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Diphenhydramine as an Adjunctive Sedative in Patients on Chronic Opioids

Use of Diphenhydramine as an Adjunctive Sedative for Colonoscopy in Patients Chronically on Opioids

Status
Completed
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01967433
Enrollment
120
Registered
2013-10-22
Start date
2013-12-31
Completion date
2018-07-31
Last updated
2020-03-11

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Adjunct Anesthesia Medication, Colonoscopy

Keywords

Fentanyl, Midazolam, Sedation, Patient tolerance, Duration of colonoscopy

Brief summary

To access the efficacy of adding diphenhydramine as adjunct to improve sedation and to reduce the amount of standard sedatives used during colonoscopy in patients on chronic opioids.

Detailed description

Specific Aims: The primary aim of our study is to determine if addition of Diphenhydramine to Fentanyl and Midazolam will decrease the dose of Fentanyl and Midazolam used during colonoscopy in individuals on chronic opioids. Secondarily we will be looking at quality of sedation, duration of colonoscopy, time to reach cecum and adverse effects (hypoxia defined as O2 saturation less than 89% lasting for more than 30 seconds, hypotension defined as systolic BP less than 90 mmhg and use of reversal agents i.e Naloxone or Flumazenil). Day of Procedure: After consent is obtained the medical records of the patients will be reviewed and demographic information, co-morbidities, current medication will be extracted and recorded. On the day of colonoscopy Alcohol use disorder inventory (AUDIT) will be used to screen for alcohol abuse. AUDIT was developed by World Health Organization and has been validated over a period of 2 decades. It consist of 10 questions, each question is scored 0-4 on the basis of subjects alcohol use. It takes about 2-4 minutes to complete. A score 10 or greater is highly specific or alcohol use. Subjects will be checked in and prepared according to routine protocols of the VA medical center. Participants will be randomly assigned to receive either 50 mg of diphenhydramine or 10 ml of 0.9% sodium chloride. On the day of colonoscopy randomization will be performed by an independent investigator who is a pharmacist at VA medical center using the website http://www.randomization.com. She will also prepare and dispense medication. Each endoscopy team will consist of an attending gastroenterologist, gastroenterology fellow and two nurses. Medications will be administered by one of the nurses under the direct supervision of the physician. At the start of procedure baseline vitals will be recorded as per our unit's policy. Research medication will be administered 3 minutes prior to administration of other medications. Neither the patient nor the medical staff including the endoscopist will be aware of the contents of the vial. Conscious sedation will be achieved using a combination of intravenous midazolam and fentanyl as standard sedative. Rarely, additional diphenhydramine will be given, on the basis of the judgment of the endoscopist. During the procedure vital signs including oxygen saturation will be monitored at 3-5 minute interval. Procedure related complications, including hypotension, desaturation and cardiac arrhythmia will be managed according to our endoscopy unit policy and protocols. Following the procedure, the nurse and the fellow or the attending will individually rate the quality if sedation on a ten-point Likert scale. Qualitative assessment will also be made (Under-sedated, adequately sedated, or over-sedated). Recovery time will be recorded. Day Following the Colonoscopy Twenty-four hour discharge a follow up call will be made and the patients will be asked to evaluate the level of sedation on a 10-point scale (1, inadequate; 10 completely without discomfort); pain (1, no pain; 10 severe pain), and amnesia (10, no memory of the procedure; 1 complete memory).

Interventions

DRUGDiphenhydramine
DRUGPlacebo

Sponsors

University of Oklahoma
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
SUPPORTIVE_CARE
Masking
TRIPLE (Subject, Caregiver, Investigator)

Eligibility

Sex/Gender
ALL
Age
18 Years to 64 Years
Healthy volunteers
No

Inclusion criteria

* Patients aged 18-64 years undergoing screening, surveillance, diagnostic and therapeutic colonoscopy * Patient on chronic opioids defined as at least 5 mg of morphine or its equivalent at least 3 days per week for more than 3 months

Exclusion criteria

* Inability to execute informed consent * Allergy to Diphenhydramine, fentanyl or midazolam * Known or suspected pregnancy * Endoscopic procedure without sedation * Patient scheduled to have other endoscopic procedures on the same day * Prior alimentary tract surgery * Severe cardiopulmonary disease (ASA IV) * Monoamine Oxidase Inhibitors (MOI) use within 2 weeks of procedure

Design outcomes

Primary

MeasureTime frameDescription
Dosage of FentanylFrom induction (first dose of sedative) to end of procedureModerate sedation (using the American Society of Anesthesiologists definition of maintaining purposeful response to verbal or tactile stimulation, adequate ventilation requiring no airway protection, and maintenance of cardiovascular function) was then achieved using incremental doses of the combination of intravenous midazolam (1 mg) and fentanyl (25 μg) given every 2 to 3 minutes. To minimize any crossover, additional diphenhydramine was not permitted.

