Drug Allergy- Taiya Duke

Emily was given ampicillin and amoxicillin to heal the lesions in her mouth to prevent endocarditis prior to dental work on cavities. She was given antibiotics 3 times (First, IV then second and third times orally).

The first time she was administered IV ampicillin she became sensitized. This means the beta lactam compound was introduced into the blood stream, then antigen presenting cells (APC) sensed their presence, recognised it as an antigen, and notified the T helpers cells. The beta lactam antigen’s information was shared and triggered an adaptive response which includes the B Cells. The B cells develop into plasma cells to make antibodies, IgE, to protect against the beta lactam antigens if exposed again. IgE antibodies attach themselves to mast cells and basophils where they floated freely in the body. They create memory cells for the next interaction with the beta lactam antigen. At this stage there are no symptoms.

The 2^nd time Emily had amoxicillin the APC recognized the beta lactam antigen, which notified T helper cells to cause B cells to release IgE to trigger a response, but the body wasn’t ready yet to respond. The antibodies are re-sensitized and ready to react to another exposure.

The 3^rd time receiving amoxicillin (effector stage), the mast cells and basophils that have the pre-existing IgE within them are ready to respond. Once APC identified the beta lactam antigen, they notified the T helper cells which causes B cells to increase production of even more IgE. Additionally, other available floating antibodies in the body attach to the beta lactam antigen receptor site which activates a cellular response of increased production of B cells. Once the antigen binds to the IgE attached to the mast cells and basophils it causes the cell to burst. Inside the cells were inflammatory mediators such as histamine, cytokines and prostaglandin. The mediators trigger a vascular effect which causes dilation and permeability of the blood vessels. The accumulation of fluid in the vascular space causes fluid to leak out into the interstitial space causing the leukocytes to be released and travel to the site of the antigen.

Symptoms include pruritus of the foot, swelling of the airway and facial features, such as the lips, tongue and throat, urticaria, angioedema, hypotension and anaphylaxis in some cases. The symptoms developed within 30-60 minutes.

Treatment was diphenhydramine to assist with swelling. Ongoing monitoring was important post reaction to ensure her airway, blood pressure and heart rate was stable. IgE levels were checked later intradermally to confirm allergy and Emily was educated to stay away from ampicillin in the future.

I enjoyed the podcast being in a true crime story line as I felt like it was more engaging, easy to understand and fun to listen to.  It assisted me with understanding the concept, symptoms and treatment. I found the repetition of side effects throughout the podcast helped me make connections to what was happening in Emily’s body. When I first watched it the pathophysiology of hypersensitivity 1 reaction came back to me. I remembered that this reaction includes 2 stages: sensitization (asymptomatic) and effector (symptomatic) and the onset of each stage. I also remembered why it is very important to monitor after an allergic reaction; to keep an eye out for biphasic reaction if it was severe (anaphylactic) and to help treat symptoms.  I felt like the time restraint may have prevented more detail in certain topics, which was understandable. A potential addition I was thinking about would be to include a discussion of whether this was a true drug allergic reaction versus a sensitivity. Since you mentioned there was an increase of IgE present you could further discuss the differences between the two. I remember learning that only a small population has a true allergy to penicillin. Emily only had one dose of ampicillin and two doses of amoxicillin. How do we know she’s allergic to both?  I like how you added the purpose of penicillin and amoxicillin but some more information about how someone allergic to penicillin may also react to amoxicillin due to their similar structure may be beneficial. I also would have liked to know about more treatment options. Diphenhydramine was mentioned which was the main treatment, but I was also curious whether any other treatments were given to Emily to help her other symptoms. Perhaps puffers and oxygen could be required as an intervention. Lastly, since Emily was young, I was thinking that another intervention that nurses can suggest to assist her with preventing future reactions would be wearing a medical identification bracelet. I feel that a bracelet would be beneficial for all individuals with known allergies as it notifies the public of their allergies in case they are unable to vocalize.

