Inhaled blood pressure drug shows promise in treating anxiety and pain

The inhaled version of a high blood pressure drug may treat anxiety.

The inhaled form of a high blood pressure drug may treat some types of anxiety and pain, according to a new study by Canada’s Centre for Addiction and Mental Health (CAMH).

The medication amiloride – a short-acting nasal spray – is said to offer a new approach to prevent anxiety attacks and relieve pain. Anxiety disorders are usually treated with medications, such as antidepressants, and psychotherapy.

Lead author Dr Marco Battaglia said: “Inhaled amiloride may prove to have benefits for panic disorder, which is typically characterised by spells of shortness of breath and fear, when people feel anxiety levels rising.”

The research focused on amiloride because it influences key physiological changes in brain functioning linked to anxiety and pain sensitivity, said Dr Battaglia, who is CAMH’s Associate Chief of Child and Youth Psychiatry and Clinician Scientist in the Campbell Family Mental Health Research Institute.

Immediate access to brain

Amiloride was inhaled so that it could immediately access the brain. The research showed that the medication reduced the physical respiratory signs of anxiety and pain. This therapeutic effect didn’t occur when amiloride was administered in the body, because it did not cross the blood-brain barrier and, therefore, did not reach the brain.

The study was based on years of research into how early life experiences affected genes, said Dr Battaglia. Childhood trauma, such as loss or separation from parents, were said to increase the risk of anxiety disorders and pain, among other health issues, in later life. Such negative experiences, at a molecular level, were linked to changes in some genes of the ASIC (acid-sensing-ion-channels) group that were said to affect the way DNA functions.

The information contained in DNA synthesises working proteins through a process called gene expression. Due to childhood adversity, some ASIC genes showed increased expression and epigenomic changes, which were linked to physical symptoms. Breathing can be affected, due to over-sensitivity to higher carbon dioxide levels in the air, said Dr Battaglia. In such situations, a person might hyperventilate and experience growing anxiety and amiloride turned out to be very effective in treating this.

Eases anxiety symptoms

The next step was to test whether amiloride eases anxiety symptoms, said Dr Battaglia. He is conducting a pilot clinical trial, supported by funding from CAMH’s new Discovery Fund. Partners at the University of Utah are testing the drug’s safety.

Amiloride had been used as an oral treatment for hypertension for many years, said Dr Battaglia, and had also featured in several experimental studies of cystic fibrosis. That meant researchers could benefit from a range of studies into the medication.

The results of the study were published in the Journal of Psychopharmacology.

Meanwhile, CAMH is Canada’s largest mental health and addiction teaching hospital and a world-leading research centre in this field. It combines clinical care, research, education, policy development and health promotion to help people affected by mental illness and addiction.