Narrow therapeutic window
Tacrolimus suppresses the immune response and prevents organ transplant rejection. The problem is that the range of safe and effective concentrations is very narrow, and the absorption and metabolism of the drug varies greatly between patients and changes over time. Insufficient concentration leads to transplant rejection, excessive concentration leads to kidney damage, arterial hypertension, diabetes mellitus and neurological complications. Therefore, the dose is selected not by weight, but by the actual concentration in the blood, which is monitored regularly: often in the first months after transplantation, less often in the future. Blood is donated strictly before taking the next dose: the minimum residual concentration is measured. Many drugs and even grapefruit juice change the level of tacrolimus, which also requires monitoring.
How to prepare to donate blood
- on an empty stomach 8–12 hours, you can drink water
- Eliminate alcohol and intense exercise per day
- no smoking in an hour
- donate blood before physiotherapy, x-rays and massage
- Take medications in advance by agreeing with your doctor
How to read the result
Reference values depend on the method and equipment of the laboratory, so it is correct to compare results only within the same laboratory. A deviation of a few percent from the normal limit in itself rarely matters - the overall picture and dynamics are important.
The analysis must be interpreted by a doctor: an isolated indicator without a clinical context is often misleading and leads to unnecessary examinations.