Why doesn’t my platelet count rise after taking Avatrombopag/Sukesin for 5 days?

In 2018, Avatrombopag became the first thrombopoietin (TPO) receptor agonist approved by the U.S. Food and Drug Administration (FDA) as an alternative to platelet transfusions for the treatment of thrombocytopenia in patients with chronic liver disease (CLD) scheduled for surgery. Avatrombopag binds to a site on the TPO receptor that is different from endogenous TPO and mimics the biological effects of TPO, resulting in an increase in platelet counts. Efficacy and safety data have been reported with avatrombopag in patients with thrombocytopenia.

The platelet-raising effect of avatrombopag is closely related to the patient's baseline platelet level. According to clinical studies and drug inserts, the response rate of avatrombopag may be lower in patients with low baseline platelets (eg, 10 to <20×10^9/L). This may be because the bone marrow hematopoietic function of these patients has been severely affected, and it is difficult to significantly increase the platelet count in a short period of time with drug treatment alone.

The platelet-raising effect of avatrombopag is short-term and time-dependent. Generally speaking, after taking avatrombopag, platelet counts usually begin to increase within days 3 to 5, reach a peak on days 10 to 13, and then gradually decrease, returning to baseline levels around day 35. Therefore, if a patient checks their platelet count immediately after taking the drug for five days, the peak effect of the drug may not have been reached, causing it to appear that the platelet count is not rising.

In addition, factors such as patient differences, drug metabolism ability, and concomitant medication may also affect the efficacy of avatrombopag. For example, if the patient has a drug metabolism disorder or is taking a drug that may affect the absorption or metabolism of avatrombopag, this may result in reduced drug efficacy. If the patient fails to take the medication on time, stops taking the medication at will, or changes the dose, the efficacy of the medication may be unstable or reduced.