Effect of amitriptyline on gastrointestinal function and brain-gut peptides: A double-blind trial

Table 1 Demographic and baseline characteristics of study in healthy volunteers

Variable	Group A (n = 14)	Group B (n = 14)	P value
Age (yr)	27.71 ± 8.56	32.5 ± 13.36	0.26
Sex (male)	7	7	1
BMI (kg/m2)	20.09 ± 1.41	20.21 ± 1.42	0.82
HAMD	2.36 ± 1.28	1.71 ± 1.20	0.29
HAMA	2.71 ± 1.73	3.36 ± 1.45	0.18
Cross-sectional area of the proximal stomach (cm2)
200 mL	17.13 ± 4.53	18.75 ± 2.30	0.08
400 mL	29.19 ± 6.24	30.76 ± 6.59	0.95
600 mL	40.92 ± 11.5	40.66 ± 7.28	0.35
800 mL	46.21 ± 12.16	46.46 ± 6.81	0.24
Difficulty in drinking water VAS
200 mL	0.79 ± 0.58	1.07 ± 0.62	0.23
400 mL	1.79 ± 0.58	1.86 ± 0.54	0.71
600 mL	3.21 ± 0.80	3.50 ± 0.65	0.31
800 mL	5.50 ± 0.76	5.43 ± 0.76	0.82
Gastric emptying
5 min	77.65% ± 6.5%	81.46% ± 5.81%	0.67
10 min	62.61% ± 9.85%	65.18% ± 6.77%	0.55
OCTT (min)	88.93% ± 19.03%	81.43% ± 20.14%	0.46
Plasma levels (pg/mL)
MTL	502.66 ± 127.52	440.85 ± 123.25	0.20
Ghrelin	460.06 ± 146.25	444.94 ± 202.43	0.82
NPY	888.88 ± 154.52	913.46 ± 139.32	0.66

Values are represented as mean ± SD. Symptom scores on 10-cm visual analogue scale. HAMD: Hamilton depression rating scale; HAMA: Hamilton anxiety rating scale; BMI: Body mass index; OCTT: Orocecal transit time; NPY: Neuropeptide Y; MTL: Motilin; VAS: Visual analogue scale.

Table 2 Effects of amitriptyline on gastrointestinal function and brain-gut peptides

Variable	Amitriptyline (n = 28)	Placebo (n = 28)	P value
Cross-sectional area of the proximal stomach (cm2)
200 mL	16.51 ± 3.78	16.56 ± 3.98	0.97
400 mL	27.14 ± 5.71	27.84 ± 5.95	0.49
600 mL	34.11 ± 6.11	34.85 ± 6.61	0.39
800 mL	39.58 ± 7.35	40.86 ± 8.45	0.34
Difficulty in drinking water VAS
200 mL	0.93 ± 0.65	0.96 ± 0.56	0.58
400 mL	1.93 ± 0.46	1.82 ± 0.54	0.29
600 mL	2.98 ± 0.85	3.57 ± 0.94	0.001
800 mL	4.57 ± 0.98	5.57 ± 0.82	0.001
Gastric emptying
5 min	78.40 ± 11.71	78.84 ± 7.47	0.87
10 min	66.72 ± 11.63	64.54 ± 10.29	0.47
OCTT (min)	109.29 ± 29.68	96.61 ± 23.9	0.004
Plasma levels (pg/mL)
MTL	461.88 ± 129.66	473.40 ± 122.75	0.61
Ghrelin	526.87 ± 158.44	442.87 ± 176.79	0.04
NPY	965.64 ± 165.63	890.15 ± 131.46	0.03

Values are represented as mean ± SD. Symptom scores on 10-cm visual analogue scale. OCTT: Orocecal transit time; MTL: Motilin; NPY: Neuropeptide Y; VAS: Visual analogue scale.

Table 3 Baseline and after treatment with placebo

Variable	Baseline (n = 28)	Placebo (n = 28)	P value
Cross-sectional area of the proximal stomach (cm2)
200 mL	17.95 ± 3.62	16.56 ± 3.98	0.19
400 mL	29.97 ± 6.35	27.84 ± 5.95	0.09
600 mL	40.78 ± 9.54	34.85 ± 6.61	0.06
800 mL	46.34 ± 9.67	40.86 ± 8.45	0.06
Difficulty in drinking water VAS
200 mL	0.93 ± 0.59	0.96 ± 0.56	0.70
400 mL	1.82 ± 0.54	1.82 ± 0.54	1.00
600 mL	3.36 ± 0.72	3.57 ± 0.94	0.34
800 mL	5.46 ± 0.73	5.57 ± 0.82	0.56
Gastric emptying
5 min	79.55 ± 6.35	78.84 ± 7.47	0.47
10 min	63.89 ± 8.39	64.54 ± 10.29	0.79
OCTT (min)	85.18 ± 19.60	96.61 ± 23.90	0.07
Plasma levels (pg/mL)
MTL	471.75 ± 127.02	473.40 ± 122.75	0.75
Ghrelin	452.50 ± 173.46	442.87 ± 176.79	0.35
NPY	901.17 ± 144.91	890.15 ± 131.46	0.12

Values are represented as mean ± SD. Symptom scores on 10-cm visual analogue scale. OCTT: Orocecal transit time; MTL: Motilin; NPY: Neuropeptide Y; VAS: Visual analogue scale.

Table 4 Baseline and after treatment with amitriptyline

Variable	Baseline (n = 28)	Amitriptyline (n = 28)	P value
Cross-sectional area of the proximal stomach (cm2)
200 mL	17.95 ± 3.62	16.51 ± 3.78	0.22
400 mL	29.97 ± 6.35	27.14 ± 5.71	0.09
600 mL	40.78 ± 9.54	34.11 ± 6.11	0.06
800 mL	46.34 ± 9.67	39.58 ± 7.35	0.06
Difficulty in drinking water VAS
200 mL	0.93 ± 0.59	0.93 ± 0.65	0.99
400 mL	1.82 ± 0.54	1.93 ± 0.46	0.36
600 mL	3.36 ± 0.72	2.98 ± 0.85	0.01
800 mL	5.46 ± 0.73	4.57 ± 0.98	0.001
Gastric emptying
5 min	79.55 ± 6.35	78.40 ± 11.71	0.96
10 min	63.89 ± 8.39	66.72 ± 11.63	0.17
OCTT (min)	85.18 ± 19.60	109.29 ± 29.68	0.001
Plasma levels (pg/mL)
MTL	471.75 ± 127.02	461.88 ± 129.66	0.11
Ghrelin	452.50 ± 173.46	526.87 ± 158.44	0.001
NPY	901.17 ± 144.91	965.64 ± 165.63	0.001

Values are represented as mean ± SD. Symptom scores on 10-cm visual analogue scale. OCTT: Orocecal transit time; MTL: Motilin; NPY: Neuropeptide Y; VAS: Visual analogue scale.

Table 5 Adverse effects of amitriptyline and placebo

Adverse effect	Amitriptyline (n = 28)	Placebo (n = 28)
Sleepiness	10	2
Bitter taste	7	2
Dry mouth	6	3
Tired in early morning	2	1
Dizziness	2	0
Constipation	1	1