Researchers have written to senior health officials warning them that starch-based IV fluids used "widely" across the health service increase patients' risk of death.
Healthcare providers should stop using starch-based colloid solutions because they are causing "unnecessary deaths", they said.
The authors estimate that the drips, which are used to stabilise patients with low blood pressure, could be causing around 250 unnecessary deaths in the UK every year. They argue that starch-based colloid fluids cost more than saline-based crystalloid fluids and also increase patients' risk of death by 10%.
A Cochrane systematic review, of 25 different trials, examined data from 9,147 patients who either suffered trauma, burns, underwent surgery or had severe infections and were randomly allocated both types of the intravenous fluid.
The researchers, from the London School of Hygiene and Tropical Medicine, found that those given the starch-based drips had a higher chance of dying than patients who received saline drips.
The safety of IV fluids containing hydroxyethyl starch has been debated for years and is currently being investigated by the European Medicines Agency. But the researchers say that the NHS must take action now to prevent more unnecessary deaths.
Lead author Dr Ian Roberts, director of the clinical trials unit at the London School of Hygiene and Tropical Medicine, has written to NHS medical director Professor Sir Bruce Keogh asking him to consider the implications of using starch solutions in the health service.
"Starch solutions are widely used in the NHS and the evidence from our study shows that they kill patients," he said.
"They are more expensive than saline and they increase the risk of death. British hospitals use far more starch solutions than most other countries. The ongoing use of colloids is unjustified.
"We don't need to wait for starch solutions to be banned in order to take action in the NHS. We have a safer, less expensive alternative that is widely used around the world. The NHS should take action now."