Pharmacogenetics Notes PDF

# Pharmacogenetics * Study of how a patient's genomes affect drug response * Helps individualize optimal drug treatment regimens * Helps decrease drug reactions * Promotes drug regimen adherence * Reduces overall healthcare costs * 1865 Gregor Mendel was the first to explain dominant and recessive...

# Pharmacogenetics * Study of how a patient's genomes affect drug response * Helps individualize optimal drug treatment regimens * Helps decrease drug reactions * Promotes drug regimen adherence * Reduces overall healthcare costs * 1865 Gregor Mendel was the first to explain dominant and recessive genes * 1953 James Watson and Francis Crick discovered DNA * 2003 Human Genome project completed mapping of genes in humans * 2015 Precision Medicine Initiative was launched to expand. The treatment and prevention of disease taking into account a person's genes, environment and lifestyle Drugs are not "one size fits all" Drug prescribing is generally based on age, weight, gender and liver/kidney function 50% of patients stop taking a medication d/t side affects ## Clinical Uses of Pharmacogenetics **Patients who benefit most from pharmacogenetics:** * Those taking multiple prescription drugs * Those not responding to current therapy * Those having adverse drug reactions * Those taking black box warning drugs **Pharmacogenetic testing is not available for all drugs** One single test doesn't determine how a patient will respond to all drugs ## Individual Variation in Metabolism of Select Drugs | Drug | Description | |---|---| | Mercaptopurine | (chemo/immunosuppressant): FDA recommends genetic testing before admin in patients with ALL. r/t. Interference in metabolism of drug causing an increased severity in side effects and increased risk of infection | | Irinotecan | (used for treatment of colon ca): d/t inability to eliminate the drug leading to severe diarrhea/neutropenia and life-threatening infections | | Abacavir | (HIV medication): may develop fatal multiorgan hypersensitivity | | Warfarin | (treatment and prevention of blood clots): persons with specific genetic makeup can experience life-threatening bleeding d/t decreased clearance of medication, require adjusted dosing. | | Clopidogrel | (Plavix) antiplatelet: may be at risk for clot formation d/t inability to convert prodrug to active drug | | Opioids | decreased pain relief d/t. Lack of drug-metabolizing enzyme. | | Mental Health Drugs | may have toxic drug reactions d/t inability to metabolize drug | | Carbamazepine | (anti-seizure): may have increased risk of developing Steven-Johnson syndrome (flu-like symptoms and painful rash that spreads and blisters) or toxic epidermal necrolysis | ## Legal and Ethical Issues * **Privacy** * Who has access to patient's genetic information? * Who owns genetic information * Concerns about patient "labeling" * **Autonomy** * Patient may consent to or refuse genetic testing * Patient may change their mind about testing * **Justice** * Equal and fair treatment for all **2008 Genetic Information Non-discrimination Act:** Prohibits insurance companies from requiring genetic testing to obtain health insurance, and from using genetic information to determine coverage and permiums ## Nursing Process: Pharmacogenetics * Assessment * Diagnosis * Planning * Nursing interventions * Evaluation **Safety:** protection of the patient from potential or actual harm, basic human need **Assessment** * Assess family history back three generations. * Determine side effects/adverse effects to drug therapy **Patient Problem** (develop nursing diagnosis from these) * Anxiety * Coping * Need for health teaching **Planning** * Integrate patient preferences and family implications into developing evidence-based plans of care **Nursing interventions** * Refer identified patients to genetic counseling as needed * Guide patients in the implications and uses of genetic results. * Ensure patient knows to report genetic findings to all healthcare providers. **Evaluation** * Evaluate effectiveness of pharmacogenetic interventions and treatment on patient outcomes