Abnormal Ventilatory Response to Carbon Dioxide: a Potential Biomarker for Seizure Induced Respiratory Depression & Modification by SSRI
Study Details
Study Description
Brief Summary
Sudden unexpected death in epilepsy patients (SUDEP) is devastating outcome for some patients with epilepsy. It ranks second only to stroke among neurological diseases in years of potential life lost. Patho-mechanisms of SUDEP remain not well understood, however peri-ictal respiratory dysfunction likely plays an important role in many cases.
Literature supports a critical role for the serotonergic system in central control of ventilation. Serotonin neurons in the raphe nuclei of the brainstem sense rising carbon dioxide and low pH, thereby stimulating breathing and arousal. These responses may serve as mechanisms that protect against asphyxia, particularly during sleep or the post-ictal state. In mouse models of seizure-induced sudden death, pre-treatment with selective serotonin reuptake inhibitor (SSRI) agents prevents death following seizures. Hence, the investigators hypothesize that a subset of drug resistant epilepsy patients who have impaired central chemo-responsiveness have a greater degree of peri-ictal respiratory depression, therefore a higher risk of SUDEP. The investigators further hypothesize that fluoxetine will improve central chemo-responsiveness and therefore will reduce peri-ictal respiratory depression.
Condition or Disease | Intervention/Treatment | Phase |
---|---|---|
|
Phase 2 |
Detailed Description
Sudden unexpected death in epilepsy (SUDEP) refers to the sudden, unexpected, nontraumatic, non-drowning, witnessed or unwitnessed death of an individual with epilepsy. Postmortem examination in such cases fails to reveal an obvious medical or toxicologic cause for the death, and patients who die from SUDEP are typically healthy apart from their epilepsy. The incidence of SUDEP in epilepsy patients is estimated to be 0.1 in 1000 patient years, and this rate increases to >9.3 per 1000 for those with durg resistant epilepsy (DRE) who are candidates for epilepsy surgery. Although thought to be rare, SUDEP is estimated to be responsible for 17% of all deaths in patients with epilepsy, and approximately 50% of all deaths in patients with DRE. It is second only to stroke among neurological diseases in YPLL because many who die of SUDEP are relatively young and therefore it is a major public health concern. While there are some acknowledged risk factors for SUDEP, the actual cause, or causes, of SUDEP is not known. Seizure induced respiratory depression is likely to be a major contributor in SUDEP in many cases.
Preliminary results from the ventilatory response to CO2 or hypercapnic ventilatory response (HCVR) study of patient with epilepsy in epilepsy monitoring unit (EMU) suggests prolonged period of CO2 elevation after seizures correlating with low HCVR. These findings suggest a defect in CO2 responsiveness in this high-risk population that may predispose to SUDEP. Serotonin nerve cells in the brain stem are responsible for detecting increases in CO2, and in response stimulating breathing and arousal from sleep. Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) drug that increases availability of serotonin in the brain. As such, it may serve to stimulate breathing after seizures in patients with epilepsy who exhibit low CO2 sensitivity at baseline and this may alter SUDEP risk.
This study consists of a double blind randomized controlled clinical trial with a 6-week titration of an intervention. It is designed to evaluate primarily feasibility of a larger clinical trial testing efficacy of fluoxetine in modifying HCVR in patients with epilepsy while also collecting important secondary and exploratory outcomes that would be valuable for designing future larger studies.
We will evaluate challenges in screening, enrollment, randomization, and completion of study-related procedures by quantifying the numbers of subjects eligible for screening, the number of subjects enrolled in the study per month, the proportion of patients successfully completing the study, and the specific challenges at each step. We will also assess challenges in setting up and performing outpatient HCVR testing.
Study Design
Arms and Interventions
Arm | Intervention/Treatment |
---|---|
Active Comparator: Treatment Subjects randomized to treatment arm will receive fluoxetine with titration schedule consisting of 10 mg per day for 1 week, 20 mg per day for 1 week, 40 mg per day for 2 weeks, 20 mg per day for 1 week and 10 mg per day for 1 week. Then stop. |
Drug: Fluoxetine
Standard 6 weeks titration, starting 10 mg per day.
Other Names:
|
Placebo Comparator: Control Subjects randomized to control arm will receive placebo with titration schedule consisting of 10 mg per day for 1 week, 20 mg per day for 1 week, 40 mg per day for 2 weeks, 20 mg per day for 1 week and 10 mg per day for 1 week. Then stop. |
Drug: Placebo
Standard 6 weeks titration.
|
Outcome Measures
Primary Outcome Measures
- Study Recruitment Rate [From the date of enrollment every 3 months up to 2 years]
Number of participants enrolled every 3 months.
