Morphine Consumption in Joint Replacement Patients, With or Without Gabapentin Treatment

McMaster University

Status: Completed

Conditions: Total Knee Replacement; Post Operative Pain

Treatments: Drug: Gabapentin; Drug: Placebo

Study type: Interventional

Funder types: Other

Identifiers

NCT01307202

07-215-TKR

Details and patient eligibility

About

Total knee arthroplasty is amongst the most painful procedures postoperatively, and pain management can be a challenge. Different measures have been introduced to manage severe postoperative pain int hese patients. Previous studies have investigated gabapentin in acute postoperative pain and demonstrated reducted pain, postoperative morphine consumption, morphine related side effects, and postoperative pain scores. To date, this analgesia adjunct has yet to be investigated in total joint arthroplasty patients.

Full description

The study was submitted to Health Canada and received the letter of no objection. A randomized, double-blind, placebo-controlled study. The randomization scheme will be prepared and will be done by the pharmacy department at McMaster University. Ninety patients undergoing primary knee arthroplasty will be recruited from the preoperative clinic. Forty-five patients in each population will be allocated to a gabapentin group and the other forty-five to a placebo group.

Enrollment: 101 patients

Sex: All

Ages: 19 to 90 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• participants aged 19-90
• elective single joint, primary total knee arthroplasty
• use of PCA with morphine for postoperative pain control has been discussed and agreed upon between patient and anesthetist

Exclusion criteria

• bilateral total knee arthroplasty
• revision knee arthroplasty
• underlying disease of epilepsy, seizure, or chronic pain syndrome
• active gastrointestinal bleeding within the last 6 months
• history of non-steroidal anti-inflammatory drug (NSAID) induced asthma
• known or suspected history of drug or alcohol abuse
• participant currently takes gabapentin or pregabalin for any reason
• participant currently takes pain medication that is more potency than codeine or oxycodone (morphine, hydromorphone, meperidine, methadone, fentanyl, including any long acting narcotics)
• known allergy to study medications: gabapentin, morphine, NSAID, acetaminophen
• unable to tolerate morphine
• liver impairments
• kidney impairment or calculated creatinine clearance by Cockcroft-Gault formula is <=60ml/min
• pregnancy or breast-feeding
• participant currently receives associated worker's compensation benefits (WSIB)
• participant unable or unwilling to give written or informed consent
• unable to use PCA

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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101 participants in 2 patient groups, including a placebo group

Gabapentin

Experimental group

Description:

Gabapentin 600 mg will be given per oral two hours preoperatively and 200 mg three times daily after surgery (600 mg/day).

Treatment:

Drug: Gabapentin

Placebo

Placebo Comparator group

Description:

Placebo will match the the gabapentin pill and will be given orally.

Treatment:

Drug: Placebo