Adding Amantadine or Duloxetine to Pregabalin on Occurrence of Post Mastectomy Pain Syndrome

The Effect of Adding Amantadine or Duloxetine to Pregabalin on Occurrence of Post Mastectomy Pain Syndrome; Randomized Controlled Study

This study aims to evaluate the additive effect of Amantadine or Duloxetine to Pregabalin on development of post mastectomy pain syndrome

Post mastectomy pain syndrome (PMPS) is considered one of the most common types of CPSP with incidence ranging between 20% - 50%.

Pregabalin is one of the drugs that can reduce the excitability of the dorsal horn neurons. It is a γ-aminobutyric acid analogue that binds to α2-δ subunits of the voltage-gated calcium channels in the central nervous system.

Duloxetine is an SNRI that increases serotonin and norepinephrine levels in the central nervous system, which helps modulate pain pathways. Originally developed for depression and anxiety, it is also used for chronic pain conditions such as fibromyalgia, diabetic neuropathy, and chronic musculoskeletal pain.

Amantadine is a noncompetitive antagonist of N-methyl-D-aspartate (NMDA) receptors. These receptors play a significant role in the development of central sensitization, acute opioid tolerance, and opioid-induced hyperalgesia.

Inclusion Criteria:

• Age from 18 to 65 years.
• American society of anesthesiologists (ASA) Physical status II, III.
• Body mass index (BMI): (20-40) kg/m2.
• Type of surgery: patients undergoing modified radical mastectomy for breast cancer.

Exclusion Criteria:

• Patient refusal.
• Patients with Known sensitivity or contraindication to drug used in the study.
• History of psychological disorders and/or chronic pain and drug abuse patients.
• Previous administration of antidepressants, anticonvulsants, or opioids before surgery.
• Severe respiratory or cardiac disorders.
• Advanced liver or kidney disease.
• Previous breast surgery