Conditions: Erythromelalgia
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 2
Healthy volunteers: no

Brief summary:
This research study is designed to investigate brain response using fMRI scan, and behavioral responses, to treatment with the drug carbamazepine (CBZ) in patients with the painful sodium channelopathy inherited Erythromelalgia (IEM). This study is designed to identify the central nervous system (CNS) regions that are activated during ongoing or evoked pain attacks, and the altered CNS response to CBZ treatment. This will advance our understanding of how IEM affects the brain. We also hope to validate a pharmacogenic approach to the study of IEM by use of an FDA approved drug. We hope, but cannot be sure, that subjects will directly benefit from this study.

Detailed description:

Arms:
arm 1: Administered in gradual doses from 200 mg twice a day increasing to no more than 800 mg twice a day if symptoms do not reduce. After 2 weeks of steady dose drug will be tapered down every 3 days. arm 2: Administered in gradual doses from 200 mg twice a day increasing to no more than 800 mg twice a day if symptoms do not reduce to match dosing with carbamazepine. After 2 weeks of steady dose drug will be tapered down every 3 days.

Interventions: intervention 1: Carbamazepine intervention 2: Placebo
Intervention descriptions: intervention 1: Day 1: Take 200 mg twice a day. Day 2: Take 200 mg twice a day. Day 3: Take 200 mg twice a day. Day 4: Take 200 mg twice a day. Day 5: Take 400 mg twice a day. Day 6: Take 400 mg twice a day. Day 7: Take 400 mg twice a day. Day 8: Take 400 mg twice a day. Day 9: Take 600 mg twice a day. Day 10: Take 600 mg twice a day. Day 11: Take 600 mg twice a day. Day 12: Take 600 mg twice a day. Day 13: Take 800 mg capsules twice a day. Day 14: Take 800 mg twice a day. Day 15: 800 mg twice a day. Day 16: Take 800 mg twice a day.

Taper Down (After Visit 4 and 7) If maximal dose of 800 mg/day has been achieved, tapering down will take 9 days Taper down for 600 mg/day will take 6 days, and for 400 mg/day will take 3 days. intervention 2: None

Protocol document: