EMS Pharmacology Week 4: Adverse Drug Reactions

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Questions and Answers

What is a characteristic of Type A (augmented) adverse drug reactions (ADRs)?

Approximately 80% of ADRs are classified as this type (correct)

Only occur in neonates

Always result in severe consequences

Are unpredicted and random in nature

Which factor does NOT contribute to the likelihood of developing ADRs?

Personal preference for medication (correct)

Concurrent diseases

Age of the individual

Route of administration

What does the therapeutic index measure?

The balance between a drug's therapeutic effects and toxic effects (correct)

The time taken for a drug to take effect

The overall cost-effectiveness of a drug

The average response time of a drug in different populations

What does LD50 represent in the context of the therapeutic index?

Lethal dose in 50% of the population Signup and view all the answers

What type of reactions are classified as type D reactions?

Withdrawal effects Signup and view all the answers

What is the significance of genetic factors in the context of ADRs?

They may lead to enzyme deficiencies that increase susceptibility Signup and view all the answers

Which of the following is a limitation of the therapeutic index?

It does not account for individual variability in drug responses Signup and view all the answers

Which group is at a higher risk for developing ADRs due to age?

Elderly people and neonates Signup and view all the answers

What characterizes Type B ADRs?

Uncommon and not related to known pharmacological action Signup and view all the answers

Which of the following is a common symptom of an allergic drug reaction?

Rash Signup and view all the answers

What may contribute to Type B ADRs?

Abnormalities in drug metabolism Signup and view all the answers

Which response best describes the occurrence of allergic drug reactions?

They occur following a prior sensitization to the drug Signup and view all the answers

What is a common delayed effect seen with Type D ADRs?

Rebound effect Signup and view all the answers

What type of reaction presents with airway swelling and shock?

Type B ADR Signup and view all the answers

Which statement about Type C ADRs is true?

They are related to cumulative doses over time Signup and view all the answers

What is an adverse drug reaction (ADR)?

An injury resulting from medical intervention related to a drug. Signup and view all the answers

Which classification system describes type B adverse drug reactions?

Bizarre reactions. Signup and view all the answers

Which population is reported to have a higher incidence of adverse drug reactions?

Women, particularly the elderly. Signup and view all the answers

What is one of the key components in the identification process of adverse drug reactions?

Pattern recognition. Signup and view all the answers

What is the main focus of population pharmacokinetics?

The variability of drug concentration and effects in individuals. Signup and view all the answers

Which drug reaction category is NOT recognized in the classification of ADRs?

Type E (exaggerated). Signup and view all the answers

What is a common risk factor for developing an adverse drug reaction?

Age and sex. Signup and view all the answers

Which of the following best describes a teratogenic drug?

A drug that causes developmental abnormalities in a fetus. Signup and view all the answers

What does a teratogenic substance cause in a foetus?

Permanent physical disorder Signup and view all the answers

Which statement best describes mutagenesis?

It involves the modification of DNA. Signup and view all the answers

What is a significant concern regarding medication interactions?

Incompatibility during administration Signup and view all the answers

When assessing risk versus benefit of a drug, what is critical?

The acceptable risk of a drug compared to its therapeutic benefit Signup and view all the answers

Which of the following factors can affect the risk versus benefit analysis of a drug?

The route of administration Signup and view all the answers

What are most adverse drug reactions (ADRs) related to?

Dose/concentration of the drug Signup and view all the answers

Which of the following is NOT one of the ‘7 rights’ of drug administration?

Right environment Signup and view all the answers

What can a carcinogen do to the body's cells?

Cause abnormal cell growth Signup and view all the answers

What is the first step in ensuring safe medication administration?

Administer the right drug Signup and view all the answers

Which of the following is an important action before using an unfamiliar drug?

Take more time and double check Signup and view all the answers

What does the phrase 'If in doubt, throw it out' imply in medication administration?

Do not administer if unsure of contents Signup and view all the answers

What should be confirmed when administering a drug?

The clinical guidelines Signup and view all the answers

Why is it important to check the time and duration of medication administration?

To identify if it's a one-off dose or requires frequent repetitions Signup and view all the answers

Which of these drugs should be reviewed for the upcoming medication quiz?

Syntometrine Signup and view all the answers

What is the significance of frequent smaller doses?

They help maintain steady drug concentrations in circulation Signup and view all the answers

Which aspect is NOT part of the right medication administration principles?

Right flavor Signup and view all the answers

Study Notes

EMS Pharmacology Week 4, Lecture 2: Adverse Drug Reactions

Adverse drug reactions (ADRs) are injuries resulting from medical intervention related to a drug.
ADRs may not be directly caused by the drug itself, but rather due to errors in administration (wrong drug, dose, route, situation).
Learning objectives include describing different types of adverse drug reactions, understanding the classification system, defining allergic reactions, identifying risk factors for adverse drug reactions, defining the clinical implications of drug interactions, and differentiating between carcinogenic, mutagenic, and teratogenic drugs.

