NAPLEX Question of the Week: Sickle Cell Scenario

This week's question focuses on sickle cell disease treatment.
NAPLEX Question of the Week: Sickle Cell Scenario
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CH is a 33 yo female who presents to the ED with pain radiating her entire body including chest pain, having intermittent fevers, and feeling constant fatigue throughout the day. CH reports having severe pain over the past few months that did not respond well to 6-7 tablets of Advil a day. Upon inspection of records, at her previous primary care visit a HgB S lab was ordered which was positive. She takes OTC Tylenol and Advil for pain PRN and was awaiting appointment with a hematologist for complete evaluation (has not received any opioids). Her labs and vitals this morning are as follows: 

Height 5’2’’ 

Weight 56 kg 

Allergies: Sulfa (rash)

Na+ 143 meq/L (135-145 meq/L)

K+:  4 meq/L (3.5-5 meq/L)

SCr 0.7 mg/dL (0.6-1.2 meq/L)

Glu 99 mg/dL (70-110 mg/dL)

Hgb 6.1 (12.1-15.1g/L)

WBC 13.4 K (4.5-10 X109/L)

BP 107/68 mm Hg

Temp 101.2

Pain score 8 – 10 

The ED physician wishes to treat CH for her Sickle Cell anemia with concurrent vaso-occlusive pain crisis including acute chest pain. What medications would be reasonable for CH’s initial treatment? (Select all that apply)

A. Rocephin 

B. Droxia

C. Jadenu

D. Morphine

E. Fentanyl

 

 

 

 

 

 

 

 

Answer choices A, B, and D are correct 

Brand names covered: Rocephin (ceftriaxone), Droxia (hydroxyurea), Jadenu (deferasirox)  

Answers with rationale: 

Sickle cell anemia is a highly inherited disorder in the US and heavily affects the African American population. Sickle cell formation is caused by an abnormal beta hemoglobin subunit called hemoglobin S. This disease is inherited, and the most common type inherited is homozygous hemoglobin SS, presenting full symptoms and characteristics of Sickle cell anemia. Red blood cells with the sickled trait would be deformed in shape, leading to occlusion of vessels from stuck cells and trigger formation of more sickled cells. Complications from sickle cell anemia include vaso-occlusive crisis, acute chest syndrome, infections, and thrombus formation.  

Answer choice A is correct as the patient is febrile, has an elevated WBC count and chest pain. Due to the increase in bone marrow turnover of sickled cells and altered complement activation alongside possible functional asplenia, the patient is in an immunocompromised state. Patients with functional asplenia are at risk of infections with encapsulated bacteria such as Streptococcus pneumoniae and Haemophilus influenzae, thus empiric coverage with ceftriaxone is sufficient. If not treated, infections may cause sepsis and lead to poor patient outcomes.  

Answer choice B is correct as hydroxyurea is one of the mainstay treatments for sickle cell anemia. Hydroxyurea is a chemotherapeutic agent which the mechanism to treat sickle cell anemia is to promote the formation of non-sickle cell hemoglobin chains (HgF) thus less resources are used to make more sickled cells. Hydroxyurea can help decrease the amount of pain crises, however since the drug is a chemotherapeutic, the main side effect limiting use is myelosuppression. Monitoring the CBC every 1 – 2 months is necessary to titrate doses to prevent blood counts from going too low.  

Answer choice C is incorrect as deferasirox is indicated when the patient is exhibiting evidence of iron overload from chronic infusion therapy. The patient had been recently diagnosed with sickle cell anemia, thus the likelihood of iron overload is low. If the patient exhibits symptoms of iron overload (lethargy, fatigue, etc.) and iron studies show elevated levels, deferasirox may be considered if on chronic blood transfusions. 

Answer choice D is correct as the patient is exhibiting intense pain due to her high scores which are refractory to other pain management options such as ibuprofen. Caution is needed since the patient is opioid naïve.  A scheduled or intermittent pain regimen may be started, followed by titration if necessary. Naloxone, an opioid reversal agent, should be available for the patient in the case of opioid overdose. 

Answer choice E is incorrect as fentanyl should only be given in patients who have demonstrated tolerance to chronic opioid use of first-line agents, such as an equivalent of 60mg/daily of morphine. While the dosage form was not specified, transdermal fentanyl even in an opioid tolerant patient would not be used for acute pain as the onset is slow. It is only indicated for chronic stable pain when given transdermally.

Always remember to dispose of transdermal fentanyl by folding the patch together and flushing down the toilet to prevent small children from getting the product unintentionally overdosing as absorption from used patches has occurred: https://www.fda.gov/consumers/consumer-updates/accidental-exposures-fentanyl-patches-continue-be-deadly-children

References: 

American Society of Hematology Guidelines on Sickle Cell Disease  

NAPLEX Competency Statements: 

1.5 – Signs or symptoms of medical conditions, healthy physiology, etiology of diseases, or pathophysiology 

2.1 – Pharmacology, mechanism of action, or therapeutic class 

2.2 – Commercial availability; prescription or non-prescription status; brand, generic, or biosimilar names; physical descriptions; or how supplied 

3.3 – Medication reconciliation; indication or therapeutic uses; lack of indication; inappropriate indication; duplication of therapy; omissions 

3.11 – Evidence-based practice

Shout out to all of the students at ASHP Midyear who are working toward residency training and fellowship program matches. Even got to meet two wonderful students here in Vegas from Rutgers University Ernest Mario School of Pharmacy who were discussing the upcoming NAPLEX.

Dr. B

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