no Condition, Basic ScienceNCT03416569
Effects of Prazosin on the Attention-Enhancing Effects of Nicotine
A study testing Nicotine, Prazosin and Nicotine + Prazosin in people with no Condition, Basic Science, run by University of Maryland, Baltimore.
Trial summary
To test whether specific aspects of the attention-enhancing effects of nicotine may be mediated by down-stream activation of alpha1 adrenoceptors, the interaction of nicotine and the alpha1 adrenergic antagonist prazosin on cognitive task performance will be tested in human non-smokers. Read more about this study
- Who is it for?
- Ages 21 to 55 yearsHealthy volunteers can take part
- Conditions the study is for
- no Condition, Basic Science
- What is being tested?
- Nicotine, Prazosin and Nicotine + Prazosin
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 0 participants
- Where
- No sites listed yet
- Study dates
- Mar 2018to Jan 2019
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 to 55 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Aged 21 to 55 years.
- Smoked no more that 40 cigarettes, cigars or cigarillos in lifetime.
- Smoked no cigarettes, cigars or cigarillos in the last year.
- No exposure to any nicotine-containing product in the last month.
- Normal or corrected to normal vision (at least 20/80).
Who cannot join
- Pregnant or breast-feeding.
- Drug or alcohol abuse or dependence currently or in the last 2 years.
- DSM Axis I mood, anxiety or psychotic disorder.
- Cardiovascular or cerebrovascular disease.
- Hypertension (resting systolic BP above 150 or diastolic above 95 mm Hg).
- Hypotension (resting systolic BP below 90 or diastolic below 60).
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- Bradycardia (heart rate <60 bpm).
- Impaired liver or kidney function.
- Severe asthma.
- Obstructive pulmonary disease.
- Type I diabetes.
- Use of any centrally active medications.
- Use of any cardiovascular drugs, including blood pressure medications and antiarrhythmics.
- Use of diuretic medication.
- History of or current neurological illnesses, such as stroke, seizure disorders, neurodegenerative diseases, or organic brain syndrome.
- Learning disability, mental retardation, or any other condition that impedes cognition.
- Planned eye surgery.
- Inability to perform the Rapid Visual Information Processing Task.
- Known hypersensitivity to prazosin, any quinazolines, or nicotine.
- Narcolepsy.
About this study
Official title: The Effects of Prazosin on the Attention-Enhancing Effects of Nicotine in Healthy Non-Smokers
To test whether specific aspects of the attention-enhancing effects of nicotine may be mediated by down-stream activation of alpha1 adrenoceptors, the interaction of nicotine and the alpha1 adrenergic antagonist prazosin on cognitive task performance will be tested in human non-smokers. The effects of a low-dose nicotine patch vs. a placebo patch will be tested in the presence and absence of prazosin over 4 test sessions.
Read the detailed description
Drugs that activate nicotinic acetylcholine receptors (nAChRs), such as nicotine, have cognitive enhancing, and in particular attention-enhancing effects that may be of clinical benefit to individuals with cognitive deficits, such as those diagnosed with Alzheimer's disease, schizophrenia, or ADHD. nAChR agonists can increase the release of other neurotransmitters in the brain, including dopamine, noradrenaline, serotonin, glutamate and GABA. To date, it is unknown which of these actions is central to mediating the attention-enhancing effects of nAChR agonists. Such knowledge would channel drug development efforts onto subtypes of the nAChR expressed on and activating the target system, but not systems such as the subcortical dopamine system involved in unwanted effects of nAChR agonists (e.g., dependence).
Preclinical studies have suggested that the noradrenergic system is critical to the attention-enhancing effects of the prototypical nAChR agonist nicotine. Activation of alpha1-adrenergic receptors appears to be involved in broadening the attentional window, an effect shared with nicotine. The aim of the present study is to test whether the effects of nicotine on broad monitoring may be mediated by alpha1 adrenoceptors by testing the interaction of nicotine and the predominantly alpha1 adrenergic antagonist prazosin in healthy human non-smokers. The effects of a low-dose nicotine patch vs. a placebo patch will be tested in the presence and absence of prazosin in a 2 x 2 within-subject design, over 4 repeated test sessions, in healthy never-smokers. Each participant is asked to complete for test session, on separate days. In each session, a skin patch will be applied and a capsule given by mouth. In one session, both are a placebo. In another session, the patch contains nicotine (7 mg/24 hrs) and the capsule is a placebo. In another session, the patch is a placebo and the capsule contains 1 mg of prazosin. In another session, the patch contains nicotine and the capsule contains prazosin. The sequence of these testing conditions is counterbalanced and double-blind.
