Oral Gabapentin Versus Placebo for Treatment of Postoperative Pain Following Photorefractive Keratectomy

Oral Gabapentin Versus Placebo for Treatment of Postoperative Pain Following Photorefractive Keratectomy: A Randomized, Double-masked, Single Center, Placebo-controlled Clinical Trial

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.

Study Overview

• Status: Completed
• Conditions: Postoperative Pain
• Intervention / Treatment: Drug: Gabapentin; Drug: placebo

• Study Type: Interventional
• Enrollment (Actual): 106
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • District of Columbia
    • Washington, District of Columbia, United States, 20307
      • Walter Reed Army Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: placebo	Drug: placebo; placebo (sugar pill) taken by mouth thrice daily for 7 days
Active Comparator: Gabapentin; oral medication	Drug: Gabapentin; Gabapentin 300 mg taken by mouth thrice daily for 7 days

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Level of Pain	level of pain was measured using the Visual Analog Scale (VAS)ranging from 0 (none) to 10 (worst possible pain)	2 hours postoperatively
Level of Pain	level of pain was measured using the Visual Analog Scale (VAS)ranging from 0 (none) to 10 (worst possible pain)	day 1 postoperatively
Level of Pain	level of pain was measured using the Visual Analog Scale (VAS)ranging from 0 (none) to 10 (worst possible pain)	3 days postoperatively
Level of Pain	level of pain was measured using the Visual Analog Scale (VAS)ranging from 0 (none) to 10 (worst possible pain)	4 days postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Occurence of Use of Rescue Medication	Occurrence of use of either ketorolac eyedrops(Acular) or oxycodone-acetaminophen tablet (Percocet), or both was measured	2 hours to 4 days postoperatively

Collaborators and Investigators

• Sponsor: Walter Reed Army Medical Center

Study record dates

Study Major Dates

• Study Start: July 1, 2008
• Primary Completion (Actual): July 1, 2009
• Study Completion (Actual): July 1, 2009

Study Registration Dates

• First Submitted: November 18, 2008
• First Submitted That Met QC Criteria: November 18, 2008
• First Posted (Estimate): November 19, 2008

Study Record Updates

• Last Update Posted (Estimate): July 16, 2014
• Last Update Submitted That Met QC Criteria: July 10, 2014
• Last Verified: July 1, 2014

More Information

Terms related to this study

• Keywords: pain; Gabapentin; PRK
• Additional Relevant MeSH Terms: Pathologic Processes; Postoperative Complications; Pain; Neurologic Manifestations; Pain, Postoperative; Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Excitatory Amino Acid Antagonists; Excitatory Amino Acid Agents; Tranquilizing Agents; Psychotropic Drugs; Anti-Anxiety Agents; Anticonvulsants; Antimanic Agents; Gabapentin
• Other Study ID Numbers: WRAMC WU# 08-6960