Mohamad-Ali Salloum is a Pharmacist and science writer. He loves simplifying science to the general public and healthcare students through words and illustrations. When he's not working, you can usually find him in the gym, reading a book, or learning a new skill.
Unlocking the Future of Medicine: An In-Depth Exploration of Pharmacogenomics
Mohamad-Ali Salloum, PharmD • December 9, 2023
Share
Understanding Pharmacogenomics:
The world of pharmacology is continually evolving, and one of the most exciting frontiers is Pharmacogenomics. Usually, we treat patients based on their clinical characteristics. But with pharmacogenomics, we take into consideration the genetic variability of drug metabolism and response within each person. This allows us to exactly treat what the patient is suffering from, and at the same time reduce some of the unwanted side effects in some cases.
What are the implications of PG in Pharmacy Practice?
1. Individualized Treatment Plans:
Warfarin, an anticoagulant, poses challenges due to its narrow therapeutic window. Pharmacogenomic testing can identify variations in genes like CYP2C9 and VKORC1, influencing an individual's response to warfarin. This genetic insight enables healthcare professionals to determine the most effective and safe dosage for each patient, reducing the risk of bleeding or clotting events.
2. Prevention of Adverse Reactions:
By identifying genetic factors that may contribute to adverse drug reactions, pharmacogenomics helps prevent unnecessary complications, enhancing patient safety. This proactive approach aligns with the core principle of pharmacy practice: first, do no harm.
3. Optimizing Drug Selection:
Understanding a patient's genetic profile enables pharmacists to choose medications with the highest likelihood of efficacy. This approach reduces the need for trial-and-error approaches, streamlining the medication selection process and enhancing overall patient care. This is important, especially in the time-sensitive cases of cancer patients where they require the most effective treatment as soon as possible to counteract the cancer invasion.
Challenges and Future Directions:
While the promise of Pharmacogenomics is undeniable, there are some challenges that stops it from being used as frequently as it should be such as:
- Cost,
- Accessibility,
- Need for the broader genetic databases.
I listed below some of the examples to help you understand how PharmacoGenomics can contribute to better management of the patient’s disease.
1. Warfarin Dosing:
Warfarin, an anticoagulant, poses challenges due to its narrow therapeutic window. Pharmacogenomic testing can identify variations in genes like CYP2C9 and VKORC1, influencing an individual's response to warfarin. This genetic insight enables healthcare professionals to determine the most effective and safe dosage for each patient, reducing the risk of bleeding or clotting events.
2. Clopidogrel Metabolism:
Clopidogrel, an antiplatelet medication, requires activation by the enzyme CYP2C19. Genetic variations in the CYP2C19 gene can lead to reduced drug activation, affecting the drug's effectiveness in preventing blood clots. Pharmacogenomic testing empowers clinicians to make informed decisions about alternative antiplatelet medications for individuals with specific genetic profiles, optimizing cardiovascular care.
3. Codeine Metabolism:
Codeine, an opioid analgesic, undergoes metabolism to its active form through the enzyme CYP2D6. Some individuals possess genetic variations that result in poor metabolism of codeine, leading to inadequate pain relief. Pharmacogenomics can identify patients who may require alternative pain management strategies, preventing ineffective treatment and potential adverse reactions.
4. Allopurinol and HLA-B Gene:
Allopurinol, used in the management of gout, is associated with a potentially severe adverse reaction known as Stevens-Johnson Syndrome (SJS). The risk of developing SJS is significantly increased in individuals with a specific variant of the HLA-B gene. Pharmacogenomic testing can identify patients at higher risk, allowing healthcare providers to consider alternative gout medications to minimize the risk of this life-threatening reaction.
Conclusion:
The journey into Pharmacogenomics is an ongoing exploration, and your role as future pharmacists is pivotal. With each step, you are not just studying pharmacology; you are becoming architects of a healthcare future that truly puts the patient at the center. Embrace the possibilities, navigate the challenges, and let the principles of Pharmacogenomics guide your path toward a future where the right drug, for the right patient, at the right time becomes more than a mantra—it becomes a reality.
References:
1. Johnson JA. Pharmacogenetics: potential for individualized drug therapy through genetics. Trends Genet. 2003;19(11):660-666.
2. Relling MV, Evans WE. Pharmacogenomics in the clinic. Nature. 2015;526(7573):343-350.
3. Scott SA, Sangkuhl K, Gardner EE, et al. Clinical Pharmacogenetics Implementation Consortium guidelines for CYP2C19 genotype and clopidogrel therapy: 2013 update. Clin Pharmacol Ther. 2013;94(3):317-323.
