Postoperative Pain
Conditions
Keywords
Gabapentin, PRK, pain
Brief summary
The purpose of this study is to determine the effectiveness of an oral medication called gabapentin in reducing pain after Photorefractive Keratectomy (PRK) eye surgery and to assess the frequency of use of rescue medication interventions, defined as non-steroidal anti-inflammatory (NSAID) eye drops and oral narcotic medication.
Interventions
DRUGGabapentin
Gabapentin 300 mg taken by mouth thrice daily for 7 days
DRUGplacebo
placebo (sugar pill) taken by mouth thrice daily for 7 days
Sponsors
Walter Reed Army Medical Center
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
21 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Ability to understand and provide informed consent to participate in this study and complete follow-up visits. * Planned Photorefractive keratectomy (PRK) at the WRAMC Center for Refractive Surgery. * Male or female, of any race, and at least 21 years old at the time of the pre-operative examination, and have signed an informed consent. The lower age limit of 21 years is intended to ensure documentation of refractive stability. * Access to transportation to meet follow-up requirements.
Exclusion criteria
* Any reason to be excluded for PRK. * Female subjects who are pregnant, breast feeding or intend to become pregnant during the study. Female subjects will be given a urine pregnancy test prior to participating in the study to rule out pregnancy. \[Pregnancy and breastfeeding are contraindications to refractive surgery in general, including PRK, whether participating in this study or not\]. * Patients with known allergy, sensitivity or inappropriate responsiveness to Gabapentin or any of the medications used in the post-operative course. * Patients with known depressed renal function. * Any physical or mental impairment that would preclude participation in any of the examinations.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Level of Pain | 2 hours postoperatively | level of pain was measured using the Visual Analog Scale (VAS)ranging from 0 (none) to 10 (worst possible pain) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Occurence of Use of Rescue Medication | 2 hours to 4 days postoperatively | Occurrence of use of either ketorolac eyedrops(Acular) or oxycodone-acetaminophen tablet (Percocet), or both was measured |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Gabapentin Gabapentin 300mg taken by mouth thrice daily for 7 days | 48 |
| Placebo placebo (sugar pill) taken by mouth thrice daily for 7 days | 46 |
| Total | 94 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | decided to undergo LASIK instead of PRK | 2 | 1 |
| Overall Study | did not pick up medications | 1 | 1 |
| Overall Study | discarded study pills | 0 | 1 |
| Overall Study | ineligible based on entry criteria | 2 | 3 |
| Overall Study | Withdrawal by Subject | 0 | 1 |
Baseline characteristics
| Characteristic | Placebo | Gabapentin | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 46 Participants | 48 Participants | 94 Participants |
| Age, Continuous | 33.2 years STANDARD_DEVIATION 7.9 | 30.7 years STANDARD_DEVIATION 8 | 31.9 years STANDARD_DEVIATION 8 |
| Region of Enrollment United States | 46 participants | 48 participants | 94 participants |
| Sex: Female, Male Female | 7 Participants | 6 Participants | 13 Participants |
| Sex: Female, Male Male | 39 Participants | 42 Participants | 81 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 53 | 0 / 53 |
| serious Total, serious adverse events | 0 / 53 | 0 / 53 |
Outcome results
Primary
Level of Pain
level of pain was measured using the Visual Analog Scale (VAS)ranging from 0 (none) to 10 (worst possible pain)
Time frame: 2 hours postoperatively
Population: 11 patients who had alcohol-assisted PRK were removed from data analysis; 1 patient was disenrolled due to nausea secondary to oxycodone-acetaminophen (Percocet) intake
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Gabapentin | Level of Pain | 3.85 units on a scale | Standard Deviation 2.05 |
| Placebo | Level of Pain | 4.09 units on a scale | Standard Deviation 2.38 |
Primary
Level of Pain
level of pain was measured using the Visual Analog Scale (VAS)ranging from 0 (none) to 10 (worst possible pain)
Time frame: day 1 postoperatively
Population: 11 patients who had alcohol-assisted PRK were removed from data analysis; 1 patient was disenrolled due to nausea secondary to oxycodone-acetaminophen (Percocet) intake
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Gabapentin | Level of Pain | 3.00 units on a scale | Standard Deviation 2.01 |
| Placebo | Level of Pain | 4.00 units on a scale | Standard Deviation 1.97 |
Primary
Level of Pain
level of pain was measured using the Visual Analog Scale (VAS)ranging from 0 (none) to 10 (worst possible pain)
Time frame: 3 days postoperatively
Population: 11 patients who had alcohol-assisted PRK were removed from data analysis; 1 patient was disenrolled due to nausea secondary to oxycodone-acetaminophen (Percocet) intake
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Gabapentin | Level of Pain | 2.09 units on a scale | Standard Deviation 1.57 |
| Placebo | Level of Pain | 2.58 units on a scale | Standard Deviation 2.08 |
Primary
Level of Pain
level of pain was measured using the Visual Analog Scale (VAS)ranging from 0 (none) to 10 (worst possible pain)
Time frame: 4 days postoperatively
Population: 11 patients who had alcohol-assisted PRK were removed from data analysis; 1 patient was disenrolled due to nausea secondary to oxycodone-acetaminophen (Percocet) intake
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Gabapentin | Level of Pain | 1.30 units on a scale | Standard Deviation 1.16 |
| Placebo | Level of Pain | 1.86 units on a scale | Standard Deviation 1.96 |
Secondary
Occurence of Use of Rescue Medication
Occurrence of use of either ketorolac eyedrops(Acular) or oxycodone-acetaminophen tablet (Percocet), or both was measured
Time frame: 2 hours to 4 days postoperatively
Population: 11 patients who had alcohol-assisted PRK were removed from data analysis; 1 patient was disenrolled due to nausea secondary to oxycodone-acetaminophen (Percocet) intake
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Gabapentin | Occurence of Use of Rescue Medication | 7.54 # of times rescue meds were used | Standard Deviation 3.45 |
| Placebo | Occurence of Use of Rescue Medication | 7.15 # of times rescue meds were used | Standard Deviation 3.9 |