3 Adverse effects

Ibuprofen appears to have the lowest incidence of gastrointestinal adverse drug reactions (ADRs) of all the non-selective NSAIDs. However, this only holds true at lower doses of ibuprofen, so over-the-counter preparations of ibuprofen are generally labelled to advise a maximum daily dose of 1.2 grams.

Main article: Non-steroidal anti-inflammatory drugNon-steroidal anti-inflammatory drugs usually abbreviated to NSAID s, are drugs with analgesic, antipyretic and anti-inflammatory effects they reduce pain, fever and inflammation. The term "non-steroidal" is used to distinguish these drugs from steroids,

3.1 Reported ADRs

Common adverse effects include: nausea, dyspepsia, gastrointestinal ulceration/bleeding, raised liver enzymes, diarrhoea, headache, dizziness, salt and fluid retention, hypertension (Rossi, 2004)

Infrequent adverse effects include: oesophageal ulceration, heart failure, hyperkalaemia, renal impairment, confusion, bronchospasm, rash (Rossi, 2004)

3.2 Photosensitivity

As with other NSAIDs, ibuprofen has been reported to be a photosensitising agent. (Castell et al., 1987) Ibuprofen, however, has a very weak absorption spectrum which does not reach into the solar spectrum . The molecule contains only a single phenyl moiety, and no bond conjugation, resulting in a very weak chromophore system. Ibuprofen, therefore, is only a very weak photosensitising agent when compared with other members of the 2-arylpropionic acids.

4 Stereochemistry

Ibuprofen, like other 2-arylpropionate derivatives (including ketoprofen, flurbiprofen, naproxen, etc) contains a chiral carbon in the β-position of the propionate moiety. As such there are two possible enantiomers of ibuprofen with the potential for different biological effects and metabolism for each enantiomer.

Indeed it was found that S-ibuprofen ( dexibuprofen ) was the active form both in vitro and in vivo.

Logically then, there was the potential for improving the selectivity and potency of ibuprofen formulations by marketing ibuprofen as a single-enantiomer product (as occurs with naproxen, another NSAID).

Further in vivo testing, however, revealed the existence of an isomerase which converted R-ibuprofen to the active S-enantiomer. Thus, due to the expense and futility that might be involved in marketing the single-enantiomer, all ibuprofen formulations currently marketed are a racemic mixture of both enantiomers.

5 Availability

Ibuprofen was made available under prescription in the United Kingdom in 1969. In the years since, the good tolerability profile along with extensive experience in the community (otherwise known as Phase IV trials), has resulted in the rescheduling of small packs of ibuprofen to allow availability over-the-counter in pharmacies worldwide. Indeed there has been an increasing trend towards descheduling ibuprofen such that it is now available in supermarkets and other general retailers.

6 References

• Rossi S (Ed.) (2004). Australian Medicines Handbook 2004. Adelaide: Australian Medicines Handbook. BooksEnthsiast.com.
• Castell JV, Gomez MJ, Miranda MA, Morera IM (1987). Photolytic degradation of ibuprofen. Toxicity of the isolated photoproducts on fibroblasts and erythrocytes. Photochem Photobiol 46 (6), 991-6.

Analgesics
{ Acetaminophen (Paracetamol)}
#REDIRECT NSAIDs	Opioids { Alfentanil} { Buprenorphine} { Carfentanil } { Codeine} { Dextropropoxyphene} { Dihydrocodeine} { Endorphin} { Fentanyl} { Heroin} { Hydrocodone} { Hydromorphone} { Methadone} { Morphine} { Oxycodone} { Remifentanil } { Sufentanil} { Tramadol}

Non-steroidal anti-inflammatory drugs Over-the-counter substances

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