Postoperative Pain | Comparison of Oral Gabapentin and Pregabalin in Postoperative Pain Control After Photorefractive Keratectomy

Postoperative Pain research study

What is the primary objective of this study?

Purpose: To compare the efficacy of oral gabapentin and its newer analogue pregabalin in postoperative pain control after photorefractive keratectomy (PRK). Methods: One hundred and four patients who meet the inclusion criteria undergoing PRK in one or both eyes will be randomized into one of two treatment groups. Those in group A will be treated with gabapentin, and those in group B will be treated with pregabalin to control postoperative PRK pain. Patients in both groups will begin treatment two hours prior to surgery in order to achieve therapeutic blood levels of each medication. After surgery the patients will assess their pain level using the visual analogue scale (VAS) at different intervals of time - one hour after surgery, the evening of the surgery, and three times each day for three subsequent days. Patients will also daily assess their level of somnolence using the Epworth Sleepiness Scale (ESS) and record the presence of dizziness for the same amount of time. On the fourth day they will return to clinic for a postoperative appointment. At that time the pain, sleepiness, and dizziness assessment scales will be collected and analyzed. The patients will return one month later to further assess long-term pain and healing after PRK. Results: Both gabapentin and pregabalin have been shown in previous studies to treat postoperative pain effectively. The effects of gabapentin 300 mg TID for 3 days versus pregabalin 50 mg TID for 3 days on decreasing overall postoperative pain following PRK will be presented. Conclusion: The effectiveness of the two different treatment medications will be analyzed, and the conclusion will be based on the results.

Who is eligible to participate?

Inclusion Criteria: - 18 years of age or older - Undergoing PRK in at least one eye Exclusion Criteria: - Serious medical problems within the last 6 months including myocardial infarction (heart attack), congestive heart failure, stroke, deep vein thrombosis, pulmonary embolism, and other conditions, etc. - Serious kidney disease as evidenced by the need for dialysis or kidney transplant. - History of seizure or other neurologic disorders. - Patients intending to become pregnant or who are pregnant or nursing over the projected course of treatment. - Currently taking gabapentin or pregabalin for other medical purposes. - Known allergic reaction to gabapentin or pregabalin from previous use. - Plans to move out of the area within 8 weeks after the surgery.

Which medical condition, disease, disorder, syndrome, illness, or injury is researched?

Postoperative Pain

Study Interventions

Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.

Drug:GabapentinGabapentin - 300 mg three times a day starting two hours prior to surgery and will continue for a total of four days

Drug:pregabalin50 mg PO TID

Study Arms

Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.



Study Status


Start Date: November 2009

Completed Date: April 2013

Phase: N/A

Type: Interventional


Primary Outcome: Decreased Overall Pain Score as Measured by the Visual Analogue Scale

Secondary Outcome:

Study sponsors, principal investigator, and references

Principal Investigator: Julio Narvaez, MD

Lead Sponsor: Loma Linda University


More information:

Shortt AJ, Allan BD. Photorefractive keratectomy (PRK) versus laser-assisted in-situ keratomileusis (LASIK) for myopia. Cochrane Database Syst Rev. 2006 Apr 19;(2):CD005135. Review. Update in: Cochrane Database Syst Rev. 2013;1:CD005135.

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