- Study Retention Rate [From date of enrollment until either completion of study or lost to follow up every 3 months up to 2 years and 3 months]
Number of participants completing the study every 3 months.
Secondary Outcome Measures
- Change in Minute Ventilation During Hypercapnic Ventilatory Response (HCVR) Testing [At the end of HCVR testing- at baseline and 4 weeks after receiving an intervention]
Minute ventilation was evaluated at baseline HCVR testing and HCVR testing at 4 weeks after receiving an intervention. Change from baseline was calculated.
- Change in PHQ-9 Score. [At baseline and 4 weeks after randomization to an intervention]
Patient Health Questionnaire (PHQ-9) was used to evaluate mood. Score on PHQ-9 scale ranges from 0-27. Scores corresponding to severity of depression: 0-4: minimal to none ; 5-9: mild; 10-14: moderate; 15-19 moderately severe; 20-27: severe. All subjects in the study were interviewed using standard questions per PHQ-09 questionnaire at baseline and 4 weeks after randomization to an intervention.
- Change in Slope of HCVR [At baseline and 4 weeks after receiving an intervention]
All the subjects undergo CO2 rebreathing (HCVR) testing at baseline and 4 weeks after receiving an intervention. During CO2 rebreathing (HCVR) testing, CO2 gradually rise in the body that stimulates breathing, which in turn increases minute ventilation (L/min). The rate of this increase in minute ventilation with each mm Hg rise in CO2 is the HCVR slope, which is calculated for baseline testing and 4 weeks after receiving an intervention. HCVR slope at 4 weeks after receiving an intervention compared to the baseline HCVR slope in each group.
Eligibility Criteria
Criteria
Inclusion Criteria:
-
Adult patients aged 18 or older
-
Patients with epilepsy
-
Native English speaker or adequate fluency in English to provide informed consent.
-
Female patients of child-bearing potential must be using an acceptable method of contraception, and willing to refrain from sexual intercourse during the study.
Exclusion Criteria:
-
Progressive neurological disease.
-
Clinical diagnosis of bipolar disease, panic disorder, psychosis or severe depression, or PHQ-9 score > 20
-
Patients with prior hospitalization related to depression or Electroconvulsive therapy.
-
History of suicidal ideation or intent in past or present
-
Clinical history or laboratory evidence of hepatic or renal insufficiency.
-
Pregnant or lactating women.
-
Current heavy alcohol use (>14 drinks per week for men or >7 drinks per week for women) or) known medical disorder related to alcohol use or current illicit drug use, other than marijuana and its derivatives.
-
Patients with recent use (<1 month) or already taking fluoxetine or other selective serotonin reuptake inhibitors (SSRIs).
-
Concurrent use of monoamine oxidase inhibitors, antipsychotic agents, antidepressant agents other than SSRIs or frequent use of triptan agents (>2/week).
-
History of a previous allergic reaction or adverse effects with fluoxetine, hypersensitive reaction-anaphylaxis; laryngeal edema; hives
-
History of serotonin syndrome.
-
History of uncontrolled pulmonary or cardiac illness.
-
Patients with hypercapnic ventilatory response (HCVR) slope of > 2.0
-
Patients with known prolong QT interval
-
Patients with family history of prolong QT interval
-
Patients with family history of sudden cardiac death under the age of 40 in a first degree relative.