4. Stanek EJ, Sanders CL, Taber KA, et al. Adoption of pharmacogenomic testing by US physicians: results of a nationwide survey. Clin Pharmacol Ther. 2012;91(3):450-458.
List of Services
ABOUT THE AUTHOR
Mohamad-Ali Salloum, PharmD
Share
Recent articles:
References: Qiang S, Wu J, Zheng D, et al. The effect of stress mindset on psychological pain: the chain mediating roles of cognitive reappraisal and self-identity. Front Psychol. 2025;16. 1 Bosshard M, Gomez P. Effectiveness of stress arousal reappraisal and stressisenhancing mindset interventions on task performance outcomes: a meta-analysis. Sci Rep. 2024. 2 Zhao S, Chen P, Jin L, et al. Unlocking Emotional Well-Being: Evaluation of a Stress Mindset Intervention With a Metacognitive Approach. Emotion. 2025;25(5):1169–1184. 4 Meyer HH, Stutts LA. The Effect of Mindset Interventions on Stress and Academic Motivation in College Students. Innov High Educ. 2024;49:783–798. 7 Crum AJ, Santoro E, Handley-Miner I, et al. Evaluation of the “Rethink Stress” Mindset Intervention: A Metacognitive Approach to Changing Mindsets. J Exp Psychol Gen. 2023. 3 Laferton JAC, Fischer S, Ebert DD, et al. The Effects of Stress Beliefs on Daily Affective Stress Responses. Ann Behav Med. 2020;54(4):258–267. 5 UCSF Stress Measurement Network. Beliefs about Stress . 2026. 6
References: Qiang S, Wu J, Zheng D, et al. The effect of stress mindset on psychological pain: the chain mediating roles of cognitive reappraisal and self-identity. Front Psychol. 2025;16. 1 Bosshard M, Gomez P. Effectiveness of stress arousal reappraisal and stressisenhancing mindset interventions on task performance outcomes: a meta-analysis. Sci Rep. 2024. 2 Zhao S, Chen P, Jin L, et al. Unlocking Emotional Well-Being: Evaluation of a Stress Mindset Intervention With a Metacognitive Approach. Emotion. 2025;25(5):1169–1184. 4 Meyer HH, Stutts LA. The Effect of Mindset Interventions on Stress and Academic Motivation in College Students. Innov High Educ. 2024;49:783–798. 7 Crum AJ, Santoro E, Handley-Miner I, et al. Evaluation of the “Rethink Stress” Mindset Intervention: A Metacognitive Approach to Changing Mindsets. J Exp Psychol Gen. 2023. 3 Laferton JAC, Fischer S, Ebert DD, et al. The Effects of Stress Beliefs on Daily Affective Stress Responses. Ann Behav Med. 2020;54(4):258–267. 5 UCSF Stress Measurement Network. Beliefs about Stress . 2026. 6
A clear, evidence‑based guide to Ramadan fasting, explaining its metabolic, mental, and cardiometabolic benefits, plus practical nutrition, hydration, sleep, and medication strategies for healthy adults and high‑risk patients.
A practical guide to shifting from blaming “human error” to applying ICH GCP E6(R3) system‑level quality, Quality by Design, and risk‑based oversight to prevent repeat deviations in clinical trials.
Learn 5 Whys and Fishbone (Ishikawa) for Root Cause Analysis in clinical research, with practical examples and an interactive quiz—no fluff, just clarity.
A clear, practical guide to CAPA for Clinical Research Associates—covering corrective and preventive actions, real‑world scenarios, and an interactive quiz to reinforce learning.
Boost your health with a simple 30‑minute morning walk backed by science—better heart health, mood, sleep, and energy.
