A microchip which delivers drugs direct to a patient`s bloodstream on demand could replace regular injections in the next five years, it has been claimed.

The wirelessly operated microchip, which is wafer-thin and 1.3cm long, has been successfully tested on patients for the first time. The programmable device was used to store 20 doses of the drug teriparatide in tiny reservoirs, and could cut the number of injections carried out by those in nursing jobs.

The drug was released from each reservoir in the device at exactly the right time by a computer which was wirelessly linked to the implant. It was tested on seven women who suffer from osteoporosis aged between 65 and 70 years old.

In future, chips could be operated from far away and contain a range of drugs, the researchers claimed.

Professor Robert Langer from the Massachusetts Institute of Technology was one of the designers of the microchip. He said: "You could literally have a pharmacy on a chip. You can do remote control deliver, you can do pulsatile drug deliver, and you can deliver multiple drugs."

Copyright Press Association 2012