Drug Allergies and Adverse Drug Reactions

A patient reports that he became light headed and started wheezing, with trouble getting "enough air in" when he was prescribed ampicillin. He has a strep throat infection and the decision is made to start antibiotic therapy today. Which antibiotic therapy would represent a potentially unsafe choice in this patient? Answer A Moxatag B Avelox C Doxycycline D Zithromax E Minocin

A Penicillin is a beta-lactam antibiotic and there are many related compounds in this family, including amoxicillin (Moxatag). It is best to avoid related compounds unless the infection warrants use and the patient can be monitored.

If a patient has a true allergy to penicillin, they may have an allergic reaction to which of the following drugs? (Select ALL that apply.) Answer A Zosyn B Augmentin C Keflex D Primaxin E Zithromax

ABCD All except azithromycin are beta-lactam antibiotics. If the pharmacist sees an allergy to penicillin (or another beta lactam) on the exam, he/she should not choose drugs in the same class. In reality, the cross-reactivity between penicillins and other beta lactams is much lower than previously thought. But the exams are primarily safety-focused and you should not pick an agent that can cross-react. See the course book for rare exceptions to this. Primaxin (cilastin/imipenem)

Which of the following associations is not correct? Answer A Type A reaction - predictable, dose-related (e.g., orthostasis with an alpha-blocker) B Type B reaction - unpredictable (e.g., itching with opioids) C Type I reaction - occurs within 15-30 min, immune-mediated (e.g., anaphylaxis) D Type II - pseudoallergic reaction (e.g., red man syndrome with rapid vancomycin infusion) E Type IV reaction - delayed hypersensitivity occuring 48 hours to weeks after exposure

D An example of a Type II reaction is hemolytic anemia. Pseudoallergic reactions would fall into type B reactions (unpredictable, but may be more likely under certain circumstances-in this case rapid infusion), but do not fall into types I-IV, which apply to immune-mediated allergic responses.

A patient developed hives after using Bactrim. Choose a medication that is not contraindicated with this type of allergy: Answer A Celecoxib B Sulfapyridine C Zonisamide D Dapsone E Sulfasalazine

D Sulfa allergies are most common with sulfamethoxazole, and the related compounds sulfapyridine, sulfadiazine, and sulfisoxasole. Celecoxib and zonisamide are contraindicated with this allergy, although a cross-reaction is less likely.

Epinephrine injection now comes in a "talking" injection device that can help guide patients how to administer the injection. What is the name of this device? Answer A Evzio B Copaxone C Lemtrada D Arixtra E Auvi-Q

E Auvi-Q is a newer device that is easy to use; however, the EpiPen is also simple to use.

CD developed hives and got a swollen face from using sulfamethoxazole. CD should avoid the use of which of these drugs? (Select ALL that apply.) Answer A Sulfasalazine B Furosemide C Zonisamide D Celecoxib E Morphine sulfate

ABCD Commonly called a "sulfa" allergy, reactions are most likely due to the sulfonamide component in Bactrim (sulfamethoxazole). If there was a reaction to this drug the patient should avoid using sulfasalazine. Regarding the other formulations: the likelihood of a reaction with zonisamide or celecoxib is lower, but they are contraindicated with a sulfa allergy; furosemide and the the loop diuretics carry a warning for use in patients with sulfa allergy. The safest choice for all of these is to avoid them altogether, especially on the exam. Sulfate is not the same as sulfonamide; morphine sulfate can be used in this patient.

CK lives in southern California. She is fair-skinned and burns easily. CK recently had a urinary tract infection and received a prescription for sulfamethoxazole/trimethoprim (Bactrim). CK was not told that she would burn even more easily when using this medication. Which of the following medications also cause photosensitivity? (Select ALL that apply.) Answer A Tetracyclines B Tacrolimus C Thiazide diuretics D Quinolone antibiotics E Metronidazole

ABCD Many drugs can cause photosensitivity, which requires limiting sun exposure and using sunscreens that block both UVA (causes aging, skin cancer) and UVB (causes sunburn). Sunscreens that cover both UVA and UVB are labeled broad-spectrum.