One learning strategy that supported my learning was making a realistic scenario in a storyline presentation that could happen to any of our patients. Now a days antibiotics are used more frequently to fight infections or used prophylactically prior to a procedure. Penicillin is an antibiotic that is commonly known for causing drug allergic reactions or sensitivity in many people. It is important for nurses to understand how a drug allergic reaction can develop, to be able to identify them, treat them and help prevent it. The diagnosis of cavities and increased risk factor of endocarditis due to her history of heart disease was a good indication that antibiotics were necessary. I really liked how the story was divided in different phases throughout the podcast. At the beginning of the story, it started off with a broad overview of what to expect. This allowed me to get in the mind set of what generally occurs in a hypersensitivity 1 reaction. Then it was further broken down into more detail, like explaining more about Cillin the Villain and how the body’s adaptive defence system kicks in. This allowed me to critically think about the process and how it affects Emily’ s body.  Also, I liked how you used characters that I would remember, such as representing the T helper cells as the police station who sends out the B cells, that develop into plasma cells (antibodies), which are the police officers, to watch out for the beta lactam antigen, the Villain.  I found this way of looking at it helped me better visualize and understand the different roles of the T, B cells, IgE and the chemical mediators’ roles; it was also helpful in understanding why certain symptoms occurred. Overall, I enjoyed the story line of Cillin in a realistic scenario and felt that it allowed me to critically think about what I would do if Emily were my patient.

If I were to make one change, I would be interested in another scenario about a patient having an anaphylaxis reaction to a drug as treatment and monitoring would be similar but also different. Consider adding onto the story line. For example, “instead of Emily being exposed to amoxillin twice, she reacts right away within the 15 minutes after receiving the first IV dose. This would be an example of anaphylaxis reaction”. With anaphylaxis you would want to be more cautious of a biphasic anaphylaxis occurring after the initial event so you would want to monitor just like a drug allergy reaction. Epinephrine and diphenhydramine are both antihistamines but are usually used with different severity reaction. I believe epinephrine would be the first drug to treat an anaphylactic reaction as it is more effective and fast acting especially when airway is at risk, while diphenhydramine can help with the hives and itchiness. Other medications also may be considered like a puffer (albuterol) or IV fluids after to assist with other symptoms. I feel like staff members and patients need to be aware of the risk of anaphylaxis as it is common in the hospital with different medications, like CT contrast. Becoming familiar with our nursing role and the protocol of epinephrine is important in case of an anaphylaxis reaction occurring. It is also important to be aware whether a patient has had an anaphylactic reaction in the past so that when they go for testing to confirm an allergy, they don’t put themselves at risk for having another one. Allergen skin tests should be done with caution or avoided by individuals with past anaphylactic reactions. A blood test for IgE levels may be a safer route for these individuals.

I feel like learning more about the pathophysiology and treatment plan for a drug allergic reaction will be beneficial and helpful in my future practice.  Knowing that drug allergic reactions can take time, what symptoms to look out for and being familiar with the treatments can save our patient’s life. I have not experienced someone having a drug allergy to a particular medication that involves interventions like diphenhydramine or epinephrine. I have only experienced patients developing side effects to medications such as nausea and vomiting. This story has helped me understand the different stages of a drug allergy reaction and has made it clear that it is important to monitor the patients 15-30 minutes post any medication administration. Even though they may not react the first or second time there is a potential a patient could react a third time. It’s good to know reactions can also depend on how much they are exposed to and over how long. It also shows the importance of identifying the patient’s allergies prior to medication administration or at the beginning of a patient’s admission. I feel like penicillin is not used as often as it is a known drug allergy. But it is important to be mindful of the other penicillin family groups as some people may react to the same structure. As nurses we are the ones who often identify allergic interactions with medications that are ordered by the physician. We play a role in ensuring safety and need to always make certain we are checking allergy bands prior to administering any medication in an acute setting. Using the red allergy bands or a medical alert bracelet can help prevent any future reactions. Also, having an idea of the pathophysiology is beneficial as you are aware of the inflammation process and the chemical mediators that cause certain symptoms. This way you can focus your treatment to the specific symptoms the patient is experiencing. A drug allergy reaction could happen at any time and is not always preventable. We nurses can do our part by confirming their known allergies and knowing how to treat a reaction to prevent and minimize negative consequences.  I really enjoyed watching your video. Great job team!