- Conditions
- no Condition, Basic Science
- Being tested
- Placebo, Nicotine, Prazosin, Nicotine + Prazosin
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PlaceboDrug
placebo skin patch + placebo capsule
NicotineDrug
nicotine patch (7 mg/24 hrs) + placebo capsule
PrazosinDrug
placebo patch (7 mg/24 hrs) + prazosin capsule (1 mg)
Nicotine + PrazosinDrug
nicotine patch (7 mg/24 hrs) + prazosin capsule (1 mg)
| Study group | Role | What they receive |
|---|---|---|
| Nicotine-Prazosin Interaction Study | Experimental | Over four test days, each participant will be tested with placebo, nicotine alone, prazosin alone, and nicotine + prazosin, in a double-blind sequence. Receives: Drug: Placebo; Drug: Nicotine; Drug: Prazosin; Drug: Nicotine + Prazosin |
What is being measured
The primary outcome is the main question the study is designed to answer.
Spatial Attentional Resource Allocation Task reaction time
average reaction time of trials with a signal detection response
Measured: 5 hrs after patch application (=2.5 hr after ingestion of capsule)
Spatial Attentional Resource Allocation Task omission errors
percentage of trials on which no response was registered
Measured: 5 hrs after patch application (=2.5 hr after ingestion of capsule)
Rapid Visual Information Processing Task hit rate
percentage of targets detected
Measured: 5 hrs after patch application (=2.5 hr after ingestion of capsule)
Rapid Visual Information Processing Task reaction time
average reaction time on trials with a correct response
Measured: 5 hrs after patch application (=2.5 hr after ingestion of capsule)
Change Detection Task accuracy
percentage of correct responses
Measured: 5 hrs after patch application (=2.5 hr after ingestion of capsule)
Change Detection reaction time
average reaction time across trials
Measured: 5 hrs after patch application (=2.5 hr after ingestion of capsule)
Secondary outcomes (2)
Blood pressure
mmHg
Measured: hourly for 8 hours on each test day
Vital signs: heart rate
beats per minute
Measured: hourly for 8 hours on each test day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Jan 2018
- Study startMar 2018 (estimated)
- Primary completionJan 2019 (estimated)
- Study completionJan 2019 (estimated)
Why it stopped: Unanticipated staff changes are preventing completion within funding period.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for no Condition, Basic ScienceStudies of the same condition, open and under way.
- More trials run by University of Maryland, BaltimoreThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Each participant is tested with each of four test conditions, in counterbalanced sequence.
- Masking
- None (open label)
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Maryland, Baltimore
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Britta Hahn, University of Maryland, Baltimore
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03416569
- Sponsor's protocol ID
- HP-00078832
- Status last verified
- Aug 2019
- First submitted
- 24 Jan 2018
- Last updated
- 19 Aug 2019
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 19 Aug 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effects of Prazosin on the Attention-Enhancing Effects of Nicotine in Healthy Non-Smokers
- ClinicalTrials.gov ID
- NCT03416569
- Acronym / sponsor ID
- HP-00078832
- Conditions
- no Condition, Basic Science
- Study type
- Interventional
- Recruitment status
- WithdrawnReason stopped: Unanticipated staff changes are preventing completion within funding period.
- Enrolment
- 0 participants (actual)
- Lead sponsor
- University of Maryland, BaltimoreUniversity, hospital or other
- Study start
- Mar 2018 (estimated)
- Primary completion
- Jan 2019 (estimated)
- Study completion
- Jan 2019 (estimated)
- First posted
- 31 Jan 2018 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
To test whether specific aspects of the attention-enhancing effects of nicotine may be mediated by down-stream activation of alpha1 adrenoceptors, the interaction of nicotine and the alpha1 adrenergic antagonist prazosin on cognitive task performance will be tested in human non-smokers. The effects of a low-dose nicotine patch vs. a placebo patch will be tested in the presence and absence of prazosin over 4 test sessions.
Detailed description
Drugs that activate nicotinic acetylcholine receptors (nAChRs), such as nicotine, have cognitive enhancing, and in particular attention-enhancing effects that may be of clinical benefit to individuals with cognitive deficits, such as those diagnosed with Alzheimer's disease, schizophrenia, or ADHD. nAChR agonists can increase the release of other neurotransmitters in the brain, including dopamine, noradrenaline, serotonin, glutamate and GABA. To date, it is unknown which of these actions is central to mediating the attention-enhancing effects of nAChR agonists. Such knowledge would channel drug development efforts onto subtypes of the nAChR expressed on and activating the target system, but not systems such as the subcortical dopamine system involved in unwanted effects of nAChR agonists (e.g., dependence).
