The NHS could save up to £800 million if PCTs supported implementation of NICE guidance more fully, a review by the institute has suggested.
NICE has identified guidelines in 19 areas which could each save millions of pounds.
Around £295 million could be saved from depression and anxiety services, £273 million from hypertension treatment and £130 million from family planning services, it believes.
'NICE is committed to working hard to support PCTs and NHS providers to make best use of their money over the next few years, making the case for investment and disinvestment through our guidance programmes,' it said.
NICE suggests that following its hypertension guideline (CG34) will increase drug spending, but that this will be 'far outweighed' by savings from reducing MIs and strokes.
West London GP and British Cardiology Society member Dr Sarah Jarvis said there was good evidence that spending more on medicines would help to improve patient outcomes.
'One of the big problems is that GPs are being encouraged to use cheaper drugs but many patients do not take these drugs because of the side-effects,' she said.
'Within a year most patients given diuretics or calcium channel blockers will have stopped taking them. Drugs only work if you take them.'
NICE also predicted savings of £130 million from increased uptake of long-acting reversible contraceptives (LARCs).
'The additional cost of these methods is more than offset by the costs of unplanned pregnancies,' it said.
North London GP Dr Richard Ma, of the RCGP's sex, drugs and HIV working party, said that initial investment in providing LARCs would reap benefits in the future.
'PCTs and commissioners should be looking at the long-term effects,' he said.
'The hurdle will be achieving sufficient capacity for the provision of LARCs,' he added. 'In some places there are waiting lists. In others training places for GPs may be restricted. PCTs need to develop innovative training processes locally to help improve uptake of LARCs.'