Secondary

MeasureTime frameDescription
Duration of ProcedureTime from induction (first dose of sedative) to dischargeInduction period (time from first dose of fentanyl to scope insertion), procedural time (time from scope insertion to scope out), and recovery time (time from scope out to discharge) were recorded by the nursing staff in their standard documentation.
Number of Participants With Adverse EventsFrom induction (first dose of sedative) to dischargeFollowing adverse events will be recorded: (1)Hypoxia defined as O2 saturation less than 89% lasting for more than 30 seconds, (2)hypotension defined as systolic BP less than 90 mmhg and (3)use of reversal agents i.e Naloxone or Flumazenil
Quality of SedationDuring the colonoscopy and 24 hours after dischargeQuality of sedation will be accessed by the nurse and the physician at the end of procedure. Name: 10 point visual analogue scale Minimum score: 1 (worse) Maximum score: 10 (better)
Dosage of MidazolamFrom induction (first dose of sedative) to end of procedureModerate sedation (using the American Society of Anesthesiologists definition of maintaining purposeful response to verbal or tactile stimulation, adequate ventilation requiring no airway protection, and maintenance of cardiovascular function) was then achieved using incremental doses of the combination of intravenous midazolam (1 mg) and fentanyl (25 μg) given every 2 to 3 minutes. To minimize any crossover, additional diphenhydramine was not permitted.
24 Hour Follow up Amnesia ScoreAt about 24 after the procedurePatient were also asked to rate amnesia on a 10 point scale 24 after discharge. minimum= 0 (worse) maximum =10 (better)
24 Hour Follow up Pain ScoreAbout 24 hours after the procedureAt 24 hr follow up patients were asked to rate the level of pain during the procedure using 10 point scale. 10 point visual analogue scale minimum= 0 (better) maximum =10 (worse)

Countries

United States

Participant flow

Participants by arm

ArmCount
Diphenhydramine
Diphenhydramine 50 mg IV 3 minutes prior to administration of other sedatives
61
Placebo
0.9% sodium chloride 10 ml IV 3 minuted prior to administration of other sedatives
58
Total119

Baseline characteristics

CharacteristicDiphenhydraminePlaceboTotal
Age, Continuous60.7 years
STANDARD_DEVIATION 9.3
60.1 years
STANDARD_DEVIATION 9.7
60.37 years
STANDARD_DEVIATION 9
Race/Ethnicity, Customized
Race
Others
16 Participants12 Participants28 Participants
Race/Ethnicity, Customized
Race
White
45 Participants46 Participants91 Participants
Region of Enrollment
United States
61 participants58 participants119 participants
Sex: Female, Male
Female
4 Participants2 Participants6 Participants
Sex: Female, Male
Male
57 Participants56 Participants113 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 610 / 58
other
Total, other adverse events
17 / 6125 / 58
serious
Total, serious adverse events
0 / 610 / 58

Outcome results

Primary

Dosage of Fentanyl

Moderate sedation (using the American Society of Anesthesiologists definition of maintaining purposeful response to verbal or tactile stimulation, adequate ventilation requiring no airway protection, and maintenance of cardiovascular function) was then achieved using incremental doses of the combination of intravenous midazolam (1 mg) and fentanyl (25 μg) given every 2 to 3 minutes. To minimize any crossover, additional diphenhydramine was not permitted.

Time frame: From induction (first dose of sedative) to end of procedure

ArmMeasureValue (MEAN)Dispersion
DiphenhydramineDosage of Fentanyl125.4 (μg)Standard Deviation 56.2
PlaceboDosage of Fentanyl126.9 (μg)Standard Deviation 53.5
Secondary

24 Hour Follow up Amnesia Score

Patient were also asked to rate amnesia on a 10 point scale 24 after discharge. minimum= 0 (worse) maximum =10 (better)

Time frame: At about 24 after the procedure

ArmMeasureValue (MEAN)Dispersion
Diphenhydramine24 Hour Follow up Amnesia Score7.8 score on a 10 point point scaleStandard Deviation 3.4
Placebo24 Hour Follow up Amnesia Score6.5 score on a 10 point point scaleStandard Deviation 3.8
Secondary

