Toxins

The easily defanged myth that baby rattlesnakes (genera Crotalus and Sistrurus) are more dangerous than adults has persisted in North America despite all evidence to the contrary. The most often cited reason for the babies-more-dangerous (BMD) myth is the venom-dump (VD) hypothesis: babies, in contrast to adults, cannot control how much venom they expend, and therefore inject all of it when biting. We undertook three approaches to explore the origin, transmission, and prevalence of this myth and its most frequent explanation. First, we examined historical newspaper accounts. From 130 newspaper stories mentioning the relative danger of baby rattlesnakes, we identified a timeline in which (1) most stories prior to 1969 were factually correct; (2) the BMD myth and VD hypothesis likely originated in the mid-to-late 1960s and became entrenched in California, especially, from 1970 to 1999; (3) factually incorrect statements subsequently prevailed throughout North America from 2000 to 2014; and (4) factually correct stories regained prominence with apparent effective messaging success from 2015 onward. We further learned that general information stories about rattlesnakes, more often citing subject experts like university professors, were much more likely to provide accurate information than local snakebite stories, which more often cited health professionals (e.g., physicians, veterinarians, pharmacists) and emergency responders (e.g., police and fire officers) who frequently supplied misinformation. Second, we surveyed familiarity with the BMD myth and VD hypothesis among 53 university classrooms (including one high school) representing 3751 students across 29 states within the United States. Consistent with the California media’s outsized influence on misinformation transmission, familiarity with the myth was greatest in the southwestern states (52.6%) and declined moving north and east, with the least familiarity in the northeastern states (16.4%). Third, a small survey of 75 emergency responders and health professionals from Southern California revealed that a whopping 73.3% actually believed the BMD myth. Numerous organizations generally regarded as authoritative further amplified the misinformation, especially on the internet, where some content persists to this day. Unfortunately, belief in the BMD myth and VD hypothesis can lead to negative consequences, including misinformed risk-taking by those encountering snakes, unwarranted fear among snakebite victims, and inappropriate care delivered by misinformed or patient/family-pressured medical professionals. Our findings target health professionals and emergency responders as priority audiences for education.

Background: Chronic migraine (CM) is a highly disabling and difficult-to-manage condition with a high pharmacological and economic burden. OnabotulinumtoxinA (BTx) was the first treatment specifically approved for CM. The main aim of this study was to assess whether the initiation of BTx is associated with discontinuation of previously prescribed preventive therapies. Methods: This study was a prospective cohort investigation conducted in two headache centers: Carlo Besta (Milan) and Policlinico Campus Bio-Medico (Rome). We included patients with CM and previous oral preventive treatments initiating BTx. We analyzed persistence with preventive therapies over 12 months of follow-up and evaluated the conversion rate from chronic to episodic migraine (EM), along with change in migraine days, symptomatic intake, and HIT-6. Results: A total of 95 patients were included in the main analysis, showing a discontinuation of treatment in 28.4% of patients at 12 months. In the exploratory analysis, a CM to EM conversion rate of 58.9% was achieved at 12 months; meanwhile, HIT-6, migraine days, and symptomatic intake showed a sizeable improvement. Conclusion: Treatment with BTx was associated with a reduction in drug burden at 12 months and a CM to EM conversion rate of almost 60% at 12 months, also contributing to a reduction in the economic burden of the disease.

Botulinum neurotoxin type A (BoNT/A) is intramuscularly injected for the treatment of, e.g., spasticity, cervical dystonia or facial lines. Several BoNT/A products with or without complexing proteins, with non-interchangeable dose units and various duration of effect claims, are approved but hard to compare. The goal of this study was to compare the complexing protein-free approved BoNT/A products IncobotulinumtoxinA (INCO), DaxibotulinumtoxinA (DAXI) and RelabotulinumtoxinA (RELA) in vitro and in vivo. BoNT/A protein content per 100 U was lowest in INCO and highest in DAXI (INCO 0.44, RELA 0.46, DAXI 0.58 ng/100 U). Relative bioactivity of INCO, DAXI and RELA was comparable (116, 104 and 117 U/100 labeled units). INCO and DAXI caused a maximum mouse digit abduction score (DAS) 2–3 days after IM injection of 20 or 40 U/kg. The DAS after 20 U/kg INCO was higher and showed a 10 days longer paralysis than DAXI at equivalent dosing. The in vivo spread of DAXI in the mouse gastrocnemius muscle was indistinguishable from that after INCO, and the spread of RELA ex vivo in porcine muscle was larger than INCO but equal to 0.9% NaCl. These results show the differences between 150 kDa botulinum type A toxin products beyond the published claims.