Using common medicines such as antibiotics, acne pills and other drugs could be used to fight against dementia as developing new drugs is too costly and slow, suggest experts.
According to experts, it is time to re-examine medicines already in circulation as cheaper, quicker alternatives to new treatments.
Many have multiple effects on the body, so some could be able to ease the effects of Alzheimer's and other forms of dementia.
There are only four Alzheimer's drugs in use which can help relieve symptoms but do nothing to stop damage to the brain.
"Defeating dementia is one of the biggest challenges facing both medicine and society as a whole," the Daily Mail quoted Professor Clive Ballard as saying.
"Developing new drugs is incredibly important but it comes with a huge price tag and, for those affected by dementia, an unimaginable wait," Ballard said.
It can take up to 20 years and 600 million pounds to create a drug from scratch. Hopes of quickly adding to available treatments were recently dashed when several promising new ones failed the final stage of testing.
So Mr Ballard, professor of age-related diseases at King's College London, and other experts turned to the possibility of using everyday drugs.
They drew up a short-list, which includes liraglutide - a diabetes treatment that also acts on the brain.
Others include minocycline, an antibiotic for acne, and acitretin, which treats the skin condition psoriasis. There is also a family of blood pressure drugs called calcium channel blockers.
Some of these medicines cost less than 50p a tablet.
"The idea that drugs for other conditions could fight Alzheimer's is appealing," Rebecca Wood, chief executive of Alzheimer's Research UK, said.
"But it's not yet clear that such a drug exists. Alzheimer's is a complex disease with many risk factors," Wood added.
The study has been published in the journal Nature Reviews Drug Discovery.