Chapter 5: Adverse Drug Reactions

Question 1

adverse drug reactions

Answer 1

Defined by the World Heath Organization:​
Any noxious, unintended, and undesired effect that occurs at normal drug doses​

Excludes excessive dosages​

Can range from annoying to life-threatening​

Most common in the elderly and the very young​

Risk increased by severe illness

Question 2

ADR stats

Answer 2

AHRQ (agency for healthcare research quality) (2018): Dramatic rise in adverse drug reactions ​

Adverse drug reactions: More than 1,100,000 outpatients sought emergency treatment for adverse drug reactions ​

Hospitalized patients: over 1,735,500 experienced adverse outcomes as a result of drug reactions and medical errors​
Of these 1,735,500, more than 53,800 died

Question 3

side effect

Answer 3

A nearly unavoidable secondary drug effect produced at therapeutic doses​

May develop soon after drug is initiated or not until drug has been taken for weeks or months

Question 4

toxicity

Answer 4

Formal definition: Adverse drug reaction caused by excessive dosing​

May occur even with normal dosing​
Neutropenia (risk for infection) and anticancer medications​

detrimental physiologic effect

Question 5

allergic reactions

Answer 5

Immune response​

Determined primarily by the degree of sensitization of the immune system rather than by drug dosage​

Patient’s sensitivity to a drug can change over time​

Very few drugs cause severe allergic reactions​
Penicillins are the most common​
Allergies may also be induced by sulfonamides (diuretics, antibiotics, and oral hypoglycemic agents)​

Question 6

idiosyncratic effect

Answer 6

An uncommon drug response resulting from a genetic predisposition​

Succinylcholine-induced paralysis​
Usually brief but may last for hours in genetically predisposed patients​

Question 7

paradoxical effect

Answer 7

The opposite of the intended drug response​

For example, when using benzodiazepines for sedation to treat insomnia, excitement may occur instead (especially in children and older adults)

Question 8

iatrogenic disease

Answer 8

Iatrogenic: Literally, “a disease produced by a physician”; also used to refer to a disease produced by drugs (e.g., drugs for antipsychotic disorders can cause Parkinson-like symptoms)​

Sometimes also called drug-induced disease​

Essentially identical to naturally occurring pathology

Question 9

physical dependence

Answer 9

Develops during long-term use of certain drugs (opioids, alcohol, barbiturates, and amphetamines)​

A state in which the body has adapted to drug exposure in such a way that an abstinence syndrome will result if drug use is discontinued​

Important to warn patients against abrupt discontinuation of any medication without first consulting a knowledgeable health professional

Question 10

carcinogenic effect

Answer 10

Only a few therapeutic agents are carcinogenic​

Several drugs used to treat cancer are among those with the greatest carcinogenic potential​

Evaluating drugs is difficult; it may take decades for evidence of carcinogenesis to appear after exposure​

An example of this is diethylstilbestrol (DES)

Question 11

tetratogenic effect

Answer 11

drug-induced birth defect

Question 12

organ-specific toxicity

Answer 12

Many drugs are toxic to specific organs, such as the liver or heart​

Common examples include:​

Kidneys: Amphotericin B (antifungal)​

Heart: Doxorubicin (anticancer)​

Lungs: Amiodarone (antidysrhythmic)​

Inner ear: Aminoglycoside (antibiotic)​

Question 13

hepatotoxic drugs

Answer 13

Leading cause of liver failure in the United States​

More than 50 drugs are known to be hepatotoxic​

As some drugs undergo metabolism, they are converted to toxic products that can injure liver cells​

Combining hepatotoxic drugs may increase the risk for liver damage (e.g., acetaminophen and alcohol)​

Monitor aspartate aminotransferase (AST) and alanine aminotransferase (ALT) for liver injury​

Watch for signs of liver injury; educate patients about jaundice, dark urine, light-colored stools, nausea, vomiting, malaise, abdominal discomfort, and loss of appetite

Question 14

QT interval drugs

Answer 14

QT interval: Measure of the time required for the ventricles to repolarize after each contraction​

