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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Date results information initially provided
Type of registration
Retrospectively registered

Titles & IDs
Public title
Sildenafil in Biliary Colic
Scientific title
Sildenafil in relieving pain of biliary colic
A randomized comparative trial
Secondary ID [1] 298795 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Biliary colic 313747 0
Condition category
Condition code
Emergency medicine 312151 312151 0 0
Other emergency care
Oral and Gastrointestinal 312511 312511 0 0
Other diseases of the mouth, teeth, oesophagus, digestive system including liver and colon

Study type
Description of intervention(s) / exposure
sildenafil 25 mg tablet taken orally just once under the direct observation of the investigator, after inclusion of each eligible patient.
Adherence to treatment was monitored for all patients by direct observation and mouth check,
Intervention code [1] 315064 0
Treatment: Drugs
Comparator / control treatment
Ketorolac 20 mg orally, given as two 10 mg tablets swallowed under direct observation of the investigator once just after inclusion of each eligible patients
Control group

Primary outcome [1] 320795 0
Proportions of participants who experience treatment success (defined as reduction of the 4 point verbal rating score (VRS), 60 minutes after dose intake from moderate and severe to mild or none) in both groups.
Timepoint [1] 320795 0
60 minutes after drug intake.
Secondary outcome [1] 372866 0
Change in visual pain analog scale score (VPAS) at 30 minutes and 60 minutes after the dose intake in each treatment group.
Timepoint [1] 372866 0
30 minutes and 60 minutes after drug intake
Secondary outcome [2] 372867 0
Drug emergent adverse drug events assessed by spontaneous subjective complaints or objective signs observed by the investigator or reported by the patient.
Patients will be asked to report any adverse events and specifically to grade the severity of any event such as nausea, vomiting, drowsiness, headache, dizziness, blurring of vision, palpitations, agitation, skin rash, itching and sweating on a 4-point categorical scale. Physiologic parameters: Blood pressure, pulse and respiratory rate will be monitored throughout. starting from just after the drug intake and during the period of 2 days after the intake. These events will be further classified according to seriousness into serious or non-serious.
Timepoint [2] 372867 0
2 days since drug intake

Key inclusion criteria
adult of any sex, aged between 18 and 50 years old experiencing self-described moderate to severe pain in the epigastrium or right upper quadrant of the abdomen that the treating emergency physician suspected to be biliary colic, plus evidence of gallstones, including a known case record of cholelithiasis or immediate abdominal ultrasound examination showing visible stone(s).
Minimum age
18 Years
Maximum age
50 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
pregnancy or breast-feeding; history of coronary artery disease or other cardiac disease with hemodynamic instability or fragility; history of intake of any preparation containing nitrates in any dosage form within the past one week; history of allergy to ketorolac, acetylsalicylic acid (ASA) or another NSAID; and history of peptic ulcer disease, gastrointestinal bleeding, perforation, or inflammatory bowel disease; history or evidence of renal or hepatic dysfunctions..

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation was concealed by opaque envelop method
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Sequence was centrally generated by a computer based block randomization method by an independent statistician
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Exact test by bootstraping 10000 iteration technique

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 21702 0
State/province [1] 21702 0

Funding & Sponsors
Funding source category [1] 303353 0
Self funded/Unfunded
Name [1] 303353 0
Mostafa Yakoot
Address [1] 303353 0
Green Clinic and Research Center, 27 Green Street 21121, alexandria, Egypt.
Country [1] 303353 0
Primary sponsor type
Mostafa Yakoot
Green Clinic and Research Center, 27 Green Street, 21121, Alexandria, Egypt
Secondary sponsor category [1] 303383 0
Name [1] 303383 0
Address [1] 303383 0
Country [1] 303383 0

Ethics approval
Ethics application status
Ethics committee name [1] 303882 0
Green CRC
Ethics committee address [1] 303882 0
27 Green Street, 21121, Alexandria, Egypt
Ethics committee country [1] 303882 0
Date submitted for ethics approval [1] 303882 0
Approval date [1] 303882 0
Ethics approval number [1] 303882 0

Brief summary
Sildenafil, a phosphodiesterase-5 inhibitor, was reported to have a strong inhibitory effect on contraction of visceral smooth muscle of the gallbladder and to significantly decrease the basal biliary pressure of the Sphincter of Oddi.
We hypothesized that a single oral dose of sildenafil given during the acute attack of biliary colic, might counteract the smooth muscular spasm and probably might decrease the pressure inside the ducts and sphincter of Oddi to relieve pain and facilitate release of impacted stones.
We conducted a pilot, randomized, single-blind, comparative clinical study to assess the pain relieving effect of a single-dose of 25 mg oral Sildenafil tablet in comparison with a single oral 20 mg ketorolac dose in adult patients presenting with acute biliary colic.
Methods: Twenty consecutive eligible patients presenting with moderate to severe biliary colic were randomly assigned to receive one Sildenafil 25 mg tablet or two ketorolac 10 mg oral tablets. A four points verbal rating scale (VRS) and 100 mm Visual pain analog scale (VPAS) of pain severity were measured at baseline before treatment then at 30 and 60 minutes after the intake of the oral dose.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 95114 0
Dr Mostafa Yakoot
Address 95114 0
Green Clinic and Research Center, 27 Green Street 21121, Alexandria, Egypt.
Country 95114 0
Phone 95114 0
Fax 95114 0
Email 95114 0
Contact person for public queries
Name 95115 0
Dr Mostafa Yakoot
Address 95115 0
Green Clinic and Research Center, 27 Green Street 21121, Alexandria, Egypt.
Country 95115 0
Phone 95115 0
Fax 95115 0
Email 95115 0
Contact person for scientific queries
Name 95116 0
Dr Mostafa Yakoot
Address 95116 0
Green Clinic and Research Center, 27 Green Street 21121, Alexandria, Egypt.
Country 95116 0
Phone 95116 0
Fax 95116 0
Email 95116 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
Patients opted not to share their data
What supporting documents are/will be available?
No other documents available
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary
Results: Treatment success, defined as reduction of verbal rating scale for pain (VRS), 60 minutes after dose intake from moderate and severe to mild or no pain was 9/10 and 9/10 in sildenafil and ketorolac groups respectively.
Both treatment groups showed significant reduction of VPAS 30 minutes after the dose intake. But the difference was not significant between the two groups. While significantly greater reduction in visual pain analog sores was shown in Sildenafil treated group (83.16%) versus ketorolac group (79.34%) after 60 minutes from dose intake.