The goal of this clinical trial is to study postoperative analgesia in patients undergoing CABG. And learn if tafalgin (tyrosyl-D-arginyl-phenylalanyl-glycine amid) treats pain not inferiory then morphine. The main questions it aims to answer are:

Does tafalgin (tyrosyl-D-arginyl-phenylalanyl-glycine amid) lower the VAS score same way as a morphine? What medical problems do participants have when taking tafalgin (tyrosyl-D-arginyl-phenylalanyl-glycine amid)?

Participants will:

Group (1)- subcutaneous single dose of morphine 10 mg would be administred based on VAS score > 3 during 24 hours after CABG.

Exprimental group (2)- subcutaneous single dose of tafalgin (tyrosyl-D-arginyl-phenylalanyl-glycine amid) - 0.4 mg would be administred based on VAS score > 3 during 24 hours after CABG.

Efficacy was assessed using the VAS scale decreassion. Hemodynamic parameters and arterial blood gases were also assessed.

Inclusion Criteria:

• ASA score less then 3, Signed inform consent, Absence of preoperative drugs administration that affects patient's perception of pain, No active infection process, BMI index >18,5 kg\m2 and < 35 kg/m2, CABG, Age 18-75 years

Exclusion Criteria (the presence of at least one is sufficient):

• Failure to meet the inclusion criteria.
• High severity according to ASA (class IV or higher), which is associated with a high probability of prolonged mechanical ventilation, hemodynamic instability, and inability to use drugs affecting cardiac output and/or total peripheral vascular resistance.
• Contraindications to the use of tafalgin and/or morphine in accordance with the approved Summary of Product Characteristics (hypersensitivity to tafalgin, morphine, other opioids, or any excipients).
• Pregnancy or lactation.
• Acute or prolonged chronic intoxication with drugs or substances depressing the central nervous system (alcohol, barbiturates, opioid drugs, benzodiazepines).
• Use of monoamine oxidase inhibitors (MAOIs) or less than 14 days since their discontinuation.
• Liver cirrhosis, Child-Pugh class C.
• Acute renal failure requiring renal replacement therapy.
• Unresected malignant neoplasm.
• Mesenteric thrombosis or another severe abdominal pain syndrome of unclear etiology at the time of inclusion.
• Simultaneous participation in another clinical study.
• Marked CNS depression due to any cause, except for acute poisoning.
• COPD stage III and/or bronchial asthma in the exacerbation phase.
• Any clinically significant condition, disease, or circumstance in the medical history that, in the opinion of the investigator, precludes participation in the study.
• Psychiatric, physical, or other conditions preventing adequate assessment of the patient's behavior or proper compliance with the study protocol.
• Postoperative hemodynamic instability requiring high-dose inotropic and/or vasopressor support (epinephrine > 0.1 μg/kg/min, dopamine > 10 μg/kg/min, norepinephrine > 0.2 μg/kg/min) and/or mechanical circulatory support.
• Refusal to participate in the study.