Imipramine and Pregabalin Combination in Painful Polyneuropathy

Odense University Hospital

Status and phase: Unknown; Phase 4

Conditions: Polyneuropathy

Treatments: Drug: Placebo; Drug: Imipramine, pregabalin; Drug: Imipramine; Drug: Pregabalin

Study type: Interventional

Funder types: Other; Industry

Identifiers

NCT01047488

tcapgbcomb1

2009-013642-80 (EudraCT Number)

Details and patient eligibility

About

Polyneuropathy of different etiologies is often associated with pain and the standard treatment for this type of pain is gabapentinoids or antidepressants. The hypothesis of this study is that the combination of the gabapentinoid pregabalin and the antidepressant imipramine will provide better pain relief than the single compounds alone.

This is a randomized, placebo-controlled, double-blind, 4-way, cross-over trial of pregabalin 300 mg/day, imipramine 75 mg/day and their combination versus placebo. The study will include 60 patients and the treatment outcome will be pain intensity as measured by numeric rating scales.

Enrollment: 75 estimated patients

Sex: All

Ages: 20 to 85 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Age between 20 - 85 years.
• Characteristic symptoms of polyneuropathy for at least 6 months.
• Polyneuropathy diagnosis confirmed by typical clinical signs (distal sensory disturbance/lack of distal deep tendon reflexes) and/or electrophysiological tests and/or abnormal quantitative sensory tests.
• Total pain intensity rating of at least 4 on a 0-10 points numeric rating scale.
• Pain present at least 4 days a week.
• For diabetics: diabetes diagnosis for at least 6 months and stable metabolic control for at least 3 months.
• For other secondary polyneuropathies: stable for at least 6 months.
• For fertile females: adequate anticonceptive treatment.
• Written informed consent.

Exclusion criteria

• Other cause of pain.
• Contraindications against imipramine.
• Allergic reactions towards imipramine or pregabalin.
• Known adverse reactions during imipramine or pregabalin treatment.
• Pregnancy.
• Severe systemic disease.
• Ongoing treatment with antidepressants, antipsychotics, anticonvulsants, opioids, propranolol, kinidine, monoamine oxidase inhibitor.
• Inability to follow study protocol.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Quadruple Blind

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75 participants in 4 patient groups, including a placebo group

Imipramine

Active Comparator group

Description:

Imipramine tablets and placebo capsules to pregabalin

Treatment:

Drug: Imipramine

Pregabalin

Active Comparator group

Description:

Pregabalin capsules and placebo tablets to imipramine

Treatment:

Drug: Pregabalin

Imipramine plus pregabalin

Experimental group

Description:

Imipramine tablets and pregabalin capsules

Treatment:

Drug: Imipramine, pregabalin

Placebo

Placebo Comparator group

Description:

Placebo tablets to imipramine and placebo capsules to pregabalin

Treatment:

Drug: Placebo