People with dementia who use antipsychotic drugs have a higher risk for serious adverse outcomes such as stroke, blood clots, heart attack, heart failure, fracture, pneumonia and acute kidney injury, according to a study published Tuesday in The BMJ today.
Authors said that the findings show there are more dangers linked to antipsychotic drugs in people with dementia than previously acknowledged. The highest risks occur soon after a person starts taking the medications.
Antipsychotics are usually prescribed for behavioral and psychological symptoms of dementia such as anxiety, depression, aggression, irritability, delirium and psychosis. Warnings on the labels of the medication call out risks for stroke and death, but the other adverse outcomes aren’t as well advertised.
Researchers looked at the drug and its link to outcomes such as stroke, major blood clots (venous thromboembolism), heart attack (myocardial infarction), heart failure, irregular heart rhythm (ventricular arrhythmia), fractures, pneumonia and acute kidney injury. Data came from 173,910 people in England who were diagnosed with dementia at an average age of 82 between January 1998 and May 2018. The people weren’t prescribed antipsychotic drugs in the year before they were diagnosed.
A total of 35,339 people on antipsychotics on or after the date of their dementia diagnosis were matched with up to 15 randomly selected patients who hadn’t taken the drugs. Risperidone, quetiapine, haloperidol and olanzapine were most commonly prescribed. Those made up about 80% of all prescriptions.
People on the drugs had increased risks for all of the outcomes except ventricular arrhythmia. During the first three months of starting a drug, rates of pneumonia among antipsychotic users were 4.48% compared to 1.49% for non-users. After one year, the numbers rose to 10.41% for antipsychotic users versus 5.63% for non-users.
Older adults with dementia had a 1.7-fold increased risk for acute kidney injury and a 1.6-fold increased risk for stroke and venous thromboembolism if they took the drugs compared to those who didn’t.
For almost all of the adverse outcomes, the risks were highest — particularly for pneumonia — during the first week of starting an antipsychotic. During the first six months of starting an antipsychotic, the drug was linked to one additional case of pneumonia for every nine people treated, and one additional heart attack for every 167 people treated. After two years, there was one additional case of pneumonia for every 15 people treated, and one additional heart attack for every 254 people who took the drugs.
Any potential benefits of antipsychotic treatment need to be weighed against risk of serious harm. Doctors should review treatment plans regularly if they put someone with dementia on the medications.
