Pharmacovigilance Flashcards
What is pharmacovigilance
Pharmacovigilance - identification, assessment and subsequent prevention of adverse drug reactions while optimising benefits
Responsibility lies with prescribers, patients and carers
Describe the origin of pharmacovigilance
Thalidomide prescription is the origin of pharmacovigilance
Thalidomide was used to help morning sickness in women but was found out to be a teratogen causing birth defects, most notably phocomelia
Describe a case of poor communication by the health care community that lead to people taking more risks due to the findings of the investigation being miscommunicated
COCP was found to increase the risk of VTE - found in 1960s via ADR reports
COCP dose was decreased without reducing efficacy
When this was discovered by the public, there was decreased use of OCs without alternative contraception leading to increase induced abortion
Pregnancy is much risker than the use of OCs but due to poor communication, this was not brought to the publics attention -> they chose not to use OCs and took more risks instead
What factors are invovled in whether a patient will have an ADR to a specific drug
Dose
Time
Susceptibility
Name the four main modes of action for an ADR and give an example for each
Exaggerated response, e.g. bleeding with warfarin
Desired pharmacological effect at alterantive/additional site, e.g. GTN causing headache
Additional/secondary pharmacological effect, e.g. QT length
Triggering immunologcial respnose, e.g. anaphylaxis
Name some advantages of the yellow card scheme
Simple - allows viewing of all drugs all the time
Timely and theoretically inexpensive
Detects common and rare reactions
Accessible by all health care professionals
Name some disadvantages of the yellow card scheme
Inevitable and unquantifiable under-reporting
Positive selection bias
Duplicatoin
Effect of publicity
Incomplete poor quality data
What is pharmacogenetics
Pharmacogenetics - how an individual gene may affect the respnose to a drug or the drugs response on the body
What is pharmacogenomics
Pharmacogenomics - how a drug affects the whole genome. Considers the epigenetics of the drug
Patients can be tested to see if they will react to a certain drug, give two examples of this
Abacavir - used to treat HIV. Hypersensitivity reaction in 8% of patients. Due to split antigen reaction which can be screened for
Carbamazepine - have cutaneous reaction due to split antigen reaction
Why should Africans/Caribbeans not be given ACEi/ARBs as the first line of treatment for hypertension
Africans/Caribbeans have a lower renin activity -> ACEi/ARBs less useful
Angioedema is also more prevalent in these populations and as ACEi can cause angioedema, they should not be used
Seen in population level but may vary in individuals
Name the enzyme that is responsible for 25% of drug metabolism
CYP 2D6
Which ethnicity can have genetic mutations in the gene coding for CYP 2D6 and what is the result of this
Caucasians can carry two null alleles at the gene locus have no CYP 2D6 production while others have decreased or increased activity of the enzyme
The result of this is that there can be decreased or increased metabolism of the drugs that are metabolised by this enzyme, e.g. antidepressants, antipsychotics, beta-blockers, opioids
What are some uses of pharmacogenetics in therapeutics
Personalising drug therapy - screening of gene varients to detemine receptors and enzymes in the patient
Cancer - target particular somatic changes in neoplastic cells
Statins - predicting ADRs
Vaccines for allergies
Address prophylatic viral vaccine failure and ADRs by following genetic polymorphisms and their effect on innate and adaptive immune response
