Some asthma medications, including the drug salbutamol (also known as albuterol and marketed as Ventolin among other names), may have the potential to treat or reduce the risk of developing Parkinson’s disease (PD). Recent research from Norway and Harvard University has revealed these potentially significant results. PD, a chronic, progressive movement disorder that affects at least a half-million Americans, has no single cause or known cure.
How asthma medications work
Inhaled medications that expand airways are used to treat asthma and other breathing condition, like COPD. They relieve symptoms such as coughing, wheezing, and feeling breathless. Salbutamol “turns on” a protein receptor that relaxes airway muscles and makes breathing easier.
Details of the Norweigan study
A study at the University of Bergen in Norway found some asthma medicines with the potential to treat or help prevent PD. More than 1,000 medications were tested. Three were identified as having potentially significant results – salbutamol, clenbuterol, and metaproterenol.
To see how the drugs affected rates of Parkinson’s development researchers needed a large database of prescriptions and health records. Norway, which offers universal health care, keeps a database of all citizens’ drugs and diseases. The study population included all individuals living in Norway on January 1, 2004, a total of 4.6 million people. They were able to review 11 years of records, through 2015. The findings indicated that salbutamol was associated with a decreased risk for PD. Patients using salbutamol were 34% less likely to develop PD.
The findings from the Norwegian study combined with research conducted at Harvard examined the effects of these drugs on human brain cells in the lab and on the substantia nigra portion of the brain in mice. Three of the 4 drugs work in the same ways and yielded the same effects. They all bind to the beta2-adrenoreceptor. In addition to salbutamol, clenbuterol and metaproterenol have similar effects on the body.
According to Dr. Scherzer from Harvard, the scientists evaluated other asthma drugs looking for the same results. They tested corticosteroids, a completely different class of asthma medication, and found no effect on the relation to developing PD. The results were specific to salbutamol.
Relation to Parkinson’s disease
Parkinson’s is a movement disorder that is caused by chemical changes in the brain. Clumps of protein can clog the area of the brain that controls movement. These clumps, known as Lewy bodies, contain damaged or excess alpha-synuclein proteins. PD researchers are studying ways to eliminate this protein, or at least prevent it from building up. Researchers were surprised to find that asthma drugs affected the same proteins in the brain that are associated with PD.
What was unique about this research study was that the specific asthma drugs reduced the production of alpha-synuclein in human nerve cells grown in the lab. All three drugs lowered the activity of the SNCA gene and reduced levels of alpha-synuclein protein.
But blood pressure medications increase risk?
In reviewing the entire Norwegian prescription database, researchers also looked at the blood pressure medication propranolol. They found that Norwegians with heart disease taking this beta-blocker were associated with a markedly increased risk for developing PD. Those who took propranolol were twice as likely to develop the disease.
The two drugs – salbutamol and propranolol – act on the same beta2-adrenoeceptor, with opposite effects. Salbutamol activates the receptor and propranolol blocks it. The active receptor lessens the activity of the SNCA gene and the production of alpha-synuclein.
The potential for using drugs developed for one condition to treat others is vast. Sometimes referred to as drug repurposing, medications that are already FDA approved and have known safety profiles might get to patients faster, although the FDA validates the efficacy for each desired use.
In the case of salbutamol and PD, future clinical trials will evaluate potential effectiveness as a treatment strategy. The research will examine whether the same association exists outside of Norway in a more diverse population. Similar findings from the epidemiological studies, animal experiments, and lab testing create reason for optimism.