Preclinical studies have suggested that the noradrenergic system is critical to the attention-enhancing effects of the prototypical nAChR agonist nicotine. Activation of alpha1-adrenergic receptors appears to be involved in broadening the attentional window, an effect shared with nicotine. The aim of the present study is to test whether the effects of nicotine on broad monitoring may be mediated by alpha1 adrenoceptors by testing the interaction of nicotine and the predominantly alpha1 adrenergic antagonist prazosin in healthy human non-smokers. The effects of a low-dose nicotine patch vs. a placebo patch will be tested in the presence and absence of prazosin in a 2 x 2 within-subject design, over 4 repeated test sessions, in healthy never-smokers. Each participant is asked to complete for test session, on separate days. In each session, a skin patch will be applied and a capsule given by mouth. In one session, both are a placebo. In another session, the patch contains nicotine (7 mg/24 hrs) and the capsule is a placebo. In another session, the patch is a placebo and the capsule contains 1 mg of prazosin. In another session, the patch contains nicotine and the capsule contains prazosin. The sequence of these testing conditions is counterbalanced and double-blind.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Each participant is tested with each of four test conditions, in counterbalanced sequence.
| Arm | Type | Receives |
|---|---|---|
| Nicotine-Prazosin Interaction Study | Experimental | Drug: Placebo, Drug: Nicotine, Drug: Prazosin, Drug: Nicotine + PrazosinOver four test days, each participant will be tested with placebo, nicotine alone, prazosin alone, and nicotine + prazosin, in a double-blind sequence. |
Who may qualify
- Ages
- 21 to 55 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Aged 21 to 55 years.
- Smoked no more that 40 cigarettes, cigars or cigarillos in lifetime.
- Smoked no cigarettes, cigars or cigarillos in the last year.
- No exposure to any nicotine-containing product in the last month.
- Normal or corrected to normal vision (at least 20/80).
Key exclusion criteria (20 listed)
- Pregnant or breast-feeding.
- Drug or alcohol abuse or dependence currently or in the last 2 years.
- DSM Axis I mood, anxiety or psychotic disorder.
- Cardiovascular or cerebrovascular disease.
- Hypertension (resting systolic BP above 150 or diastolic above 95 mm Hg).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Placeboplacebo skin patch + placebo capsule | Drug | Nicotine-Prazosin Interaction Study |
| Nicotinenicotine patch (7 mg/24 hrs) + placebo capsule | Drug | Nicotine-Prazosin Interaction Study |
| Prazosinplacebo patch (7 mg/24 hrs) + prazosin capsule (1 mg) | Drug | Nicotine-Prazosin Interaction Study |
| Nicotine + Prazosinnicotine patch (7 mg/24 hrs) + prazosin capsule (1 mg) | Drug | Nicotine-Prazosin Interaction Study |
Primary outcome
Spatial Attentional Resource Allocation Task reaction time
Time frame: 5 hrs after patch application (=2.5 hr after ingestion of capsule)
average reaction time of trials with a signal detection response
Spatial Attentional Resource Allocation Task omission errors
Time frame: 5 hrs after patch application (=2.5 hr after ingestion of capsule)
percentage of trials on which no response was registered
Rapid Visual Information Processing Task hit rate
Time frame: 5 hrs after patch application (=2.5 hr after ingestion of capsule)
percentage of targets detected
Rapid Visual Information Processing Task reaction time
Time frame: 5 hrs after patch application (=2.5 hr after ingestion of capsule)
average reaction time on trials with a correct response
Change Detection Task accuracy
Time frame: 5 hrs after patch application (=2.5 hr after ingestion of capsule)
percentage of correct responses
Change Detection reaction time
Time frame: 5 hrs after patch application (=2.5 hr after ingestion of capsule)
average reaction time across trials
2 secondary outcomes
Blood pressure
Time frame: hourly for 8 hours on each test day
Vital signs: heart rate
Time frame: hourly for 8 hours on each test day
Results and safety
The study was withdrawn before enrolling participants, so there are no results.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Aug 2019.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
Questions about this trial
What is this clinical trial studying?
A study testing Nicotine, Prazosin and Nicotine + Prazosin in people with no Condition, Basic Science, run by University of Maryland, Baltimore.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 20 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: withdrawn, as of the sponsor's last update on 19 Aug 2019. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was withdrawn before enrolling participants, so there are no results.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Spatial Attentional Resource Allocation Task reaction time (time frame: 5 hrs after patch application (=2.5 hr after ingestion of capsule)). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Aug 2019.