Phases of Drug Discovery

Drug discovery involves several phases, taking years.
100 drug projects typically yield 20 compounds.
Preclinical development (2-5 years) includes target selection, lead optimization, pharmacological profiling, and synthesis scale-up.
Clinical development (5-7 years) includes trials testing drug efficacy, dosage, toxicity in healthy volunteers and assess reactions in patients.
Regulatory approval involves the submission of data for review by agencies.
Post-marketing surveillance monitors potential risks associated with the drug after approval.

Population Pharmacokinetics and Pharmacodynamics

Population pharmacokinetics studies how drug concentrations and effects vary among individuals.
The same dose can have widely different effects on different people.

Adverse Drug Reactions

The process of identifying ADRs must include timing, pattern recognition, and investigations.
There are additional resources (articles and videos) on ADRs in clinical trials, including a case study concerning a drug trial disaster.

Classification of ADRs

ADRs occur in people of all ages but are more common in women and the elderly.
Type A (augmented) ADRs are common, predictable, and typically mild.
Type B (bizarre) ADRs are less common, unpredictable, and can be severe.
Other types include Type C (chronic) and Type D (delayed).

Risk Factors for Developing ADRs

Age (elderly and neonates have higher risk), gender (women have a higher risk), concurrent diseases, genetic factors, and history of prior drug reactions can increase susceptibility to ADRs.
Chemical characteristics and route of administration, dose, and duration/frequency of therapy are also important.

Type A ADRs

Account for roughly 80% of ADRs.
Predominantly predictable and linked to the drug's primary pharmacological action (e.g., anticoagulant bleeding).
Usually mild, with high morbidity and low mortality.
Can usually be reproduced in animal studies.
Contributing factors include drug dose, formulation variability, pharmacokinetic variations, pharmacodynamic variations, and drug interactions.

Therapeutic Index

The therapeutic index is the ratio of the maximum non-toxic dose to the minimum effective dose.
It's a measure of a drug's safety margin.
Variability between individuals can make interpreting the therapeutic index challenging since the same dose can have different effects.
Additional measures like clinical trial data are needed to evaluate true benefit/risk ratios.

Type B ADRs

Represent approximately 20% of ADRs.
Unpredictable
Not related to the drug's primary pharmacological action.
Often associated with high morbidity and mortality.
Usually not reproducible in animal studies.
Contributing factors can be pharmaceutical variability, receptor abnormalities, unmasking of a biological deficiency, abnormalities in drug metabolism, or drug allergy.

Allergic Drug Reactions

A drug allergy or hypersensitivity is a type B ADR.
Common drugs involved are penicillin, streptomycin, and radiologic contrast media.
Allergic reactions typically follow an antibody response in the patient.
Reactions are often characterized by a rapid onset, occurrence in a small number of people, a previous exposure to a chemically similar drug, rapid development after re-exposure, and clinical manifestations of an allergic response.
Severe reactions can be life-threatening and involve anaphylaxis, airway swelling, difficulty breathing, hypotension, and shock.

Type C (Chronic) ADRs

Uncommon ADRs arising from cumulative, long-term drug use.
Can include drug tolerance/physical dependence, tardive dyskinesia, or rebound effects.

Type D (Delayed) ADRs

Uncommon (approximately 20%)
Appear some time after drug use
Usually dose-related
May be acceptable if benefit outweighs the risk (e.g., infertility vs. cancer treatment).

Teratogenic Drugs and Chemicals

Teratogens cause physical or functional disorders in a fetus (but not to the mother).
Susceptibility depends on the stage of fetal development and the duration of exposure.

Mutagenic and Carcinogenic Drugs

Mutagenic drugs modify DNA and cause mutations, potentially leading to cancer.
Carcinogens damage the genome and disrupt cellular metabolic processes, potentially leading to the formation of abnormal cells, such as cancer cells.

Medication Interactions

Medication interactions involve an undesirable effect from combined use of medications.
Incompatibility of medications during administration is a major concern leading to altered effects on other drugs.

Limiting Adverse Drug Reactions

Risk—benefit assessment is crucial for deciding whether to use a drug, despite potential adverse effects.
Dose/concentration plays a significant role in determining adverse reactions, and many are therefore preventable.
The "7 rights" of drug administration include considering the right patient, medication, dose, route of administration, time, and documentation. The 7th right is the right for the patient to refuse.
Clinicians should meticulously check and verify information on potentially unfamiliar drugs.

Medication Review for Next Week

The next week's medication quiz requires review of Misoprostol, Syntometrine, and Epinephrine 1:1,000.

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Description

This quiz covers the critical topic of Adverse Drug Reactions (ADRs) in EMS pharmacology. Learn to identify types of ADRs, understand their classification, and recognize risk factors and clinical implications. Test your knowledge on drug interactions and specific drug characteristics such as carcinogenic, mutagenic, and teratogenic effects.