Related Experiment Video
Updated: Jun 4, 2026
Bladder Smooth Muscle Strip Contractility as a Method to Evaluate Lower Urinary Tract Pharmacology
Published on: August 18, 2014
Effect of caffeine on bladder function in patients with overactive bladder symptoms
Supatra Lohsiriwat1, Muthita Hirunsai, Bansithi Chaiyaprasithi
1Department of Physiology, Division of Urology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Objectives:
To evaluate the effect of caffeine at the dose of 4.5 mg/kg on bladder function in overactive bladder (OAB) adults.
Materials And Methods:
Nine women and three men aged 21-40 years with OAB symptoms were included. Each subject drank 8 ml/kg of water with and without caffeine at two separate sessions. Cystometry and uroflowmetry were performed 30 minutes after each drink. The effects of caffeine on urodynamic parameters were compared.
Results:
After caffeine ingestion, the mean volume at bladder filling phase decreased at first desire to void and normal desire to void (P<0.05), compared to the mean volume after taking water (control) drink. The mean volume at strong desire to void, urgency and maximum cystometric capacity also tended to decrease. No change in the detrusor pressure at filling phase was found. At voiding phase, the maximal flow rate, average flow rate and voided volume were increased (P<0.05). The urine flow time and time to maximal flow rate were not changed.
Conclusion:
Caffeine at 4.5 mg/kg caused diuresis and decreased the threshold of sensation at filling phase, with an increase in flow rate and voided volume. So, caffeine can promote early urgency and frequency of urination. Individuals with lower urinary tract symptom should avoid or be cautious in consuming caffeine containing foodstuffs.
Related Concept Videos
01:19Urodynamic Studies: Uroflowmetry
01:22Imaging Studies VI: Voiding Cystourethrography and Cystography
01:23Urinary Bladder
In males, the bladder is situated in front of the rectum, while in females, it is positioned anterior to the vagina and uterus. The bladder floor contains an inverted triangular area called the trigone, defined by the two ureteric...
01:17Urinary Tract Infection IV: Nursing Management
01:28Urologic Endoscopic Procedure: Cystoscopic Examination
01:26The Micturition Reflex
The process begins with bladder filling, where the bladder wall stretches as urine accumulates. This stretching activates the urine storage reflex, mediated by the sacral spinal segments and the pontine storage center. Efferent sympathetic impulses stimulate the detrusor muscle to relax and the internal urethral sphincter to contract, facilitating urine...