Can we cure malaria with blood pressure medicine?
Malaria is caused by a crafty little parasite that has become resistant to many medicines. But now researchers at Northwestern University have discovered a chink in its armor – a blood pressure medicine called propranolol. Who knew that a common beta-blocker used to treat hypertension might provide the death blow to such a scourge?
Usually, malarial parasites infect their host’s blood stream through a mosquito bite, and then congregate in the liver and pounce on red blood cells as they pass by. They have a way of adhering to the red blood cells via certain surface receptors (beta 2 adrenergic receptors linked to Gs proteins). They latch on to the red cells and then burrow into the cell and hijack it in order to reproduce inside it. Then, like the horror movie Alien, once they’re fully grown (into “schizonts”) they burst out of the cells and roam free to repeat the process all over again.
Now propranolol happens to block the Gs proteins, which effectively makes it impossible for the parasites to attach themselves to the red blood cells (which they need to use to reproduce themselves).
So what’s the caveat to of all this? Well, folks don’t know they have been infected with malaria until they have symptoms, and the symptoms include high fevers and low blood pressure… so giving someone a medicine that lowers their blood pressure even further might not be a good idea.
The other caveat is that propranolol works like a charm in the test tube, and in mice, but we haven’t yet tried it out in humans who have malaria.
Still, it seems to me that a little bit of propranolol might go a long way to preventing malarial infections in at risk populations. I’ll be interested to see what further studies show!
And if you’re interested, I’ll create a few more blog posts about parasites and other creepy crawly human invaders… Just let me know if you can handle more of this!
This post originally appeared on Dr. Val’s blog at RevolutionHealth.com.
And then there was the recent 60 Minutes segment “A Pill To Forget?” on the use of Propranolol to treat, or actually prevent, Post-Traumatic Stress Disorder (PTSD). Studies on mice found that Propranolol blocked adrenaline – which makes memories much stronger. A small human study found that when taken soon after a traumatic event, it reduced signs of PTSD in those who took it, whereas those on a placebo didn’t get the same positive results.
The segment also explored the question of whether this memory-reducing treatment was medically ethical. I loved the response of the chief researcher Dr. Roger Pitman, a psychiatrist at Harvard Medical School – “Let’s suppose you have a person who comes in after a physical assault and they’ve had some bones broken, and they’re in intense pain. Should we deprive them of morphine because we might be taking away the full emotional experience? Who would ever argue that? Why should psychiatry be different? I think that somehow behind this argument lurks the notion that mental disorders are not the same as physical disorders. That treating them or not is more of an optional thing.”