Sinsebox- Drug-Induced Heme Disorders - EXAM 1

based off pp

What is aplastic anemia?

disorder with a decrease in RBCs, WBCs, and platelets (pancytopenia)

What drugs can cause aplastic anemia? Which of these drugs has a BOXED warning for causing aplastic anemia?

• phenytoin

• carbamazepine- BOXED WARNING

• phenobarbital

• cytotoxic chemo and radiation therapy

(Think: PC, PC like a computer)

What is the management/treatment for aplastic anemia?

• remove causative drug

• antimicrobial therapy

• transfusions

• allogenic hematopoietic stem cell transplantation

• immunosuppressive therapy

What is hemolytic anemia?

disorder with premature destruction of RBCs (hemolysis)

__________ test is the best way to diagnose drug-induced hemolytic anemia.

Coombs

Most common cause of hemolytic anemia is _______________.

G6PDD

What are some drugs that cause hemolytic anemia? Which one is most common?

• piperacillin- most common

• phenobarbital

• phenytoin

• nitrofurantoin

• quinidine

• hydroxychloroquine

(think: the 3P’s)

What drugs can cause drug-induced megaloblastic anemia?

• methotrexate

• 5-fluouracil (5-Fu)

• azathioprine

• hydroxyurea

• metformin

• phenytoin

• phenobarbital

Which of the following drug-induced hematologic disorders has a larger red blood cells or MCV?

a. aplastic anemia

b. hemolytic anemia

c. megaloblastic anemia

d. all of the above

c

A deficiency in what 2 vitamins can cause megaloblastic anemia?

folate or b-12

Drugs that have an effect on DNA synthesis most likely result in what kind of anemia?

a. pernicious anemia

b. hemolytic anemia

c. aplastic anemia

d. megaloblastic anemia

d

PRACTICE:

Piperacillin is the most common cause of which drug-induced hematologic disorder?

a. aplastic anemia

b. hemolytic anemia

c. megaloblastic anemia

d. all of the above

b

PRACTICE:

Which of the following is a characteristic of aplastic anemia?

a. G6PD deficiency

b. pancytopenia

c. vitamin b-12 deficiency

d. none of the above

b

PRACTICE:

Methotrexate is a common cause of which hematologic disorder?

a. aplastic anemia

b. hemolytic anemia

c. megaloblastic anemia

d. all of the above

c

What is agranulocytosis? ANC is less than what value?

• disorder with a reduction in the number of NEUTROPHILS

• absolute neutrophil count (ANC) < 500 cells/mm3

Neutropenia is <______cells/uL

1000

WHAT IS THE EQUATION FOR CALCULATING ANC?

(must memorize)

ANC = WBC x (% neutrophils/ 100)

OR

ANC = WBC x (% segs + % bands/ 100)

PRACTICE:

A patient has a WBC of 11.1 and 64% are neutrophils. Calculate ANC and determine if this patient has neutropenia.

ANC= 11.1 x (64/100)

ANC= 7.1 k/uL aka 7,104 cell/uL

THIS PATIENT DOES NOT HAVE NEUTROPENIA BC THEY HAVE 7,104 cells/uL and to have neutropenia you have to have <1000 cells/uL

What drugs cause agranulocytosis? Which drug has a boxed warning for agranulocytosis?

• clozapine

• carbamazepine- BOXED WARNING

• hydroxyurea

What drug has a REMS program because of the risk of neutropenia?

Clozapine

What is the treatment/management for drug-induced agranulocytosis?

• remove offending agents

• colony stimulating factors (CSF)

• antimicrobial therapy

PRACTICE:

A patient is taking clozapine and is at the clinic for a routine visit. Today’s labs include WBC= 4,300 cells/uL with 28% segs and 2% bands. Calculate this patient’s ANC and determine if this patient can refill their clozapine.

ANC = 4,300 (30/100)

ANC = 1,290 cells/mm3

This patient does NOT have neutropenia, so they can refill their clozapine.

What is thrombocytopenia?

disorder with a decreased platelet count

Thrombocytopenia is a platelet count <___________ cells/uL OR greater than ____% reduction from baseline.

Thrombocytopenia is a platelet count <100,000 cells/uL OR greater than 50% reduction from baseline.

What drugs can cause thrombocytopenia?

• HEPARIN

• carbamazepine

• quinidine

• vancomycin

• rifampin

• ibuprofen

What drug causes significant reduction in platelet count with a paradoxical increased risk for clotting? What scoring system is used to evaluate the probability of HIT?

• HEPARIN INDUCED THROMBOCYTOPENIA (HIT)

• 4T scoring system

If HIT occurs heparin must be discontinued and what other anticoagulants can be used in replacement?

• argatroban

• bivalirudin

• danaparoid

• fondaparinux

• DOAC (rivaroxaban and apixaban)

PRACTICE:

Colony stimulating factors, such as filgrastim, can be used in managing which of the following drug-induced hematologic disorders?

a. hemolytic anemia

b. agranulocytosis

c. thrombocytopenia

d. leukocytosis

b

PRACTICE:

Which of the following defines thrombocytopenia?

a. platelets <500 cells/uL

b. ANC <500 cells/uL

c. platelets <100,000 cells/uL

d. ANC <100,000 cells/uL

c

PRACTICE:

Which of the following drugs can be used in tx of HIT? Select all that apply

a. rivaroxaban

b. argatroban

c. enoxaparin

d. protamine

a, b

PRACTICE:

In which of the following is phenytoin NOT a cause of anemia?

a. aplastic anemia

b. hemolytic anemia

c. megaloblastic anemia

d. agranulocytosis

d

PRACTICE:

In which of the following is carbamazepine NOT a cause of anemia?

a. aplastic anemia

b. hemolytic anemia

c. thrombocytopenia

d. agranulocytosis

b

PRACTICE:

In which of the following is phenobarbital NOT a cause of anemia?

a. aplastic anemia

b. hemolytic anemia

c. megaloblastic anemia

d. agranulocytosis

d