Pharmacogenomics | PGx

Healthcare professionals often prescribe one of several suitable medications when beginning pharmacological therapy to treat a specific illness. Drug dosages and timing are often determined by the average person's estimated rate of metabolism and bodily clearance. They determine a "standard" dose based on details like age, sex, and weight. Clinically, however, each person responds uniquely to treatment and healthcare practitioners must make adjustments. Depending on how the patient is reacting to the medication and whether they are having any unfavorable or dangerous side effects, the healthcare provider may, for instance, change the drug dosage or switch to a different therapy. Occasionally, a patient may discover that a medication that has been effective causes symptoms when that person starts taking an additional drug.

Blood tests are used to measure drug concentrations or side effects, and drug dosages may be changed to keep the drug level within a prescribed therapeutic range. Therapeutic drug monitoring refers to the monitoring of drug concentration. A alternative medication may be prescribed if increasing the dosage is ineffective in treating or managing the patient's condition or if the patient is still experiencing side effects.

Pharmacogenetics gives medical professionals the chance to tailor pharmacological therapy for patients based on their genetic make-up. One important developing area of testing involves assessing individuals before beginning medication therapy to determine their likely response to various drug classes. When selecting current and future pharmacological regimens and dosages, this genetic information may be helpful to both the patient and the healthcare professional. Pharmacogenetics is already assisting medical professionals in the predetermination of appropriate therapies and dosages for some medications, giving them a better chance of obtaining the desired therapeutic benefit while reducing the risk of side effects.

Genes are the fundamental building blocks of genetic material; they are DNA segments that typically contain instructions for producing particular proteins, such as enzymes. The majority of genes are present in two copies per individual, one from each parent: the person's mother and father. A particular genetic code, which is a series of nucleotides, makes up each gene (A, T, G, or C). One of the four nucleotides is more common in the general population than the other three for each nucleotide position in the gene. "Wild type" usually refers to this nucleotide. One copy of a person's genes must have a nucleotide that differs from "wild type" for that person to be considered to have the condition.

All populations have nucleotide or genetic variances, often known as polymorphisms or mutations. Some genetic variations are benign, meaning they have no known detrimental effects, or they may be related to physical characteristics like height, eye color, and hair color. Certain disorders may be caused by other genetic variations. The varying reaction to a given medicine may be linked to additional polymorphisms.

Pharmacogenetic studies search for genetic variations linked to a range in reaction to a given medicine. These variations can be found in genes that produce immune response proteins, therapeutic targets, or drug-metabolizing enzymes. Pharmacogenetic studies can detect whether a variant is heterozygous or homozygous, which may affect how well an individual responds to a medication.

At any point throughout therapy, a medical professional may check a patient's DNA for specific changes known to affect how they respond to a medication (for example, prior to treatment, during initial phase of treatment, or later in the treatment). The individual's clinical data, such as age, weight, health, and any medications they are taking, may be linked with the test findings to help customize therapy. The medical professional may occasionally utilize this information to change the medication's dose or occasionally to select an alternative medication. Pharmacogenetic testing is meant to supplement the healthcare provider's knowledge, although it might not be a substitute for therapeutic drug tracking.

A person's genetic makeup does not alter over time, hence pharmacogenetic testing for a particular gene is only done once. A single gene or several genes may be ordered, depending on the drug. Warfarin is an illustration of a drug for which many genes are typically assessed because it may be impacted by genetic variation in CYP2C9 and VKORC1.

Testing may be required before beginning a particular drug therapy or if someone already taking a medication is suffering side effects or difficulty establishing and/or maintaining a stable dose. A person may occasionally not experience such problems until additional medications are added to or stopped that have an impact on the metabolism or effect of the drug in question.