Adverse Drug Reactions

Question 1

Adverse Drug Reaction

Answer 1

Any undesirable or unintended effect occuring after administration of a medical product
Two types
-Pharmacological (85-90%)
-Idiosyncratic (unpredictable)

Every drug has the potential to cause harm
Unintended
Unpredictable, but some MAY be predictable

Question 2

Hypersensitivity Reactions

Answer 2

Type 1: Immune-mediated reactions (immunoglobulin E (IgE) mediated, immediate type hypersensitivity)

Type II: antibody-dependent reaction

Type III: Immune complex hypersensitivity

Type IV: cell-mediated or delayed type hypersensitivity

Question 3

Type I Allergic Response

Answer 3

Anaphylactic reaction
Immediate response
Previously sensitized person
Reaction mediated by IgE antibodies on mast cells
May be fatal if not treated immediately

Question 4

Type II Allergic Response

Answer 4

Cytotoxic reaction
Sometimes called autoimmune response
Hemolytic anemia, thrombocytopenia, drug-induced lupus
Improvement with removal of drug

Question 5

Type III Allergic Response

Answer 5

Arthus reaction or immune complex reaction
Also called “serum sickness”
Angioedema, arthralgia, fever, swollen lymph nodes, and splenomegaly
Occurs 1-3 weeks after drug exposure

Question 6

Type IV Allergic Response

Answer 6

Cell-mediated, delayed hypersensitivity

Common skin reaction that occurs 24 to 48 hours after drug contact with skin

Question 7

Types of ADRs

Answer 7

Type A: pharmacological reactions
Type B: Idosyncratic reactions
Type C: result from chronic medication use
Type D: delayed reactions
Type E: Drug-drug interactions
Type F: treatment failures

Question 8

Time-Related ADRs

Answer 8

Rapid reactions
First-dose reactions
Early reactions
Intermediate reactions
Late reactions
Delayed reactions

Question 9

Dose-related ADRs

Answer 9

Excessive dose

Not adjusting dose for age or organ dysfunction (kidney , liver)

Question 10

Severity of ADRs

Answer 10

Serious ADRs cause hospitalization or death
Moderate reactions
Mild reactions

Question 11

Predicting ADRs

Answer 11

Genetic factors
Age (young and old)
Body Mass
-Adult dosing is based on average weight of 150lbs
-Lean or obese patients
-Children dosed in mg per kg (mg/kg)
-Morbidly obese patients need dosing adjustment of some medications due to distribution
Gender
-Women tend to be smaller
-Different fat distribution
-Pregnancy changes
Environment
-Drugs affecting mood and behavior
-Physical environment: low oxygen (o2), temperature
Time of administration
-Timing with food
-Biorhythms may affect drug absorption and excretion
Pathological state
-Pain intensifies the need for opioids; anxiety may produce resistance to antianxiety drugs
-Renal or hepatic dysfunction
Psychological factors
-Cultural or faith based attitudes toward drugs

Question 12

Drugs during Pregnancy

Answer 12

Teratogens
Exposure during first trimester
Some drugs are known to cause teratogenesis
-Category X
-Category C
Exposure later in pregnancy
-Fetal effects
-Abortificants (induces abortion)

Question 13

Pregnancy Labeling Change

Answer 13

After July 1, 2015, all new drugs have new pregnancy labeling

Question 14

ADRs Caused by Drug Interactions

Answer 14

Many identified drug reactions will not have clinical significance for the individual patient

A small number will have significant clinical consequence

The NP should work with a pharmacist to identify significant interactions

Question 15

Responding to ADRs

Answer 15

Discontinue drug
Continue if medically necessary
Rechallenge to confirm drug caused ADR
Naranjo ADR Probability Scale

Question 16

ADR Reporting

Answer 16

Post-marketing surveillance
US FDA Adverse Event Reporting System
MedWatch
Vaccine Adverse Events Reporting System