New Painkiller on the Market: The Good and the Not So Good

‍Summary

• The medicine is sold as Journavx, with the chemical name Suzetrigine.
• It works by blocking NaV1.8 channels, which are responsible for pain transmission along nerves.
• It only affects peripheral nerves (outside the brain and spinal cord), such as those in the arms and legs.
• It does not cause addiction.
• However, Journavx is weaker than Vicodin in controlling pain.
• It is more effective for acute post-operative pain but not for chronic pain.
• It failed in the treatment of low back pain.

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What is Suzetrigine?

Suzetrigine, marketed under the brand name Journavx, is a novel non-opioid analgesic recently approved by the U.S. Food and Drug Administration (FDA) for the treatment of moderate-to-severe acute pain in adults. Developed by Vertex Pharmaceuticals, Suzetrigine represents the first new class of pain medication approved in over two decades.

Mechanism of Action

Suzetrigine functions as a selective inhibitor of the NaV1.8 sodium channel, which is predominantly expressed in peripheral pain-sensing neurons (nociceptors). By targeting this specific channel, Suzetrigine modulates pain transmission without affecting the central nervous system (CNS), thereby reducing the risk of addiction associated with opioid therapies.

Clinical Efficacy

The efficacy of Suzetrigine was demonstrated in two randomized, double-blind, placebo- and active-controlled trials involving patients undergoing abdominoplasty and bunionectomy surgeries. In both studies:

• Patients receiving Suzetrigine reported a significant reduction in pain compared to those receiving a placebo.
• However, Suzetrigine did not outperform opioids (hydrocodone and acetaminophen) in pain relief.
• While not as strong as opioids, it provided effective pain relief without the risks of addiction.

Benefits

• Non-Opioid Alternative: A new option for acute pain management without the risk of opioid addiction.
• Targeted Mechanism: By selectively inhibiting the NaV1.8 sodium channel, Suzetrigine specifically modulates pain signals in peripheral neurons, potentially leading to fewer CNS side effects.

Risks and Adverse Effects

In clinical trials, the most commonly reported adverse reactions included:

• Itching
• Muscle spasms
• Elevated blood levels of creatine phosphokinase
• Rash

Suzetrigine is contraindicated with strong CYP3A inhibitors. Patients are also advised to avoid consuming grapefruit products during treatment due to potential drug interactions.

Considerations

While Suzetrigine has shown promise in acute pain management, its effectiveness in chronic pain conditions is questionable.

• A Phase 2 study on lumbosacral radiculopathy did not show significant benefits over a placebo.
• This highlights the limitations of Suzetrigine in chronic pain and the need for further research.

Conclusion

In summary, Suzetrigine is not a very impressive painkiller. It has weak pain-relieving properties, is only effective in acute surgical pain, and does not work for chronic pain. As with any medication, its benefits should be weighed against its potential risks, and individual patient needs must be considered when determining the best pain management strategy.

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