Anaphylaxis

Development of neffy, an Epinephrine Nasal Spray, for Severe Allergic Reactions

Epinephrine autoinjectors (EAIs) are used for the treatment of severe allergic reactions in a community setting; however, their utility is limited by low prescription fulfillment rates, failure to carry, and failure to use due to fear of needles. Given that delayed administration of epinephrine is associated with increased morbidity/mortality, there has been a growing interest in developing needle-free, easy-to-use delivery devices. neffy (epinephrine nasal spray) consists of three Food and Drug Administration (FDA)-approved components: epinephrine, Intravail A3 (absorption enhancer), and a Unit Dose Spray (UDS). neffy's development pathway was established in conjunction with the FDA and the European Medicines Agency and included multiple clinical trials to evaluate pharmacokinetic and pharmacodynamic responses under a variety of conditions, such as self-administration and allergic and infectious rhinitis, as well as an animal anaphylaxis model of severe hypotension, where neffy demonstrated a pharmacokinetic profile that is within the range of approved injection products and a pharmacodynamic response that is as good or better than injections. The increased pulse rate (PR) and blood pressure (BP) observed even one minute following the administration of neffy confirm the activation of α and β adrenergic receptors, which are the key components of epinephrine's mechanism of action. The results suggest that neffy will provide a safe and effective needle-free option for the treatment of severe allergic reactions, including anaphylaxis.

Anaphylactic shock following intravenous administration of lignocaine

A 26-year-old female, presenting for dental surgery, developed anaphylactic shock immediately after intravenous administration of lignocaine without preservative added to the propofol to alleviate pain during intravenous injection. We describe the clinical circumstances, the management and the investigations carried out to detect the cause.

Anaphylactic shock: mechanisms and treatment

This paper reviews the mechanisms of anaphylactic shock in terms of the immunoglobulin and non-immunoglobulin triggering events, and the cellular events based on the rise in intracellular cyclic AMP and calcium that release preformed granule-associated mediators and the rapidly formed, newly synthesized mediators predominantly based on arachidonic acid metabolism. These primary mediators recruit other cells with the release of secondary mediators that either potentiate or ultimately curtail the anaphylactic reaction. The roles of these mediators in the various causes of cardiovascular collapse are examined. The treatment of anaphylactic shock involves oxygen, adrenaline and fluids. The importance and safety of intravenous adrenaline are discussed. Combined H1 and H2 blocking antihistamines and steroids have a limited role. Glucagon and other adrenergic drugs are occasionally used, and several new experimental drugs are being developed.

Acute anaphylactic reactions

Anaphylactic shock may be provoked by a diverse group of substances and stimuli, which range from large molecular weight proteins and small drug molecules to some colloids, emulsions and even exercise. The underlying mechanism may be immunological or non-immunological but, regardless of the mechanism, the physiological effects and the observable symptoms of anaphylaxis are due to the release of potent pharmacologically-active mediators, including histamine. Although a number of predisposing factors are recognized, the appearance of most of the reactions cannot be predicted. Reactions occur suddenly and dramatically and progress rapidly. Cardiovascular collapse is the most common life-threatening clinical feature, while bronchospasm is the most difficult to treat. The primary aim of treatment should be to treat the underlying cause and to improve cellular oxygenation. The pharmacological agent of choice for treatment is adrenaline. It is direct-acting and is effective for both bronchospasm and cardiovascular collapse. It is imperative that the provoking substance or stimulus be identified in patients and there is no substitute for a carefully-gathered and detailed case history in the diagnosis of anaphylaxis. Patients should be issued with some form of warning identification together with written details concerning their reaction.