Inclusion Criteria:

1. The patient correctly gave written informed consent to participate in the study;

2. Men or women between the ages of 18 and 65 inclusive at the time of signing the
informed consent;

3. Patient after a minimum of 6 months from the documented detection of SARS-CoV-2
infection (document confirming the history of the disease, including a positive
result of the PCR or antigen test, certificate of convalescence; medical
documentation confirming the infection; the condition is also considered fulfilled
in the case of documented infection asymptomatic);

4. During the screening, the patient meets the criteria for the diagnosis of chronic
fatigue syndrome (CFS) according to the National Academy of Medicine (2015);

5. Women:

a) incapable of having children (post-menopausal or child-bearing, subjected to
permanent sterilization); (b) of childbearing potential with a negative pregnancy
test result at screening and using a highly effective method of contraception
throughout the IMP use and for 7 days after the last IMP use.

6. The patient agrees to participate in all activities provided for in the study.

7. The patient is able to understand the information presented and give informed
consent to participate in the study prior to screening.

Exclusion Criteria:

1. Vital functions disorders;

2. Documented hypersensitivity to pregabalin or any of the excipients of the
formulation (i.e., lactose);

3. Moderate or severe depression during treatment or present during psychiatric
evaluation at baseline;

4. Concurrent treatment with opioids or other antiepileptic drugs (including tramadol,
buprenorphine, morphine, oxycodone, gabapentin, duloxetine);

5. Pregnant or breastfeeding women.