Retail prices for some of the most popular branded prescription medicines in the US leapt 8.3% on average in 2009, far outstripping inflation, according to insurance group AARP’s Rx Price Watch Report.

Moreover, this average annual increase was notably higher than the rates of retail price growth during the prior five years, which ranged between 6% and 7.9% during the years 2005 to 2008, the group said.

The analysis found that 211 of 217 brand-name prescription drugs had retail price boosts overshooting general inflation last year (-0.3%), with Boehringer Ingelheim's prostate drug Flomax (tamsulosin) top of the list with a 24.8% hike in cost.

According to report co-author Stephen Schondelmeyer, professor of pharmaceutical economics at the University of Minnesota, the results “confirm yet again that drug manufacturers are raising prices far beyond what normal inflation is”.

Substantial increases in the retail prices of many commonly-used medicines were also seen over the five-year period: Flomax rocketed 92%; GlaxoSmithKline's asthma drug Advair (salmeterol/fluticasone propionate) and Eisai's dementia drug Aricept (donepezil) each swelled around 40%; and AstraZeneca's anti-heartburn Nexium (esomeprazole) jumped 28%, all representing growth well over and above that seen in other consumer goods and services.

John Rother, AARP executive vice president of policy and strategy, reportedly called on both Congress and the pharmaceutical industry to boost competition and transparency in the market, warning: “Unless something is done to bring down their skyrocketing price increases, lifesaving medicines will be out of reach for too many”.

However, in defence of the industry, The Pharmaceutical Research and Manufacturers of America said the report is misleading, “because nearly half of the drugs on its top 25 brand-name drug list were filled as generics in the first part of 2010, but AARP counts these drugs as if they were brand-name drugs”.

“The result is an overstatement of consumers’ actual costs for these medicines and there is a tremendous disparity between AARP’s report and the numerous independent analyses showing drug costs growing slowly”, it stressed.