New CDC Study: 8mg Kloxxado and 4mg Narcan are equally effective

New study: Kloxxado vs. Narcan

Result: No difference

The Centers for Disease Control published a study today reporting that 8mg nasal naloxone (Kloxxado) has no benefit over 4mg nasal naloxone (Narcan) when measured by survival rates, number of doses received, hospitalization refusals or combativeness of person reversed. The 8mg naloxone did produce a negative effect: when compared to 4mg naloxone:  a significant increase in the prevalence of withdrawal symptoms.

The study is important because it challenges the value of a “naloxone arms race” underway in recent years. The pharmaceutical industry has been releasing new products with increasing naloxone per doses without evidence that higher doses have any value, despite often costing more or being promoted as more effective.

The CDC said more research is needed to settle the issue. But this study, the most rigorous yet, challenges the idea that “more is better” when it comes to naloxone and indicates more may be worse in at least one respect, i.e., causing additional withdrawal symptoms.

Click to read study

Hikma Pharmaceuticals manufacturers Kloxxado and other drugs at a large plant on the west side of Columbus.

The CDC study compared the effectiveness of Kloxxado and Narcan in 350 overdose reversal attempts done by law enforcement in New York.

Bottom line: This study provides support for the idea that 4mg naloxone nasal is a better choice than 8mg naloxone. It has the same benefits without causing additional sickness from withdrawal symptoms.

What study found

The CDC study was published in its weekly journal, Morbidity and Mortality Report. The CDC summary of the study said:


Among recipients of 4-mg or 8-mg intranasal naloxone administered by law enforcement, no differences were observed in survival, the number of doses received, prevalence of most postnaloxone signs and symptoms, combativeness, or hospital transport refusal; 8-mg product recipients had a significantly higher prevalence of opioid withdrawal signs and symptoms than did 4-mg product recipients.


No benefits to administration of 8-mg intranasal naloxone compared with 4-mg product were found. More data are needed to determine whether higher-dose intranasal naloxone would provide added benefits.

HARM REDUCTION OHIO says: We provide both 4mg and 8mg naloxone naloxone, based on what is requested by individuals, and will continue to do so for foreseeable future. However, this study supports the idea that 4mg naloxone (Narcan or generic) is a superior choice to 8mg Kloxxado. We encourage people who order and use naloxone to consider this.

A new 3mg naloxone is also on the market. That may soon be a consumer option that Harm Reduction Ohio provides.

Dennis Cauchon

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