Adverse Reactions Flashcards
Define Adverse drug reaction (ADR)
- Any harmful change which is suspected to be due to a drug (administered at normal dose)
- requires treatment, decrease in dose, or indicates caution for future use of the same drug
Define Adverse drug event (ADE)
Unexpected medical occurrence resulting from medical intervention related to a drug.
What are the common causes of ADRs?
Hint: Adverse reaction gOT (COT) me FAT
C - combining medication with alcohol.
O - overdosing
T - taking other drugs or preparations that interact with the medication.
F - failure to take correct doses at the correct time.
A - allergies to chemical components of the medication.
T - taking a medication that was prescribed for someone else.
Patient-related factors affecting ADRs
Hint: TAP that Patient
T - total number of medications.
A - age (children, elderly, pregnancy, breast feeding)
P - previous adverse reactions.
Drug-related factors affecting ADRs
Hint: DIP the Drug
D - dose
I - inherent toxicity of the agent
P -pharmacodynamic /pharmacokinetic properties
Classification of ADRs depending on ONSET OF EVENT
- Acute = < 60 mins
- Sub-acute = 1 - 24 hrs
- Latent = > 2 days
Classification of ADRs depending on SEVERITY (4)
- Minor ADRs
- Moderate ADRs
- Severe ADRs
- Lethal ADRs
Explain MINOR ADRs (severity)
No therapy, antidote or prolongation of hospitalization is required.
Explain MODERATE ADRs (severity)
Requires change in drug therapy, specific treatment or prolongs hospital stay by at least 1 day.
Explain SEVERE ADRs (severity)
Potentially life threatening, causes permanent damage or requires intensive medical treatment.
Explain LETHAL ADRs (severity)
Directly or indirectly contributes to death of the patient.
Classification of ADRs depending on TYPE OF REACTION
Hint: Alphabet = ABCDEF
- Type A = Augmented
- Type B = Bizarre
- Type C = Chronic / Chemical
- Type D = Delayed
- Type E = Exit / End of treatment
- Type F - Failure of therapy
Discuss Type A (Augmented) reactions
- Adverse reactions known to occur from the pharmacology of the drug, and are dose-related.
- Hardly fatal and relatively common.
Give examples of Type A (Augmented) reactions.
- Hypoglycemia due to insulin injection.
- Hemorrhage due to anticoagulants.
Discuss Type B (Bizarre) reactions
- Adverse reactions that occur unpredictably.
- Often have a high rate of morbidity and mortality.
- Uncommon
Give examples of Type B (Bizarre) reactions.
- Anaphylaxis due to penicillin.
- Skin rashes due to antibiotics.
Discuss Type C (Chronic/Chemical) reactions
Adverse reactions that only occur during prolonged treatment and not with single doses.
Give examples of Type C (Chronic/Chemical) reactions.
- Dyskinesia (uncontrolled, involuntary movement) caused by Levodopa use in treatment of Parkinson’s disease.
- Colonic dysfunction due to laxatives.
Discuss Type D (Delayed) reactions
- Adverse reactions that occur remote from treatment.
- either in the children of treated patients, or in patients themselves years after treatment.
Give examples for Type D (Delayed) reactions.
- Carcinogenesis = short-term exposure at a critical time.
- Teratogenesis = process by which congenital malformations are produced in an embryo or fetus.
Discuss Type E (Exit/End of treatment) reactions.
- Adverse reactions that occur when a drug is stopped, especially when it is stopped suddenly
- withdrawal reactions
Give examples for Type E (Exit/End of treatment) reactions.
- Phenytoin withdrawal causes seizures.
- Steroid withdrawal causes acute adrenal insufficiency.
Discuss Type F (Failure of therapy) reactions.
Adverse reactions that occur when drug undesirably increases or decreases in efficacy
Give examples of Type F (Failure of therapy) reactions.
- Decreased clearance of a drug by dialysis
- Decreased effect of antibiotics due to resistance.
Define side effects of drug
Unwanted but often unavoidable effects that occur at therapeutic dose.
-
Give examples of side effects of drugs
- Atropine = dryness of mouth.
- Codeine = constipation
Toxic effects can be _____ or _____
Predictable or Unpredictable
Define Predictable toxic effects
Dose dependent adverse effects that are known by pharmacologists.
