Rational drug use Flashcards
dose
does the person have comorbidities that could affect the pharmacodynamics
route of administration
vomiting patient, unconscious
duration
prevent drug resistance with bacteria
advice
how to take drugs, when to stop
monitoring
making sure they benefit and not harmed
principles of rational drug use
drug dose route of administration duration advice monitoring
define problem
diagnosis and severity
set therapeutic objectives
what are we trying to achieve
select therapy
non drug
drug therapy
p drug
efficient
safe
suitable
cost effective
patient drug
co-morbidities, cautions, contraindications
drug to drug interactions
convenience and compliance
prescribing
information- onset of action
instructions
warnings
monitor therapy
objectives being achieved?, adherent, review diagnosis
adverse drug event
medical occurrence associated with the use of medicinal product but not necessarily causally related
adverse drug reaction
a response to a drug which is noxious and unintended which occurs at doses normally used
type A drug reaction
augmented
dose dependent
common/ predictable
type b
bizarre
dose independent
rare/unpredictable
pharmacovigilence
The science and activities relating to the detection, assessment, understanding and prevention of adverse effects or any other drug-related problems.” Ultimately these activities are aimed at protecting patients and the public from drug-related harms.
risk mitigation
Take a full history, including concomitant illness, medication (including OTC, CAT, SOA meds) and allergies
Heed contra-indications, cautions and warnings
Avoid unnecessary drugs
Avoid drug interactions
Use correct dose
Conduct appropriate monitoring
Report suspected ADRs
causality assessment (WHO-UMC)
a- time relationship between drug use and event b- absence of other competing causes(meds, disease itself) c- de-challenge d- re-challenge Definitely- all 4 Probably / Likely- first 3 Possibly- a only Unlikely- no a and b Conditional / Unclassified Unassessable / Unclassifiable
bradford hill criteria
strength of association
temporality- cause precedes outcome
consistency- same answers in different situations
specificity- specific cause for a specific effect
dose response- increased exposure leads to increased effects
biological plausibility- relationship could be explained by biological mechanisms
Naranjo scale
1.
Are there previous conclusive reports on this reaction?
2. Did the adverse event appear after the suspected drug was administered?
3. Did the adverse event improve when the drug was discontinued or a specific antagonist was administered?
4. Did the adverse event reappear when the drug was re-administered?
5. Are there alternative causes that could on their own have caused the reaction?
6. Did the reaction reappear when a placebo was given?
7. Was the drug detected in blood or other fluids in concentrations known to be toxic?
8. Was the reaction more severe when the dose was increased or less severe when the dose was decreased?
9. Did the patient have a similar reaction to the same or similar drugs in any previous exposure?
10. Was the adverse event confirmed by any objective evidence?
0-doubtful
1-4 possible
5-8 probable
greater than 9- definite
stages of drug developments
Identification of pharmacological target
Screening to identify molecules that interact with target
Molecules refined: chemistry, computer modelling
In vitro tests
Formulation
Toxicology
phase 1-4 clinical trials
generic drugs
Generics are identical in dosage form, safety, strength, route of administration, quality, performance characteristics and intended use.
generic drug regulations
meet same standard as innovator drug
bioequivalent (smiliar bioavailability, safety, efficacy, AUC, Cmax and Tmax, and the 90% confidence interval between 0.8 and 1.25) to the innovator drug
pass same quality standards as innovator drug
