Acetaminophen Synergizes Through the CB1 Receptor

Acetaminophen and cannabinoid receptor interactions were the focus of a research article published in the journal of Neuropharmacology in late December 2009. The research demonstrates that the effects of Acetaminophen on pain are mediated through the CB1 receptor. Acetaminophen has previously been shown to elevate the levels of endocannabinoids in the body. Thus increasing the amount of activated cannabinoid receptors, leading to pain relief and anti-inflammatory effects.

Most prescription narcotics such as percocet and vicodin are cut with acetaminophen by pharmaceutical companies. This gives the pain killers more of a “kick.” Without acetaminophen, some pain killers are not nearly as effective. Researchers have been investigating the molecular mechanism for this interaction and the Endocannabinoid System appears to be a big player. Previous research has also shown that there is some “cross talk” between opiate receptors and cannabinoid receptors.

The study investigated the effects of acetaminophen in combination with different pain killers. The authors found that a combination of acetaminophen with gabapentin or morphine produced synergistic pain killing effects in rats.  The results may have clinical significance because the effect was observed in rats that are a model of spinal cord injury. Interestingly, this synergistic pain relief disappeared when the rats were given AM251. AM251 blocks the Cannabinoid Type 1 Receptor (CB1R) thus inhibiting CB1R activation.

Given the notable toxicity of acetaminophen,  cannabinoids might be a reasonable supplement to accompany current treatments for pain.

https://web.archive.org/web/20101111173104/http://cannabination.com/2010/01/03/acetaminophen-synergizes-through-the-cb1-receptor/