GABA and L-theanine safe premedication options for anxiolysis among major elective surgery patients, finds study

Preoperative anxiety influences the results of anesthesia and surgery, while benzodiazepines have negative effects on psychomotor performance and cause excessive sedation. L-theanine, found in green tea, has stress-reducing, anxiolytic, and alpha activity-modulating properties, benefiting mental state and sleep quality. Gamma-aminobutyric acid (GABA) is a non-proteinogenic amino acid and a phytochemical that serves as the primary inhibitory neurotransmitter in the mammalian brain, beneficial for anxiety and stress regulation. Recent research paper examined the effects of L-theanine, GABA, and alprazolam on preoperative anxiety, sedation, and cognitive function in patients undergoing major elective surgeries. The study compared the primary outcomes of anxiety, sedation, and cognitive performance across the three groups, and also evaluated the adverse reactions.

Study Participants and Measures

The study included 168 patients aged 18-55 years with ASA physical status I and II, who were randomly assigned to receive oral L-theanine 200mg, oral GABA 500mg, or oral alprazolam 0.25mg. Anxiety levels were assessed using a visual analog scale (VAS), sedation was measured using the Ramsay sedation score, and cognitive/psychomotor function was evaluated with the digit symbol substitution test (DSST) and trail making test (TMT) parts A and B. The results showed that all three drugs were effective in reducing preoperative anxiety, with alprazolam producing the greatest decrease in anxiety scores. However, alprazolam also caused the highest degree of sedation compared to GABA and L-theanine. GABA and L-theanine did not significantly impair sedation levels.

Cognitive and Psychomotor Function

In terms of cognitive and psychomotor function, alprazolam was found to worsen performance on the DSST and TMT tests, indicating impairment in these domains. Conversely, GABA and L-theanine either maintained or improved cognitive and psychomotor test scores compared to baseline. The authors concluded that both GABA and L-theanine are effective premedication options, providing anxiolysis with minimal sedation and even improvements in cognitive skills, unlike the sedative and cognitive-impairing effects seen with alprazolam. The study suggests GABA and L-theanine may be safer and more suitable premedication alternatives compared to benzodiazepines like alprazolam. Overall, this study provides important insights into the differential effects of these three premedication options on preoperative anxiety, sedation, and cognitive function.

Key Points

Here are the 6 key points from the research paper:

1. The study compared the effects of L-theanine, GABA, and alprazolam on preoperative anxiety, sedation, and cognitive function in 168 patients undergoing major elective surgeries.

2. Anxiety levels were measured using a visual analog scale (VAS), sedation was assessed with the Ramsay sedation score, and cognitive/psychomotor function was evaluated using the digit symbol substitution test (DSST) and trail making test (TMT).

3. All three drugs effectively reduced preoperative anxiety, with alprazolam producing the greatest decrease. However, alprazolam also caused the highest degree of sedation compared to GABA and L-theanine.

4. In terms of cognitive and psychomotor function, alprazolam impaired performance on the DSST and TMT tests, indicating cognitive impairment. Conversely, GABA and L-theanine either maintained or improved cognitive and psychomotor test scores.

5. The authors concluded that GABA and L-theanine are effective premedication options, providing anxiolysis with minimal sedation and even cognitive improvements, unlike the sedative and cognitive-impairing effects seen with alprazolam.

6. The study suggests GABA and L-theanine may be safer and more suitable premedication alternatives compared to benzodiazepines like alprazolam for patients undergoing major elective surgeries.

Reference –

Deshpande SS, Kurdi M, Baiju A, Athira AS, Sarasamma AG, Gangadharan AK. Comparison of the effects of two amino acids, Gamma‑aminobutyric acid (GABA) and L‑theanine, on sedation, anxiety, and cognition in preoperative surgical patients – A randomized controlled study. J Anaesthesiol Clin Pharmacol 2024. DOI: 10.4103/joacp.joacp_417_23.