Medicine cabinet mainstay ibuprofen has been hitting the headlines in recent months due to the discovery that an already-existing formulation of the drug, in use around the world because it increases the solubility of the medication, could reduce the risk of cardiovascular side effects. It’s just one potential new chapter to add to the decades-long story of one of today’s most popular over-the-counter pharmaceuticals.
It all began in the 1950s when a team of Boots scientists started work on finding a treatment for rheumatoid arthritis that could be better tolerated than aspirin, the main painkiller on the market. Although aspirin, which was the first non-steroidal anti-inflammatory drug (NSAID) marketed in 1899, was commonly used at the time, it had to be given in very high doses, making the risk of side effects, such as an allergic reaction, bleeding and indigestion, high.
The man in charge of the mission was Dr Stewart Adams, who, together with chemist Dr John Nicholson and technician Colin Burrows, set out testing the potency of more than 600 chemical compounds in the hope of finding just one that would meet their criteria. It wasn’t until 1961 that they succeeded, filing a patent for the compound 2-(4-isobutylphenyl) propionic acid, later to become known as ibuprofen.
The patent was granted in 1962 and seven years later, ibuprofen was approved as a prescription drug. But this was far from the end of the story for the now-ubiquitous over-the-counter (OTC) drug. During the 1970s, Boots tested the medication for further properties, leading to it being marketed for dental pain, period pain and headaches; by 1983 it had become the first drug to move from prescription to OTC in the UK, with the US quickly following in 1984. By this point, Boots scientists had been taking it for years for headaches and hangovers.
The present day
Fast forward to today and ibuprofen has become a mainstay of most medicine cabinets. People take the NSAID, which reduces inflammation by blocking the enzymes (COX-1 and COX-2) that are needed to make prostaglandins (the chemicals released in response to injury or illness and which cause pain, swelling or fever), for everything from headaches to back pain and muscle soreness.
Don’t want ibuprofen in tablet form? There are plenty of other ways to take the drug, which was sold to British consumer goods company Reckitt Benckiser as part of the company’s acquisition of Boots Healthcare in 2005. Indeed, while Reckitt Benckiser’s Nurofen comes in 11 different forms – from a topical gel to a soft gel cap – ibuprofen is also sold under a number of other brand names across the world, including Advil and Motrin. An incredible 20,000 tonnes of the drug is now made every year.
Yet, while ibuprofen’s popularity shows no signs of waning, not all recent news about the more-than-50-year-old medication has been good. A new study published in the British Medical Journal (BMJ) in September 2016, for example, detailed the risks associated with NSAIDs, focusing on increased risk of heart failure.
The study, which used data for almost 10 million NSAID users from the UK, the Netherlands, Italy and Germany who started treatment between 2000 and 2010, found that people who had taken any NSAID in the previous 14 days had a 19% increased risk of hospital admission for heart failure compared with people who had used NSAIDs at any point in the past.
The higher the dose of the NSAIDs, the higher the risk of heart trouble. And the risk of admission for heart failure increased for seven medications in particular: ibuprofen, naproxen, diclofenac, indomethacin, ketorolac, nimesulide and piroxicam.
A new discovery
The next chapter in ibuprofen’s story could see this issue addressed, as recent research carried out by scientists at Imperial College London has shown that an already-existing formulation of ibuprofen called ibuprofen arginate could allow people to take higher doses – but without the cardiovascular side effects associated with the current formulations found in OTC products. Plus, in addition to being better tolerated, ibuprofen arginate (which isn’t currently licensed in the UK) is also released into the bloodstream more rapidly than the current formulations, likely providing faster pain relief.
Naturally-occurring amino acid arginine, which is sold in many health food stores, had previously been suggested by the same team of scientists to protect susceptible people from the increased risk of cardiovascular side effects caused by taking common COX-2 blocking pain medications. In the current study, they discovered that ibuprofen arginate works just like arginine in the cardiovascular system, which, they think, suggests that this type of ibuprofen may have fewer cardiovascular side effects than other types of similar pain medications.
“The formulation is not new, what is new is the appreciation of the potential for arginine in the formulation to act as an active ingredient to protect the cardiovascular system,” explains Professor Jane Mitchell, PhD, a researcher involved in the work and head of Cardiothoracic Pharmacology, Cardiothoracic Pharmacology and Vascular Biology Section at the National Heart and Lung Institute at the Institute of Cardiovascular Medicine and Science at Imperial College London.
“We’re currently at the proof of concept stage – i.e. [we’ve proven the concept] that the arginine in ibuprofen arginate can act like regular arginine in cells and in blood vessels in vitro and in vivo. The next stage is to perform a clinical trial to study the effects of ibuprofen arginate versus regular ibuprofen on vascular function in people.”
The good news, according to Mitchell, is that the formulation is already available in various countries around the world, because it increases the solubility of ibuprofen. “I think that if we find any evidence that ibuprofen arginate protects vascular responses in people this will be enough to consider repositioning the drug,” she concludes.