Effect of Citalopram on Reflux Episodes in Healthy Volunteers

Effect of Citalopram on Fasting and Postprandial Lower Esophageal Sphincter Function in Healthy Subjects: a Double-blind, Placebo-controlled, Randomized, Cross-over Study

Citalopram is sometimes used in the treatment for gastro-esophageal reflux disease, however, there are no empirical data to support this. The investigators would like to know if citalopram has an effect on the lower esophageal sphincter pressure, transient lower esophageal sphincter relaxations and reflux episodes. The investigators will investigate this by performing high resolution impedance manometry in healthy volunteers before and after a solid meal. This will be compared to placebo, in a cross-over, randomized, double-blind condition.

After placement of a high resolution impedance manometry catheter (transnasally), citalopram will be administered IV over 30 minutes (20 mg in 100ml saline). Thereafter, the investigators will wait for 20 minutes, after which the volunteers will receive 10 wet swallows (5ml saline), to investigate esophageal peristalsis. Thereafter, a standard meal (1000kcal) will be given to the volunteers and recordings will continue for another 2 hours.

After placement of a high resolution impedance manometry catheter (transnasally), placebo (saline 100ml) will be administered IV over 30 minutes. Thereafter, the investigators will wait for 20 minutes, after which the volunteers will receive 10 wet swallows (5ml saline), to investigate esophageal peristalsis. Thereafter, a standard meal (1000kcal) will be given to the volunteers and recordings will continue for another 2 hours.

Citalopram HCl IV 20 mg in 100 ml saline will be infused IV over the course of 30 minutes. Volunteers will receive a standard meal, and recordings using high resolution impedance manometry, will be continued for 2 hours.

Placebo (100 ml saline IV) will be infused IV over the course of 30 minutes. Volunteers will receive a standard meal, and recordings using high resolution impedance manometry, will be continued for 2 hours.

The investigators will measure lower esophageal sphincter pressure after a meal between placebo and citalopram, using a high resolution impedance manometry system. LES pressures will be measured in the first hour postprandial and will be compared (preprandial vs postprandial hour 1).

LES pressure will be measured for 4 times (a 5 sec time window) per hour. The average of the first hour will be taken as the LES pressure for the first hour postprandially.

The investigators will measure the number of reflux episodes after a meal between placebo and citalopram, using a high resolution impedance manometry system.

The number of reflux episodes will be counted in a 3 hour time period, to have 1 number of reflux episodes.

The investigators will measure the number of transient lower esophageal sphincter relaxations after a meal between placebo and citalopram, using a high resolution impedance manometry system.

Inclusion Criteria: between 18 and 65 years Exclusion Criteria: history of upper GI symptoms history of upper GI surgery psychological disorders any drug history use of medication altering GI motility nursing and pregnant woman