The doctors claim that the state wastes money on unnecessary medicine that they blame for up to 20,000 deaths annually

Half of all medicines being prescribed by doctors in France are either useless or potentially dangerous for patients, according to two eminent medical specialists. They blame the powerful pharmaceutical companies for keeping these drugs on sale at huge expense to the health system and the taxpayer.

Professor Philippe Even, director of the prestigious Necker Institute, and Bernard Debré, a doctor and member of parliament, say removing what they describe as superfluous and hazardous drugs from the list of those paid for by the French health service would save up to €10bn (£8bn) a year. It would also prevent up to 20,000 deaths linked to the medication and reduce hospital admissions by up to 100,000, they claim.

In their 900-page book The Guide to the 4,000 Useful, Useless or Dangerous Medicines, Even and Debré examined the effectiveness, risks and cost of pharmaceutical drugs available in France. Among those that they alleged were "completely useless" were statins, widely taken to lower cholesterol. The blacklist of 58 drugs the doctors claimed are dangerous included anti-inflammatories and drugs prescribed for cardiovascular conditions, diabetes, osteoporosis, contraception, muscular cramps and nicotine addiction.

The Professional Federation of Medical Industrialists denounced the doctors' views as full of "confusions and approximations".

"This book is helping to alarm those who are sick needlessly and risks leading them to stop treatments," it saidin a statement.

Christian Lajoux, the federation's president said: "It is dangerous and irresponsible … hundreds of their examples are neither precise nor properly documented. We must not forget that the state exercises strict controls on drugs. France has specialist agencies responsible for the health of patients and of controlling what information is given to them."

Professor Even told the Guardian most of the drugs criticised in the book are produced by French laboratories. He accused the pharmaceutical industry of pushing medicines at doctors who then push them on to patients. "The pharmaceutical industry is the most lucrative, the most cynical and the least ethical of all the industries," he said. "It is like an octopus with tentacles that has infiltrated all the decision making bodies, world health organisations, governments, parliaments, high administrations in health and hospitals and the medical profession.

"It has done this with the connivance, and occasionally the corruption of the medical profession. I am not just talking about medicines but the whole of medicine. It is the pharmaceutical industry that now outlines the entire medical landscape in our country."

The French consume medication worth €36bn (£29bn) every year, about €532 (£430) for each citizen who has an average 47 boxes of medicine in cupboards every year. The state covers 77% of the cost; in Britain spending on medicines is around £271 per person. "Yet in the UK people have the same life expectancy of around 80 years and are no less healthy," said Even.

The authors were commissioned by former President Nicolas Sarkozy to write a report over the Mediator affair, a drug developed for diabetes patients but prescribed as a slimming aid, that has been linked to the deaths of hundreds of patients who developed heart problems.

However, Even accused the industry of having a get-rich-quick attitude to making medicines and said it was interested in chasing only easy profits. "They haven't discovered very much new for the last 30 years, but have multiplied production, using tricks and lies.

"Sadly, none of them is interested in making drugs for rare conditions or, say, for an infectious disease in countries with no money, because it's not a big market. Nor are they interested in developing drugs for conditions like Alzheimer's or Parkinson's disease because it too difficult and there's not money to be made quickly.

"It has become interested only in the immediate, in short term gains. On Wall Street, the pharmaceutical industry is third after petrol and banking, and each year it increases by 20%. It's more profitable than mining for diamonds."

Asked to explain French people's apparent dependence on medication, Even said: "For the last 40 years patients have been told that medicines are necessary for them, so they ask for them. Today we have doctors who want to give people medicines and sick people asking for medicines. There's nothing objective or realistic about this."

He added: "There is nothing revolutionary in this book. This has all been known for some time."

• This article was amended on 17 September 2012 to correct the figures given for health spending. The original article gave overall health spending figures and not spending on medicines.