References: Gunes IB, Gunes A. Association Between Eyelid Twitching and Digital Screen Time, Uncorrected Refractive Error, Intraocular Pressure, and Blood Electrolyte Imbalances. Cureus . 2024;16(9):e69249. Available from: https://www.cureus.com/articles/291035-association-between-eyelid-twitching-and-digital-screen-time-uncorrected-refractive-error-intraocular-pressure-and-blood-electrolyte-imbalances Banik R, Miller NR. Chronic myokymia limited to the eyelid is a benign condition. J Neuroophthalmol . 2004;24(4):290–2. Available from: https://scholars.mssm.edu/en/publications/chronic-myokymia-limited-to-the-eyelid-is-a-benign-condition-2 Hallett M. Blepharospasm: recent advances. Neurology . 2002;59(11):1759–60. Available from: https://europepmc.org/abstract/MED/12434791 Defazio G, Livrea P. Epidemiology of primary blepharospasm. Mov Disord . 2002;17(1):7–12. Available from: https://europepmc.org/article/MED/11835433 Zeppieri M, Ameer MA, Jahngir MU, Patel BC. Meige Syndrome. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024. Available from: https://europepmc.org/article/MED/30020730 Zhang Y, Adamec I, Habek M. Superior oblique myokymia: a meta-analysis. J Ophthalmol . 2018;2018:7290547. Available from: https://doi.org/10.1155/2018/7290547 Costa J, Espírito-Santo C, Borges A, et al. Botulinum toxin type A therapy for blepharospasm. Cochrane Database Syst Rev . 2020;11:CD004900. Available from: https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD004900.pub2/abstract Khalkhali M. Topiramate-induced persistent eyelid myokymia. Case Rep Psychiatry . 2016;2016:7901085. Available from: https://europepmc.org/articles/PMC4886081/
References: Sen A, Tai XY. Sleep duration and executive function in adults. Curr Neurol Neurosci Rep. 2023;23:801–813. [link.springer.com] Nature Research Intelligence. Sleep deprivation and cognitive performance. Nature Portfolio. 2023. Available from: https://www.nature.com/… [nature.com] Skourti E, Simos P, Zampetakis A, et al. Long-term associations between objective sleep and verbal memory performance. Front Neurosci. 2023;17:1265016. [frontiersin.org] Hauglund NL, Andersen M, Tokarska K, et al. Norepinephrine‑mediated slow vasomotion drives glymphatic clearance during sleep. Cell. 2025;188(3):606‑622.e17. [cell.com] Shirolapov IV, Zakharov AV, Smirnova DA, et al. The role of the glymphatic clearance system in sleep–wake interactions and neurodegeneration. Neurosci Behav Physiol. 2024;54:199–204. [link.springer.com] Kong Y, Yu B, Guan G, et al. Effects of sleep deprivation on sports performance: a systematic review and meta-analysis. Front Physiol. 2025;16:1544286. [frontiersin.org] Gong M, Sun M, Sun Y, et al. Effects of acute sleep deprivation on sporting performance in athletes. Nat Sci Sleep. 2024;16:—. [tandfonline.com] Dean B, Hartmann T, Wingfield G, et al. Sleep restriction between consecutive days of exercise impairs cycling performance. J Sleep Res. 2023;32(3):e13857. [onlinelibr....wiley.com] Mah CD, Mah KE, Kezirian EJ, Dement WC. The effects of sleep extension on athletic performance in collegiate basketball players. Sleep. 2011;34(7):943–950. [psycnet.apa.org] Cunha LA, Costa JA, Marques EA, et al. Impact of sleep interventions on athletic performance: a systematic review. Sports Med Open. 2023;9:58. [link.springer.com] Teece AR, Beaven CM, Argus CK, et al. Daytime naps improve afternoon power and perceptual measures in elite rugby union athletes. Sleep. 2023;46(12):zsad133. [academic.oup.com] Mesas AE, Núñez de Arenas-Arroyo S, Martinez-Vizcaino V, et al. Daytime napping and cognitive/physical sport performance: meta-analysis of RCTs. Br J Sports Med. 2023;57(7):417–27. [bjsm.bmj.com] Haines Roberts SS, Teo WP, Warmington SA. Effects of training and competition on the sleep of elite athletes. Br J Sports Med. 2019;53(8):513–522. [bjsm.bmj.com] Walsh NP, Halson SL, Sargent C, et al. Sleep and the athlete: 2021 expert consensus recommendations. Br J Sports Med. 2021;55(7):356–368. [bjsm.bmj.com] Janse van Rensburg DC, Fowler PM, Racinais S. Practical tips to manage travel fatigue and jet lag in athletes. Br J Sports Med. 2021;55(15):821–822. [bjsm.bmj.com] Watson NF, Badr MS, Belenky G, et al. Recommended amount of sleep for a healthy adult: AASM/SRS consensus statement. Sleep. 2015;38(6):843–844. [aasm.org] Centers for Disease Control and Prevention. FastStats: Sleep in adults. CDC. 2024. Available from: https://www.cdc.gov/sleep/… [cdc.gov]