, Allison M, Johnson KC et al (2014) Nonsteroidal anti-inflammatory drugs and cardiovascular outcomes in women: results from the women’s health initiative Circ Cardio Qual Out 7(4):603-10
6. Tiso RL, Tong-Ngork S, Fredlund KL (2010) Oral versus topical ibuprofen for chronic knee plan: a prospective randomised control study Pain Physician 13(5):457-67
7. Klinge SA, Sawyer GA (2013) Effectiveness and safety of topical versus oral nonsteroidal anti-inflammatory drugs: a comprehensive review Phys Sportsmed 41(2):64-74
8. Stanos SP, Galluzzi KE (2013) Topical therapies in the management of chronic pain Postgrad Med 125(4 Suppl 1):25-33
9. Altman RD, Barthel L (2011) Topical therapies for osteoarthritis Drugs 71(10):1259-79