Contacts and Locations
Locations
Site | City | State | Country | Postal Code | |
---|---|---|---|---|---|
1 | The Univeristy of Iowa Hospitals and Clinics | Iowa City | Iowa | United States | 52242 |
2 | Univeristy of Iowa Hospitals and Clinics | Iowa City | Iowa | United States | 52242 |
Sponsors and Collaborators
- Rup Kamal Sainju
Investigators
- Principal Investigator: Rup Sainju, University of Iowa
Study Documents (Full-Text)
More Information
Publications
None provided.- 201607761
Study Results
Participant Flow
Recruitment Details | A total of 30 subjects enrolled from February 2017 to February 2019. These 30 subjects underwent further screening before randomization to an intervention. Eight of the subjects failed to meet eligibility for randomization to an intervention, hence only 22 participants were randomized equally (1:1) to one of the treatment arms. |
---|---|
Pre-assignment Detail | A total of 6 subjects with HCVR slope of > 2.0 L/min/mm Hg were excluded.Two additional subjects did not meet other inclusion criteria for randomization. |
Arm/Group Title | Treatment | Control |
---|---|---|
Arm/Group Description | Subjects randomized to treatment arm will receive fluoxetine with titration schedule consisting of 10 mg per day for 1 week, 20 mg per day for 1 week, 40 mg per day for 2 weeks, 20 mg per day for 1 week and 10 mg per day for 1 week. Then stop. Fluoxetine: Standard 6 weeks titration, starting 10 mg per day. | Subjects randomized to control arm will receive placebo with titration schedule consisting of 10 mg per day for 1 week, 20 mg per day for 1 week, 40 mg per day for 2 weeks, 20 mg per day for 1 week and 10 mg per day for 1 week. Then stop. Placebo: Standard 6 weeks titration. |
Period Title: Overall Study | ||
STARTED | 11 | 11 |
COMPLETED | 11 | 11 |
NOT COMPLETED | 0 | 0 |
Baseline Characteristics
Arm/Group Title | Treatment | Control | Total |
---|---|---|---|
Arm/Group Description | Subjects randomized to treatment arm will receive fluoxetine with titration schedule consisting of 10 mg per day for 1 week, 20 mg per day for 1 week, 40 mg per day for 2 weeks, 20 mg per day for 1 week and 10 mg per day for 1 week. Then stop. Fluoxetine: Standard 6 weeks titration, starting 10 mg per day. | Subjects randomized to control arm will receive placebo with titration schedule consisting of 10 mg per day for 1 week, 20 mg per day for 1 week, 40 mg per day for 2 weeks, 20 mg per day for 1 week and 10 mg per day for 1 week. Then stop. Placebo: Standard 6 weeks titration. | Total of all reporting groups |
Overall Participants | 11 | 11 | 22 |
Age (Count of Participants) | |||
<=18 years |
0
0%
|
0
0%
|
0
0%
|
Between 18 and 65 years |
11
100%
|
11
100%
|
22
100%
|
>=65 years |
0
0%
|
0
0%
|
0
0%
|
Sex: Female, Male (Count of Participants) | |||
Female |
1
9.1%
|
4
36.4%
|
5
22.7%
|
Male |
10
90.9%
|
7
63.6%
|
17
77.3%
|
Race (NIH/OMB) (Count of Participants) | |||
American Indian or Alaska Native |
0
0%
|
0
0%
|
0
0%
|
Asian |
0
0%
|
0
0%
|
0
0%
|
Native Hawaiian or Other Pacific Islander |
0
0%
|
0
0%
|
0
0%
|
Black or African American |
0
0%
|
0
0%
|
0
0%
|
White |
11
100%
|
11
100%
|
22
100%
|
More than one race |
0
0%
|
0
0%
|
0
0%
|
Unknown or Not Reported |
0
0%
|
0
0%
|
0
0%
|
Region of Enrollment (participants) [Number] | |||
United States |
11
100%
|
11
100%
|
22
100%
|
Outcome Measures
Title | Study Recruitment Rate |
---|---|
Description | Number of participants enrolled every 3 months. |
Time Frame | From the date of enrollment every 3 months up to 2 years |
Outcome Measure Data
Analysis Population Description |
---|
Due to being a feasibility study, recruitment is reported for the whole population (drug + placebo). |
Arm/Group Title | Recruitment |
---|---|
Arm/Group Description | Number of subjects (both fluoxetine and placebo arms) enrolled in the study. |
Measure Participants | 30 |
Mean (Full Range) [participants/3 months] |
3.8
34.5%
|
Title | Study Retention Rate |
---|---|
Description | Number of participants completing the study every 3 months. |
Time Frame | From date of enrollment until either completion of study or lost to follow up every 3 months up to 2 years and 3 months |
Outcome Measure Data
Analysis Population Description |
---|
[Not Specified] |
Arm/Group Title | Fluoxetine | Placebo |
---|---|---|
Arm/Group Description | Subjects randomized to receive fluoxetine. | Subjects randomized to receive placebo. |
Measure Participants | 11 | 11 |
Mean (Full Range) [participants/3 months] |
1.2
10.9%
|
1.1
10%
|
Title | Change in Minute Ventilation During Hypercapnic Ventilatory Response (HCVR) Testing |
---|---|
Description | Minute ventilation was evaluated at baseline HCVR testing and HCVR testing at 4 weeks after receiving an intervention. Change from baseline was calculated. |
