Adverse Drug Reactions And Drugs Of Abuse Flashcards
Define adverse drug reactions
Any response to a drug which is noxious, unintended, and occurs at doses used in man for prophylaxis or diagnosis or therapy.
what factors about a person can cause change in the reaction to a drug
What factors can explain reasons ADR
Genetic
Age related
Sex related
Physiological (pregnancy)
Exogenous (drugs)
Disease related
What groups are ADR separated into
Group A and group B ( however it goes all the way to F )
What does a type A ADR stand for
Augmented ADR (dose related)
What does type B ADR stand for
Bizarre (ideosincratic)
What does type C ADR stand for
Chronic
What does type D ADR stand for
Delayed
What does type E ADR stand for
End of treatment
What does type E ADR stand for
End of treatment
What are some features of type A ADRs
Common and related to pharmacological reactions of drugs
Predictable effects
Low mortality
High morbidity
Why might type A reactions occur
1- pharmaceutical variation : changes in bioavailability
-out of date formulations
- contamination
2- pharmacokinetic variation : liver disease
- renal disease
- cardiac disease
3- pharmacodynamic variation : changes in fluid / electrolyte balance
What’s an example of pharmaceutical variation
Outdated tetracycline
- once out of date breaks down into anhydrotetracycline which is toxic and can cause fanconis syndrome
- which causes an impairment in proximal tubule function
- meaning substances that are usually absorbed back into the blood are lost in the urine
What’s an example of pharmacokinetic variation
E.g. liver disease
- severe hepatitis or advanced cirrhosis can reduce clearance of drugs
- means first pass metabolism will be reduced, so more drug gets into the system unchanged, possibly causing a class A ADR
What’s an example of pharmacodynamic variation
E.g. digoxin (used to treat heart disease)
- it works by blocking the Na/k pump of cardiac muscle cells
- when potassium levels are low, more digoxin can bind
- increases its effects - toxic
Hypernatururea
Increase in sodium in the urine
What’s one way to treat a type A ADR
By changing the amount of the drug administered
What are the features of a type B ADR
Uncommon and not related to the pharmacological reactions of drugs.
Unpredictable
High mortality/ low morbidity
How can type B ADRs be managed
By withholding and avoiding the drug in the future
Why might type B reactions occur
Immunological reasons
Pseudo-allergic reactions
What’s an example of a Type B immunological reaction
Allergy e.g to penicillin
- can cause anaphylactic shock
What’s an example of a type B pseudo-allergic reaction
Aspirin sensitive asthmatics
— 3-5% of asthma sufferers suffer attacks that can be triggered by aspirin
What is a pseudo allergic reaction
Reactions that resemble allergic reactions but no immunological basis can be found
What are the types of type C ADRs
Tolerance, adrenal suppression, tardiness dyskinesia
What is the adrenal suppression Type C ADR
-the production of glucocorticoid hormones are controlled by negative feedback ( which are used to treat chronic inflammatory conditions)
- prolonged treatment with high does can cause the body to suppress glucocorticoid by the adrenal cortex