QT drugs: Drugs that prolong the QT interval on electrocardiogram (ECG)​

Creates serious risk of life-threatening dysrhythmias​

Examples: Torsade’s de pointes, ventricular fibrillation

Question 15

minimize risk of QT interval drugs

Answer 15

Most patients are at higher risk, including women, older adults, and patients with bradycardia, congestive heart failure (CHF), congenital QT prolongation, low potassium, and low magnesium ​

Do not use two QT drugs concurrently

Question 16

identifying ADRs

Answer 16

Can be very difficult to determine whether a specific drug is responsible for an observed adverse event​

Other factors to consider:​ Underlying illness​ and Other drugs

Did symptoms appear shortly after the drug was first used?​

Did symptoms abate when the drug was discontinued?​

Did symptoms reappear when the drug was reinstituted?​

Is the illness itself sufficient to explain the event?​

Are other drugs in the regimen sufficient to explain the event?

Question 17

ADR to new drugs

Answer 17

Half of all new drugs have serious adverse drug reactions that are not revealed during Phase II and Phase III trials​

Be alert for unusual responses when giving new drugs, because newly released drugs may have as-yet-unreported adverse effects​

Drugs that are suspected of causing a previously unknown adverse effect should be reported to MedWatch, the FDA Medical Products Reporting Program

Question 18

ways to minimize ADRs

Answer 18

Responsibility for reducing ADRs lies with everyone associated with drug production and usage:​
Pharmaceutical industry: Strive to produce the safest medications possible​
Prescriber: Select the least harmful drug; balance potential risks with probable benefits​
Nurse: Evaluate patient for ADRs; educate patients and families about how to minimize harm​
Patients and families: Watch for signs that an ADR may be developing; see medical attention if one appears

The anticipation of ADRs can help to minimize them​

Target the evaluation of the function of any at-risk organs​

Important sites of toxicity:​
Liver: Signs of jaundice; monitor liver function tests​
Kidney: Routine urinalysis and serum creatinine level (periodic creatinine clearance testing)​
Bone marrow: Periodic blood cell counts​

Patients with chronic disorders are especially vulnerable to ADRs

Question 19

medication guides

Answer 19

FDA-approved documents created to educate patients about how to minimize harm from potentially dangerous drugs​

Required when the FDA has determined that (1) patient adherence to directions for drug use is essential for efficacy and (2) patients need to know about potentially serious effects when deciding whether to use a drug

Question 20

boxed warnings

Answer 20

Also known as black box warnings​

Strongest safety warning a drug can carry and still remain on the market​

Purpose of this warning is to alert prescribers to:​
Potentially severe side effects (e.g., life-threatening dysrhythmias, suicidality, major fetal harm) ​
Ways to prevent or reduce harm (e.g., avoiding a teratogenic drug during pregnancy)

Question 21

risk eval and mitigation strategies (REMs)

Answer 21

REMS: A plan to minimize drug-induced harm ​

For example, the REMS for isotretinoin is called iPLEDGE​

Isotretinoin can cause serious birth defects​

iPLEDGE was designed to ensure that those who are pregnant or who may become pregnant will not have access to the drug

Question 22

what is a medication error and who makes them

Answer 22

The risk for error in hospitals is high because each medication order is processed by several people​

The nurse is the last person in this sequence​

Thus, the nurse is the last line of defense against mistakes ​

This places a heavy responsibility on the nurse to ensure patient safety

Question 23

ways to reduce medication errors

Answer 23

Help and encourage patients and their families to be active and informed members of the health care team​

Give health care providers the tools and information they need to prescribe, dispense, and administer drugs as safely as possible​

Institute safety checklists for high-alert drugs​

About 20 drugs cause 80% of medication error–related deaths
Replace handwritten medication orders with a computerized order entry system​

Have a senior clinical pharmacist accompany physicians on rounds​

Do not use error-prone abbreviations​

Perform medication reconciliation ​

Question 24

how to report medication errors

Answer 24

Medication Errors Reporting (MER) program:​

Reporting is confidential​

Reporting can be done by phone, fax, or Internet​

Program encourages all health care providers—including pharmacists, nurses, physicians, and students—to report errors​

https://www.ismp.org/orderforms/reporterrortoismp.asp​

All information is forwarded to the U.S. Food and Drug Administration (FDA), the Institute for Safe Medication Practices (ISMP), and the product manufacturer