Time Frame | At the end of HCVR testing- at baseline and 4 weeks after receiving an intervention |
Outcome Measure Data
Analysis Population Description |
---|
Minute ventilation at the end of HCVR- 4 weeks after receiving an intervention was compared to minute ventilation during baseline HCVR testing in each group. |
Arm/Group Title | Fluoxetine | Placebo |
---|---|---|
Arm/Group Description | Subjects randomized to receive fluoxetine. | Subjects randomized to receive placebo. |
Measure Participants | 11 | 11 |
Mean (95% Confidence Interval) [Liters/minute (L/min)] |
1.739
|
2.758
|
Title | Change in PHQ-9 Score. |
---|---|
Description | Patient Health Questionnaire (PHQ-9) was used to evaluate mood. Score on PHQ-9 scale ranges from 0-27. Scores corresponding to severity of depression: 0-4: minimal to none ; 5-9: mild; 10-14: moderate; 15-19 moderately severe; 20-27: severe. All subjects in the study were interviewed using standard questions per PHQ-09 questionnaire at baseline and 4 weeks after randomization to an intervention. |
Time Frame | At baseline and 4 weeks after randomization to an intervention |
Outcome Measure Data
Analysis Population Description |
---|
PHQ-9 scores 4 weeks of receiving an intervention is compared to the baseline scores in each group. |
Arm/Group Title | Fluoxetine | Placebo |
---|---|---|
Arm/Group Description | Subjects randomized to receive fluoxetine. | Subjects randomized to receive placebo. |
Measure Participants | 11 | 11 |
Mean (95% Confidence Interval) [score on a scale] |
0.455
|
-1.000
|
Title | Change in Slope of HCVR |
---|---|
Description | All the subjects undergo CO2 rebreathing (HCVR) testing at baseline and 4 weeks after receiving an intervention. During CO2 rebreathing (HCVR) testing, CO2 gradually rise in the body that stimulates breathing, which in turn increases minute ventilation (L/min). The rate of this increase in minute ventilation with each mm Hg rise in CO2 is the HCVR slope, which is calculated for baseline testing and 4 weeks after receiving an intervention. HCVR slope at 4 weeks after receiving an intervention compared to the baseline HCVR slope in each group. |
Time Frame | At baseline and 4 weeks after receiving an intervention |
Outcome Measure Data
Analysis Population Description |
---|
During CO2 rebreathing (HCVR) testing, CO2 gradually rise in the body that stimulates breathing, which in turn increases minute ventilation (L/min). The rate of this increase in minute ventilation with each mm Hg rise in CO2 is the HCVR slope, hence expressed as L/min/mm Hg unit. |
Arm/Group Title | Fluoxetine | Placebo |
---|---|---|
Arm/Group Description | Subjects randomized to fluoxetine. | Subjects randomized to receive placebo. |
Measure Participants | 11 | 11 |
Mean (95% Confidence Interval) [Liters/minute/mm Hg (L/min/mm Hg)] |
-0.049
|
0.072
|
Adverse Events
Time Frame | Adverse events were monitored and collected after randomization up to 7 weeks from study drug initiation or study dropout which ever was closer. | |||
---|---|---|---|---|
Adverse Event Reporting Description | We used definition of adverse events similar to clinicaltrials.gov. | |||
Arm/Group Title | Fluoxetine | Placebo | ||
Arm/Group Description | Subjects randomized to treatment arm will receive fluoxetine with titration schedule consisting of 10 mg per day for 1 week, 20 mg per day for 1 week, 40 mg per day for 2 weeks, 20 mg per day for 1 week and 10 mg per day for 1 week. Then stop. Fluoxetine: Standard 6 weeks titration, starting 10 mg per day. | Subjects randomized to control arm will receive placebo with titration schedule consisting of 10 mg per day for 1 week, 20 mg per day for 1 week, 40 mg per day for 2 weeks, 20 mg per day for 1 week and 10 mg per day for 1 week. Then stop. Placebo: Standard 6 weeks titration. | ||
All Cause Mortality |
||||
Fluoxetine | Placebo | |||
Affected / at Risk (%) | # Events | Affected / at Risk (%) | # Events | |
Total | 0/11 (0%) | 0/11 (0%) | ||
Serious Adverse Events |
||||
Fluoxetine | Placebo | |||
Affected / at Risk (%) | # Events | Affected / at Risk (%) | # Events | |
Total | 0/11 (0%) | 0/11 (0%) | ||
Other (Not Including Serious) Adverse Events |
||||
Fluoxetine | Placebo | |||
Affected / at Risk (%) | # Events | Affected / at Risk (%) | # Events | |
Total | 1/11 (9.1%) | 0/11 (0%) | ||
Nervous system disorders | ||||
Moderate, probably related | 1/11 (9.1%) | 1 | 0/11 (0%) | 0 |
Limitations/Caveats
More Information
Certain Agreements
Principal Investigators are NOT employed by the organization sponsoring the study.
There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.
Results Point of Contact
Name/Title | Dr. Rup Sainju |
---|---|
Organization | University of Iowa |
Phone | 319-356-4337 |
rup-sainju@uiowa.edu |
- 201607761