The Median Effective Dose (ED50) of Paracetamol and Morphine : A Study of Interaction Study

Not Applicable

Completed

• Conditions: Postoperative Pain
• Interventions: Drug: Morphine; Drug: Paracetamol- Morphine; Drug: Paracetamol

• Registration Number: NCT01366313
• Lead Sponsor: Procare Riaya Hospital

Brief Summary

The aim of our study is to define the median effective analgesic doses (ED50) of paracetamol, morphine, and their combination and determination the nature of their interaction administered IV for postoperative pain after moderate painful surgery using up-and-down and isobolographic methods.

Detailed Description

Ninety patients scheduled to undergo moderately painful surgery were included in one of three groups. Determination of median effective (ED50) doses was performed by the Dixon and Mood up-and-down method. Initial doses were 1.5g and 5mg, with dose adjustment intervals of 0.5g and 1 mg, in the paracetamol and morphine groups, respectively. The initial doses of paracetamol and morphine were 1.5g and 3mg, respectively in the paracetamol-morphine combination group with dose adjustment intervals of 0.25g for paracetamol and 0.5mg for morphine. Analgesic efficacy was defined as a decrease to less than 3 on a 0-10 numeric pain scale, 45 min after the beginning of drug administration. Isobolographic analysis was used to define the nature of their interaction.

Study Timeline

• Study Start: 2007-09
• Status Verified: 2011-01
• Primary Completion: 2011-03
• Study Completion: 2011-03
• Study First Submitted: 2011-06-02
• Study First Submitted QC: 2011-06-03
• Study First Posted: 2011-06-06
• Last Update Submitted: 2012-12-07
• Last Update Posted: 2012-12-10

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 90

Inclusion Criteria

1. ASA physical status І or ІІ
2. Moderately painful surgery patients
3. postoperative pain more than 3 on a numerical pain score (NPS) -

Exclusion Criteria

1. contraindication to the use of paracetamol and morphine
2. Pregnancy
3. age younger than 18 yr
4. patient weight less 65kg
5. intra-operative regional anesthesia,
6. intra-operative administration of analgesics other than fentanyl,
7. postoperative pain less than 3 on a numerical pain score (NPS)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Morphine	Morphine	Initial doses of morphine was 5mg, with dose adjustment intervals of 1 mg .
Paracetamol-morphine	Paracetamol- Morphine	The initial doses of paracetamol and morphine were 1.5g and 3mg, respectively in the paracetamol-morphine combination group with dose adjustment intervals of 0.25g for paracetamol and 0.5mg for morphine.
Paracetamol	Paracetamol	initial doses was 1.5g g, with dose adjustment intervals of 0.5g . with maximum dose 2.5 g as an only starting dose / 24 h

Primary Outcome Measures

Name	Time	Method
ED50s of Paracetamol, morphine and their combination	participants will be followed for the duration of hospital stay, an expected average of 8 weeks	the aim of our study is to define the median effective analgesic doses (ED50s) of paracetamol, morphine, and their combination to determine the nature of their interaction administered IV for postoperative moderately painful surgery using the Dixon and Mood up-and-down method and isobolographic analysis.

Secondary Outcome Measures

Name	Time	Method
Paracetamol-Morphine interaction nature	participants will be followed for the duration of hospital stay, an expected average of 8 weeks	the aim of our study is to define the median effective analgesic doses (ED50s) of paracetamol, morphine, and their combination to determine the nature of their interaction administered IV for postoperative moderately painful surgery using the Dixon and Mood up-and-down method and isobolographic analysis.

Trial Locations

Locations (1)

Procare Riaya Hospital; 🇸🇦 Al Khobar, Estern, Saudi Arabia