IST: why it's so important to get the correct dose for every patient
It's a familiar situational irony that many life-saving medications and courses of treatment used in modern medicine double as potentially lethal poisons. Well-known examples include vaccines and chemotherapy.
In transplantation, the organ itself is the “treatment” of the patient’s ailment, but transplanting a donor organ into a recipient is the equivalent of planting a ticking time-bomb in their body. Even in cases of a close match, the body’s immune response mounts an attack against the foreign organ, causing graft loss and rendering the organ useless.
Enter Immunosuppressant Therapy (IST), another example of a regimen of vital poison which dulls the transplant patient’s immune response, lowers the body’s defenses, and keeps it from rejecting their new, life-saving organ.
Although a certain level of immunosuppression is necessary to avoid graft loss, the same drugs that lower the body’s defense mechanisms against the new organ lower them categorically against myriad other infections.
If dosages are wrong, the consequences are devastating. For that reason, it is of paramount importance to get the right combination of immunosuppressive drugs and to calibrate the dosage exactly in order for the “poison” to stay within its narrow therapeutic window.
Importantly, it is becoming increasingly clear that no part of this delicate balance of IST can be struck using a “one size fits all” approach. Rather, each individual patient needs to be carefully and holistically assessed based on race, age, medical history etc and continually monitored in order for the physician to have a clear picture of how the patient is responding to the therapy and to be able to make adjustments. This process is referred to as Therapeutic Drug Monitoring (TDM).
Given the delicate individual balance that must be struck and the devastating consequences if immunosuppressant levels are wrong, it is shocking that the biggest problem with IST isn’t actually the calibration of medication by the practitioner, but rather the non-adherence of patients to their post-op regimens.
A shocking number of patients miss their doses, making it all the more difficult for doctors to remain informed about their patients’ status and to make changes accordingly.
As such, there has of late been a call for a new solution: the use of blood microsampling as the method of choice for testing IST. Blood microsampling methods allow a small volume of blood to be taken via a finger prick by patients themselves from the comfort of home, and then sent by post for analysis.
This cuts out time spent traveling to and from the clinic and eliminates the need for painful blood draws where large volume samples are taken, but it still gets the doctors the results they need in order to calibrate the patient’s IST regimen.
In a world of increasingly holistic and personalized medicine, we need to begin to consider individualized options like blood microsampling that allow for better and more frequent means of getting vital information into doctors’ hands, while allowing transplant patients the freedom to do so comfortably and on their own schedule.
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