Epinephrine Auto-Injector Needle Length (Does Height or BMI add Valuable Information in Adults?)

Allergy Asthma Clin Immunol

2022

Self Cite

Background In anaphylaxis, the dosing of injectable epinephrine in medical settings has been arbitrarily recommended to be 0.01 mg/kg of body weight. For ethical reasons, there have been no dose–response studies or double-blind studies performed on patients with active anaphylaxis. Intramuscular delivery of epinephrine has been the standard. Auto-injectors for use in the treatment of anaphylaxis are available in four strengths (0.1, 0.15, 0.3, and 0.5 mg). However, in many countries, only the 0.15 and 0.3 mg strengths are available. Consequently, many adult, heavy patients are prescribed the 0.3 mg dose, which may result in only one-fifth to one-third of the recommended weight-based dose being administered in heavy patients experiencing anaphylaxis. Underdosing may have therefore contributed to mortality in anaphylaxis. Objective To review the doses of epinephrine recommended for the treatment of anaphylaxis in the community, and assess whether recommendations should be made to increase dosing for heavy adult patients in hopes of avoiding future deaths from anaphylaxis. Methods We reviewed multiple national and international recommendations for the dosing of epinephrine. We also reviewed the literature on adverse drug reactions from epinephrine, lethal doses of epinephrine, and epinephrine dose-finding studies. Results The majority of national and regional professional societies and authorities recommend epinephrine delivered by auto-injectors at doses far lower than the generally accepted therapeutic dose of 0.01 mg/kg body weight. Furthermore, we found that the recommendations vary even within regions themselves. Conclusions We suggest prescribing more appropriate doses of epinephrine auto-injectors based on weight-based recommendations. There may be some exceptions, such as for patients with heart disease. We hypothesize that these recommendations will lead to improved outcomes of anaphylaxis.

Section: Properties and Dosing Of Epinephrinementioning

confidence: 99%

“…Likewise, the 0.5 mg dosing should be tolerated by adolescents and young adults weighing more than 40 kg. Healthy adults weighing more than 50 kg would likely benefit from the 0.5 mg dose [ 11 ] (Table 5 and Fig. 3 ).…”

Section: Practical Clinical Implicationsmentioning

confidence: 99%

International recommendations on epinephrine auto-injector doses often differ from standard weight-based guidance: a review and clinical proposals

Dreborg

Walter

Allergy Asthma Clin Immunol

2022

Self Cite

The pharmacokinetics of epinephrine/adrenaline autoinjectors

Dreborg

Allergy Asthma Clin Immunol

2021

Background For a century, epinephrine has been the drug of choice for acute treatment of systemic allergic reactions/anaphylaxis. For 40 years, autoinjectors have been used for the treatment of anaphylaxis. Over the last 20 years, intramuscular epinephrine injected into the thigh has been recommended for optimal effect. Objective To review the literature on pharmacokinetics of epinephrine autoinjectors. Results Six studies assessing epinephrine autoinjector pharmacokinetics were identified. The studies, all on healthy volunteers, were completed by Simons, Edwards, Duvauchelle, Worm and Turner over the span of 2 decades. Simons et al. published two small studies that suggested that intramuscular injection was superior to subcutaneous injection. These findings were partially supported by Duvauchelle. Duvauchelle showed a proportional increase in Cmax and AUC0-20 when increasing the dose from 0.3 to 0.5 mg epinephrine intramuscularly. Turner confirmed these findings. Simons, Edwards and Duvauchelle documented the impact of epinephrine on heart rate and blood pressure. Turner confirmed a dose-dependent increase in heart rate, cardiac output and stroke volume. Based on limited data, confirmed intramuscular injections appeared to lead to faster Cmax. Two discernable Cmax’s were identified in most of the studies. We identified similarities and discrepancies in a number of variables in the aforementioned studies. Conclusions Intramuscular injection with higher doses of epinephrine appears to lead to a higher Cmax. There is a dose dependent increase in plasma concentration and AUC0-20. Most investigators found two Cmax’s with Tmax 5–10 min and 30–50 min, respectively. There is a need for conclusive trials to evaluate the differences between intramuscular and subcutaneous injections with the epinephrine delivery site confirmed with ultrasound.

Epinephrine autoinjectors: individualizing device and dosage to optimize anaphylaxis management in the community setting

Alizadehfar

Alqurashi

et al. 2023

allergy asthma proc

Background: Anaphylaxis is the most severe manifestation of a systemic allergic reaction, and, in the community setting, the immediate administration of an epinephrine autoinjector (EAI) can be life-saving. Physicians are tasked with selecting the most appropriate EAI for each individual and counseling patients and/or their caregivers to maximize the likelihood of successful deployment of the EAI. Objective: To offer an evidence-based expert clinical perspective on how physicians might best tailor EAI selection to their patients with anaphylaxis. Methods: A group of eight adult and pediatric allergists with expertise in anaphylaxis management reviewed and assessed the published data and guidelines on anaphylaxis management and EAI device selection. Results: Personalized EAI selection is influenced by intrinsic individual factors, extrinsic factors such as the properties of the individual EAI (e.g., dose, needle length, overall design) as well as cost and coverage. The number and the variety of EAIs available have expanded in most jurisdictions in recent years, which provide a greater diversity of options to meet the characteristics and needs of patients with anaphylaxis. Conclusion: There currently are no EAIs with customizable dose and needle length. Although precise personalization of each patient's EAI remains an optimistic future aspiration, careful consideration of all variables when prescribing EAIs can support optimal management of anaphylaxis.