In November 2015, Cochrane researchers published an overview of non-prescription oral analgesics for acute pain.⁴ This incorporated the findings from 39 Cochrane reviews covering 21 different analgesic drugs, doses and formulations (not all of which are available OTC in the UK).

The study looked at where pain relief was reported as being at least 50 per cent over four to six hours, when compared to placebo. The researchers calculated the number needed to treat (NNT) and the success rates for achieving this level of pain relief.

Products containing ibuprofen in combination with paracetamol came out top, while paracetamol or aspirin on their own were deemed least effective (note there was no information on low-dose codeine combination preparations).⁴

In terms of safety when used for acute pain, the review concluded that “the proportion of participants experiencing an adverse event were generally not different from placebo, except for aspirin 1,000mg and (barely) ibuprofen 200mg plus caffeine 100mg. For ibuprofen plus paracetamol, adverse event rates were lower than with placebo.”⁴

OTC medicines effectiveness

^{[From: RA Moore et al. ‘Non-prescription (OTC) oral analgesics for acute pain’. Cochrane Database of Systematic Reviews. November 4, 2015]}