People can respond differently to the same medication. A medicine that is effective and well tolerated by one person may be less effective, require a different dose, or cause more side effects in another.
Pharmacogenomic testing, also known as pharmacogenetic testing, PGx testing, medication response genetic testing or drug–gene testing, examines selected genetic variations that may influence how the body processes and responds to certain medicines.
At Manaha Clinic, pharmacogenomic test results are interpreted by a qualified doctor alongside the person’s symptoms, diagnosis, medical history, current medicines, previous treatment response and overall health.
What Is Pharmacogenomic Testing?
Pharmacogenomics is the study of how a person’s genes may affect their response to medicines. It combines pharmacology — the study of medicines — with genomics, the study of genes and their functions.
A PGx test looks for selected variations in genes involved in areas such as:
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medication metabolism
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activation or breakdown of medicines
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transportation of medicines within the body
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likelihood of therapeutic response
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susceptibility to certain medication-related adverse effects
The results may help the treating doctor understand whether a particular medicine is likely to be processed normally, more slowly, or more rapidly. In some situations, the findings may support the consideration of a different dose, closer monitoring, or an alternative medicine. Pharmacogenetic findings must always be considered together with clinical information.
Pharmacogenomic Testing and Personalised Medicine
Pharmacogenomic testing is one component of personalised medicine, also called precision medicine.
Rather than assuming that every person will respond to a medicine in the same way, precision medicine considers individual factors such as:
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genetics
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age and body composition
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diagnosis and symptoms
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liver and kidney function
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other medical conditions
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concurrent medicines
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previous medication response
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lifestyle and environmental factors
PGx testing provides an additional source of information that may help doctors make more individualised prescribing decisions. It does not replace clinical evaluation or medical judgement.
Medication metabolism
Whether the body may process a particular medicine more slowly, normally or more rapidly.
Possible medication effectiveness
Whether a genetic variation has been associated with a reduced or altered response to a medicine.
Risk of certain side effects
Whether the person may have an increased genetic susceptibility to specific adverse effects associated with a medicine.
Potential dose considerations
Whether established pharmacogenomic guidance suggests that dose adjustment or closer monitoring may be considered.
Possible alternative medicines
In selected situations, the report may indicate that the treating doctor should consider another medication.
The test findings are probabilistic rather than absolute. They indicate possible differences in medication response and do not predict with certainty whether a medicine will or will not work.
What Can a Medication Response Genetic Test Tell You?
Pharmacogenetic Testing for Psychiatric Medications
Pharmacogenomic testing is increasingly discussed in psychiatry because genetic variations may influence the metabolism or response to selected:
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antidepressants
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antipsychotics
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mood stabilisers
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anti-anxiety medicines
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ADHD medicines
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anticonvulsants
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sleep-related medicines
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medicines used in addiction treatment
Depending on the genetic panel, relevant genes may include enzymes and transporters such as CYP2C19, CYP2D6, CYP2B6, CYP3A5, UGT enzymes, NAT2, DRD-related genes and others.
However, psychiatric medication response is influenced by many genetic and non-genetic factors. A result indicating “use with caution” does not automatically mean that the medicine is unsafe, and a result indicating “use as directed” does not guarantee that it will be effective or free from side effects.
How Is the PGx Test Conducted?
Clinical Use, Children and Important Limitations
Manaha Clinic offers clinician-guided pharmacogenomic testing in Hyderabad for children, adolescents and adults. The test may provide useful information about how selected genetic variations could influence medication metabolism, effectiveness or the likelihood of certain side effects.
PGx testing may also be considered for children and adolescents when medication treatment is being planned or reviewed, particularly where there have been:
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significant or unexpected medication side effects
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limited response to previous treatment
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unusual sensitivity to standard or low doses
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a complex medication history
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a likely need for longer-term psychiatric or neurological medication
Important limitations
Pharmacogenomic testing cannot identify a “perfect” medicine or guarantee that a treatment will be effective or free from side effects. The results must always be interpreted alongside the person’s symptoms, medical history, current medicines and previous treatment response, and no medication should be started, stopped or changed solely on the basis of the PGx report.