24 Hour Follow up Pain Score

At 24 hr follow up patients were asked to rate the level of pain during the procedure using 10 point scale. 10 point visual analogue scale minimum= 0 (better) maximum =10 (worse)

Time frame: About 24 hours after the procedure

ArmMeasureValue (MEAN)Dispersion
Diphenhydramine24 Hour Follow up Pain Score2.0 score on a scaleStandard Deviation 2.17
Placebo24 Hour Follow up Pain Score3.09 score on a scaleStandard Deviation 3.95
Secondary

Dosage of Midazolam

Moderate sedation (using the American Society of Anesthesiologists definition of maintaining purposeful response to verbal or tactile stimulation, adequate ventilation requiring no airway protection, and maintenance of cardiovascular function) was then achieved using incremental doses of the combination of intravenous midazolam (1 mg) and fentanyl (25 μg) given every 2 to 3 minutes. To minimize any crossover, additional diphenhydramine was not permitted.

Time frame: From induction (first dose of sedative) to end of procedure

ArmMeasureValue (MEAN)Dispersion
DiphenhydramineDosage of Midazolam4.9 mgStandard Deviation 2.1
PlaceboDosage of Midazolam5.0 mgStandard Deviation 1.9
Secondary

Duration of Procedure

Induction period (time from first dose of fentanyl to scope insertion), procedural time (time from scope insertion to scope out), and recovery time (time from scope out to discharge) were recorded by the nursing staff in their standard documentation.

Time frame: Time from induction (first dose of sedative) to discharge

ArmMeasureGroupValue (MEAN)Dispersion
DiphenhydramineDuration of ProcedureProcedure time34.8 minutesStandard Deviation 19.5
DiphenhydramineDuration of ProcedureRecovery34.4 minutesStandard Deviation 9.2
DiphenhydramineDuration of ProcedureInduction6.4 minutesStandard Deviation 3.2
PlaceboDuration of ProcedureProcedure time34.7 minutesStandard Deviation 17.8
PlaceboDuration of ProcedureRecovery32.4 minutesStandard Deviation 5.9
PlaceboDuration of ProcedureInduction6.3 minutesStandard Deviation 2.8
Secondary

Number of Participants With Adverse Events

Following adverse events will be recorded: (1)Hypoxia defined as O2 saturation less than 89% lasting for more than 30 seconds, (2)hypotension defined as systolic BP less than 90 mmhg and (3)use of reversal agents i.e Naloxone or Flumazenil

Time frame: From induction (first dose of sedative) to discharge

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
DiphenhydramineNumber of Participants With Adverse EventsHypotension12 Participants
DiphenhydramineNumber of Participants With Adverse EventsArrhythmia0 Participants
DiphenhydramineNumber of Participants With Adverse EventsDesaturation0 Participants
DiphenhydramineNumber of Participants With Adverse EventsReversal agent use0 Participants
DiphenhydramineNumber of Participants With Adverse EventsHypertension5 Participants
DiphenhydramineNumber of Participants With Adverse EventsTachypnea0 Participants
DiphenhydramineNumber of Participants With Adverse EventsApnea0 Participants
PlaceboNumber of Participants With Adverse EventsTachypnea0 Participants
PlaceboNumber of Participants With Adverse EventsHypotension22 Participants
PlaceboNumber of Participants With Adverse EventsHypertension3 Participants
PlaceboNumber of Participants With Adverse EventsDesaturation0 Participants
PlaceboNumber of Participants With Adverse EventsApnea0 Participants
PlaceboNumber of Participants With Adverse EventsArrhythmia0 Participants
PlaceboNumber of Participants With Adverse EventsReversal agent use0 Participants
Secondary

Quality of Sedation

Quality of sedation will be accessed by the nurse and the physician at the end of procedure. Name: 10 point visual analogue scale Minimum score: 1 (worse) Maximum score: 10 (better)

Time frame: During the colonoscopy and 24 hours after discharge

ArmMeasureGroupValue (MEAN)Dispersion
DiphenhydramineQuality of SedationPhysician rating6.2 score on a scaleStandard Deviation 1.1
DiphenhydramineQuality of SedationNurse rating5.6 score on a scaleStandard Deviation 1.5
PlaceboQuality of SedationPhysician rating5.3 score on a scaleStandard Deviation 1.2
PlaceboQuality of SedationNurse rating5.1 score on a scaleStandard Deviation 1.4

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026