Treatment needs to be regularly reviewed, the report says
MPs have urged the government to stop the "dangerous over-prescribing" of antipsychotic drugs to people in care homes with dementia.
The All Party Parliamentary Group on Dementia said the drugs should only be used as a last resort.
Research published earlier this month said the drugs had no benefits, and could even worsen patients' condition.
Alzheimer's groups said safeguards should be introduced to ensure the drugs were used only when essential.
There are currently 700,000 people with dementia in the UK, but that figure is predicted to soar to well over 1.7m by 2051.
The recent study, by experts from Kings College London and Oxford and Newcastle Universities, found the drugs provided no benefit for patients with mild behavioural problems, but were associated with a significant deterioration in verbal skills.
Side effects previously cited include excessive sedation, dizziness social withdrawal, accelerated cognitive decline and severe sensitivity reactions.
There have also been suggestions that use of two of the drugs, risperidone and olanzapine, can increase the risk of stroke.
The committee looked at the prescription of antipsychotics to care home residents.
It concluded that around 70% of prescriptions are inappropriate, equating to around 105,000 people with dementia.
People also often stayed on the medication for far longer than was necessary, it concluded.
The MPs propose a five-point plan to address the issue for inclusion in the government's National Dementia Strategy, due to be published later this year.
- Specialist dementia training for all care home staff
- Families to be involved in all decisions about giving the drugs
- More support for care home staff from GPs, psychiatrists and psychiatric nurses
- Compulsory patient reviews every 12 weeks
- A cost-effectiveness review by NICE, the National Institute of Health and Clinical Excellence and a national audit by the Care Quality Commission, which supervises care homes
Jeremy Wright MP, chairman of the group, said: "The government must end this needless abuse and make the five-point-plan a key element of the strategy.
"Safeguards must be put in place to ensure antipsychotics are always a last resort."
He added: "We need to include families in decisions, give people with dementia regular reviews and equip care staff with specialist training."
One carer said the home where his wife resided sent for him because she had deteriorated rapidly
"We eventually got the GP out and he admitted that he did not know what to do.
"He suggested that he should ask the consultant to visit and see what he could do to help my wife. It took five months to get him to visit the home by which time my wife's health deteriorated.
"When he saw what medication she was on he immediately arranged to have her taken off all antipsychotic drugs."
Alzheimer's experts said more than 70% of people with dementia displayed some form of challenging behaviour at some point, but that it was often a way of expressing themselves, and so they should not automatically be offered drugs.
Neil Hunt, chief executive of the Alzheimer's Society, said: "It is absolutely disgraceful that widespread abuse of people with dementia has been allowed to continue despite safety warnings on antipsychotics. Urgent action is needed."
Rebecca Wood, chief executive of the Alzheimer's Research Trust, added: "The report highlights the urgent need to develop better treatments for Alzheimer's.
"With more research funding, we could produce better drugs that are fit for purpose."
Ivan Lewis, care services minister, said: "The All-Party report raises issues of serious concern. Inappropriate administration of medication is entirely unacceptable.
"Guidance to health professionals and care staff is very clear, antipsychotic drugs should only be used when they are appropriate as part of best clinical care practice."
He said the dementia strategy would address the issue of medication and seek to protect people with dementia from poor professional practice.
The drugs concerned are haloperidol, chlorpromazine, risperidone, olanzapine, quetiapine and amisulpiride.