Blood pressure drug may stop cocaine, alcohol addiction

Giving hopes to millions of addicts around the world, a drug helpful in treating high blood pressure is now effective in ceasing cocaine and alcohol addiction in animal models, new research says.

If the treatment is proven effective in humans, the drug called isradipine would be the first of its kind - one that could help prevent relapses - by erasing the unconscious memories that underlie addiction, the study said.

"This drug might help the addicted brain become de-addicted," said lead researcher Hitoshi Morikawa, associate professor of neuroscience at The University of Texas at Austin.

For the study, the researchers trained rats to associate either a black or white room with the use of a drug.

Subsequently, when the addicted rats were offered the choice of going into either room, they nearly always chose the room they associated with their addiction.

Then one day, the researchers gave the addicted rats a high dose of an anti-hypertensive drug called isradipine before the rats made their choices.

Although rats still preferred the room they associated with their addiction on that day, they no longer showed a preference for it on subsequent days.

"The isradipine erased memories that led them to associate a certain room with cocaine or alcohol," Morikawa said.

Addictive drugs are thought to rewire brain circuits involved in reward learning, forming powerful memories of drug-related cues.

Anti-hypertensive drugs all block a particular type of ion channel, which is expressed not only in heart and blood vessels but also in certain brain cells.

The researchers found that blocking these ion channels in brain cells, using isradipine, appears to reverse the rewiring that underlies memories of addiction-associated places.

Morikawa said that because isradipine is already labelled as safe for human use by the U.S. Food and Drug Administration (FDA), clinical trials could potentially be carried out much more quickly than with non-approved drugs.

The research was published in the journal Molecular Psychiatry.