Assessment of the Effect of Clonidine for Cataract Surgery

Federal University of São Paulo

Status and phase: Unknown; Phase 2

Conditions: Arrythmia; Pain

Treatments: Drug: Clonidine; Drug: placebo

Study type: Interventional

Funder types: Other

Identifiers

NCT01677351

CEP 0609/01-clonidine

Details and patient eligibility

About

Clonidine, an agonist for alfa2 pre-synaptic, has been shown to be an effective adjuvant therapy for acute postoperative pain and has been shown an effect in sedative, intra-ocular and blood pressure and arrhythmias.The objective of this study is evaluating the analgesic effect of clonidine and its repercussion on arterial and intraocular pressure and arrhythmias for cataract surgery.

Full description

After approved by the Ethical Committee and signed informed consent, 40 patients aged from 40 until 80 years undergoing cataract extraction will be randomized in two groups. Exclusion criteria will be myocardial ischemia, psychiatric disease, chronic pain, drugs dependency, chronic use of beta-blockage channel drugs. Group 2, patients will receive a single dose of 4mcg.kg-1 of clonidin2, 20 minutes before the surgical incision; group 1, patients will receive a sterile saline solution dose. Pain intensity will be assessed with the numeric rating scale. The antiarrythmic effect will be assessed with the continuous measure by Holter. The number of patients was calculated by Instat Graph® program. To detect difference in pain intensity of 3 between the groups by NRS, with 95% of power (estimated SD= 2.0), when the alpha level is set at 0.05, the sample should be of 20. Statistical analyses will be performed with parametric and nonparametric tests, considering the variety studied. The statistical program that will be utilized is Instat Graph®.

Enrollment: 40 estimated patients

Sex: All

Ages: 40 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• cataract surgery
• topical anesthesia

Exclusion criteria

• myocardial ischemia
• psychiatric disease
• chronic pain
• drugs dependency
• use of beta-blockage channel drugs

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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40 participants in 2 patient groups, including a placebo group

group 2: clonidine 4mcg.kg

Active Comparator group

Description:

this group (group 2) will receive 4mcg.kg-1 of clonidine 20 minutes before surgery.

Treatment:

Drug: Clonidine

Group 1: sterile saline solution

Placebo Comparator group

Description:

this group (Group 1) will receive a sample injection of sterile saline solution 20 minutes before surgery

Treatment:

Drug: placebo