Sickle Cell Disease

Question 1

RBC Lifespan

Answer 1

~120 days
-Shaped like donut without a hole

Question 2

SCD: Background

Answer 2

-Affects African American population
-Genetic mutation in genes encoding hemoglobin (hemoglobin S or HgbS)
-Causes RBCs to have a concave “sickle” shape
-Sickled RBCs hemolyze after 10-20 days which causes anemia
-Causes sickle cell crises (vaso-occlusive crisis or acute pain crisis)

Question 3

SCD Develops…

Answer 3

2-3 mo after birth
-bc fetus/infants have fetal hemoglobin (HgBF) which blocks the sickling of RBCs

Question 4

Females with SCD: CI

Answer 4

DONT USE
-Estrogen
-Progestin-only contraceptives

Levonorgestrel IUDs and barrier methods are preferred

Question 5

Spleen

Answer 5

Removes old/damage RBCs
In SCD, spleen shrinks and is fibrotic causing functional asplenia

*susceptible to serious infections =
-Streptococcus pneumoniae
-Haemophilus influenzae
-Neisseria meningitidis

Require immunizations and ppx abx

Question 6

Non-Drug Tx

Answer 6

-Blood transfusions (monthly)
*Goal Hgb no higher than 10 g/dl post-infusion (bc iron overload = need to use chelation therapy if occurs)

-Only cure is bone marrow transplantation (not widely used due to risk and cost)

Question 7

Drug Tx for SCD

Answer 7

-Immunizations
-PPX ABX
-Chelation therapy
-Analgesics

Hydroxyurea is DOC
-Also: L-glutamine, voxelotor, crizanlizumab

AGAV CHIC

Question 8

Immunizations

Answer 8

Childhood
-Haemophilus influenza type B
-PCV15 or PCV20 (Vaxneuvance or Prevnar 20 for pneumococcal)

Asplenia
-Meningococcal (MenACWY) + routine boosters (Menveo, MenQuadfi)
-Meningcoccal B at 10+ yr (Bexsero, Trumenba)
-Pneumococcal vaccines (if never received as child then give 1 of the following at 19+ yr)
*PCV20 x 1
*PCV15 x 1 then PPSV23 8+ wks later

Question 9

PPX ABX

Answer 9

Oral PCN
-Infants who screen + for SCD should be given twice daily PCN and treated until 5 years old
-Continued indefinitely if pt undergoes spleen removal or pneumococcal infection develops despite PCN PPX

Question 10

Chelation Tx

Answer 10

Oral chelating drugs
= Deferasirox (Exjade, Jadenu)
= Deferiprone (Ferriprox)

Question 11

Analgesics

Answer 11

Mild-moderate pain
= fluid, rest, warm compresses, NSAIDs or Tylenol

Severe pain or VOC
= IV opioids or PCA

Question 12

Hydroxyurea (Droxia, Hydrea, Siklos)

Answer 12

Stimulates production of HgbF

Indicated for
-all adults with 1+ mod-sev pain crisis
-peds 9mo-18yr regardless of severity

BBW: myelosuppression, malignancy

Warnings: fetal toxicity, avoid live vaccines

Monitoring: CBC with diff

Contraception REQUIRED for males and females during tx and 6-12 mo after d/c
-Do not breastfeed while on tx

HAZARDOUS drugs (gloves, wash hands)

FOLIC ACID supplementation required to prevent macrocytosis

Response can take 3-6 months

MaM FL CHF

Question 13

L-glutamine (Endari)

Answer 13

AE: constipation, flatulence, nausea, HA, pain, cough

Notes:
-Mix each dose in 8 oz of colt/RT beverage or 4-6 oz of food
-Does not need to be dissolved fully before administration

Question 14

Voxelotor (Oxbryta)

Answer 14

Warning: hypersensitivity
-Lab test interference with Hgb measurement subtype (AFS)

AE: HA, fatigue abdominal pain, diarrhea, nausea

Notes: swallow tablets whole (don’t crush/chew/cut)

SIS = sensitivity, interference (lab), swallow whole

Question 15

Crizanlizumab (Adakveo)

Answer 15

Warnings: infusion-related rxn
-Lab test interference with PLT counts

AE: nausea, arthralgia, fever

CRIZ is a FAN of I and I