It is not unusual for a person’s blood pressure to fluctuate when they are in the hospital, but having blood pressure medications prescribed or increased upon discharge may do more harm than good, suggests a new study, especially among older patients.

During a hospital stay, blood pressure is measured often, and it typically varies in response to illness, pain, anxiety or new medications. Doctors may increase blood pressure medications in patients without fully knowing a patient’s prior medication history, drug intolerances or barriers to medication adherence and disease control.

People who were discharged on more blood pressure medication experienced more medication-related events such as falls, fainting and acute kidney injury.

National VA and Medicare information on over 4,000 veterans age 65 or older formed the basis of the study by researchers at the University of California San Francisco and the San Francisco VA Health Care System. All had high blood pressure and had been hospitalized for non-cardiac problems that don’t normally require intensive treatment for high blood pressure. Half of the patients in the study were discharged from the hospital on higher doses of blood pressure medications and half were not.

People who were discharged on more blood pressure medication had a higher risk for readmission to the hospital at 30 days after discharge than those who were not given additional blood pressure medication. They also experienced more medication-related events such as falls, fainting and acute kidney injury.

Veterans who were given increased doses of blood pressure medications had no reduction in blood pressure or rate of readmission to the hospital for cardiovascular conditions, compared to patients who did not go home on higher doses of blood pressure medications, so the medications served no purpose.

Timothy Anderson, lead author of the study, explained that blood pressure control is long-term, and these findings suggest that making medication changes during a hospital stay potentially does more harm than good. Rather than prescribing increased doses of blood pressure medications, physicians should let the patient’s outpatient doctor know about higher pressure readings during a hospital stay so they can make decisions about further management, the study authors believe.

Though the findings relate to blood pressure medications, changing other medications during a hospital stay that patients take for chronic conditions may also not be a good idea, Dr. Anderson explained.

Be aware of and ask questions about all of the medications you are sent home with upon discharge from the hospital. Understand the potential side effects of the medications you take, and report any unusual changes or events to your primary care physician immediately.

The study is published in JAMA Internal Medicine.