A community pharmacist is reviewing a new prescription for azithromycin for a young man. The pharmacist asks about his allergies and he says the only allergy he has is to erythromycin. Which of the following questions should the pharmacist ask the patient? (Select ALL that apply.) Answer A What happened when you took erythromycin? Was it a mild rash, a severe rash with blisters, trouble breathing, upset stomach or nausea? B Did you take erythromycin for more than 72 hours to confirm that is was a "true" allergy? C Have you ever used azithromycin (Zithromax) or clarithromycin (Biaxin)? If so, what happened when you took these? D Are any of your family members allergic to azithromycin? E When did your reaction to erythromycin occur? About how old were you?

ACE Erythromycin commonly causes cramping and stomach upset. This is commonly reported as an allergy, and it should be listed it as an intolerance and the reaction (since it bothered the patient and, if possible, the drug should be avoided), but this is not an allergy and should not prevent drugs in the same class from being used.

A 19 month old male is diagnosed with his 3rd case of acute otitis media in the past 14 months. He has received amoxicillin twice before. The second time he developed a red rash on his torso and arms. Which of the following would be recommended for use in this patient for the current illness? Answer A Augmentin suspension B Cefuroxime suspension C MInocycline suspension D Doxycycline suspension E Levofloxacin suspension

B Augmentin contains amoxicillin, so it would not be appropriate with the history of rash. Tetracyclines and levofloxacin have appropriate spectrum of activity, but are not appropriate for the patient's age. A second or third generation cephalosporin is recommended if the penicillin allergy was mild (not life-threatening). This is a rare exception, as generally on the exam, when an allergy to one beta-lactam is present all beta-lactams should be avoided.

JB is a 7 year old who has a severe allergy to peanuts that he and his mother carries an EpiPen. Which of the following medications are in a soy base and must be avoided in patients with a peanut allergy? (Select ALL that apply.) Answer A Albuterol inhaler B Cleviprex C Diprivan D Precedex E Morphine

BC Clevidipine, propofol and progesterone in Prometrium must be avoided in patients with a peanut allergy.

If a patient has a true allergy to eggs, they cannot receive which of the following agents? (Select ALL that apply.) Answer A Advair B Cleviprex C Diprivan D Pneumovax E Flublok

BC Patients with an egg allergy should not receive clevidipine and propofol. Flublok is a recombinant influenza vaccine that contains no eggs

A patient presents to the pharmacy to pick up a refill on his Androgel. This medication requires a MedGuide. Which of the following is not true? Answer A MedGuides are FDA approved patient handouts. B MedGuides are written in non-technical language. C The MedGuide is not considered part of the drug labeling. D The MedGuide must be dispensed with every new prescription. E The MedGuide must be dispensed with every prescription refill.

C

TL is a 27 year old female who is pregnant and has been diagnosed with syphilis. She has an allergy listed to penicillin (hives). The doctor has ordered a penicillin desensitization procedure followed by Bicillin L-A. Which of the following is false regarding penicillin desensitization? Answer A Very small doses of penicillin will be administered, slowly escalating up to therapeutic doses. B The procedure should take place in a setting where emergency care can be provided if anaphylaxis develops. C The penicillin allergy should be removed from the profile after desensitization and the patient can safely receive penicillins in the future. D Desensitization is not recommended if the patient previously had an idiosyncratic reaction such as Stevens-Johnson syndrome or toxic epidermal necrolysis (TEN). E Desensitization allows the use of the first-line treatment option.

C Desensitization is a temporary "fix" that induces tolerance to a drug that would otherwise cause the patient to have an allergic reaction. It does not "cure" a penicillin allergy and if the patient were to need penicillin again in the future, desensitization would need to be repeated. For this reason, the allergy should not be removed from the profile.

RH is a 71 year old female who has a life-threatening allergy to aspirin. She takes ticlopidine 250 mg BID after a stroke 3 years prior. She is at her routine clinic visit and as the nurse applies the blood pressure cuff, she notices that the patient has small red and purple pinpoint spots on her skin and some larger bruises on her hand and upper arm, where she states she had bumped them on a doorway when she lost her balance a few days ago. Upon questioning, she reports no recent fever or other systemic symptoms. Which of the following is consistent with this presentation? Answer A A photosensitivity reaction B Drug Reaction with Eosinophilia and Systemic Symptoms C Stevens-Johnson Syndrome D Toxic epidermal necrolysis E Thrombotic thrombocytopenic purpura

E Pinpoint bruises (petechiae) and larger bruises (purpura) are signs that she may have developed thrombotic thrombocytopenic purpura (TTP), for which ticlopidine carries a boxed warning. This ADR has also been reported with clopidogrel (although with lower freuqency).