Vitamin D and Cocaine Administration

Study Overview
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Brief Summary
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This study is designed to explore the effects of acute pre-treatment with 1,25-dihydroxyvitamin D3 (calcitriol), as compared to placebo on the behavioral (e.g., attempts to self-administer and ultimate number of infusions/boluses of cocaine self-administered), neurocognitive (e.g., performance on computerized tests of reward related learning such as the probabilistic selection task or PST and probabilistic reward task or PRT), and subjective effects (e.g, computerized visual analog scale [VAS] ratings of euphoria/, craving, etc.) of cocaine in experienced, non-treatment seeking users of the drug.

Official Title
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Testing Restoring Effects of Vitamin D on the Dopamine System: A Human Laboratory Study Among Cocaine Users.

Conditions
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Cocaine Use Disorder

Intervention / Treatment
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* Drug: Calcitriol
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 30-55 years Voluntary, written, informed consent Physically healthy by medical history, physical, neurological, ECG and laboratory examinations DSM-5 criteria for at least moderate Cocaine Use Disorder Recent street cocaine use in excess of quantities used in the current study Intravenous and/or smoked (crack/ freebase) use Positive urine toxicology screen for cocaine Laboratory evidence of vitamin D sufficiency (i.e., 25(OH)-vitamin D3 level ≥ 20/mg) For females, a negative serum pregnancy (HCG) test at screening and admission, and a negative urine pregnancy test (HCG) on cocaine administration days. Exclusion Criteria: A history of other substance dependence (except for nicotine). Positive urine toxicology for cannabis is accepted for the study unless there is evidence for dependence per Structured Clinical Interview for DSM-5 (SCID) interview. Positive urine toxicology for other drugs at screening will be repeated. If positive again and/or positive at admission, subjects will be excluded < 1 year of cocaine abuse/dependence A primary DSM-5 Axis I major psychiatric disorder (e.g., schizophrenia, bipolar disorder, major depression, etc.) unrelated to cocaine as determined by the SCID-5 Medical comorbidities including serum calcium ( > 10.5 mg/dl, serum phosphorus > 4.2 mg/dl), hyperparathyroidism, kidney disease (e.g., Serum creatinine > 1.3 mg/dl) A history of significant and uncontrolled medical (e.g., cardiovascular, diabetic/metabolic) or neurological (e.g., cerebrovascular, seizures, traumatic brain injury) illness A history of seizures Current use of psychotropic/potentially psychoactive medications or medications that can have drug drug interactions with calcitriol, including over the counter Vitamin D products, thiazide diuretics, and calcium supplements, etc, as referenced in the package insert for calcitriol Seeking treatment for drug abuse/dependence Hypersensitivity to calcitriol For females, physical or laboratory (HCG) evidence of pregnancy.

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Acute Pretreatment with Calcitriol<br>To explore the effects of acute pre-treatment with Calcitriol on attempts to self-administer and ultimate number of infusions/boluses of cocaine, in experienced, non treatment-seeking users of the drug | Drug: Calcitriol<br>* Subjects will receive an oral administration of calcitriol (1,25-dihydroxyvitamin D3) 1.5 μg (three capsules of 0.5 μg each) at 9 pm, night before each cocaine session, and at 8 am, morning of each cocaine session. This dose of calcitriol is lower than doses safely administered in other human studies and for a duration of time shorter than doses safely administered in other trials. In addition, this dose has been already tested by our group, subject of a different grant application, and should be effective at enhancing stimulant's induced dopamine release, in comparison to placebo.<br>* Other names: 1,25-dihydroxyvitamin D3;|
| Placebo Comparator: Acute Pretreatment with Placebo<br>To explore the effects of acute pre-treatment with placebo on attempts to self-administer and ultimate number of infusions/boluses of cocaine, in experienced, non treatment-seeking users of the drug | Other: Placebo<br>* Subjects will receive an oral administration of three capsules of placebo at 9 pm the night before each cocaine session, and at 8 am, morning of each cocaine session.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cocaine Self Administration Attempts | Number of attempts to self administer cocaine will be analyzed. | 90 minutes | 
| Cocaine Self Administration Infusions | Number of infusions of cocaine will be analyzed. | 90 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Probabilistic Selection Task (PST) | The Probabilistic Selection Task (PST) is a computerized task that assesses the tendency to learn from positive versus negative outcomes. PST will be analyzed using linear mixed models with treatment and time included as a within subjects variable. | 15 minutes | 
| Probabilistic Reward Task (PRT) | The Probabilistic Reward Task (PRT) is a computerized task that uses an asymmetric reinforcement schedule to produce a response bias towards the more frequently rewarded of two possible stimuli. PRT will be analyzed using linear mixed models with treatment and time included as a within subjects variable. | 15 minutes | 
| Subjective Effects of Cocaine / Visual Analog Scale (VAS) | During cocaine sessions, subjects will complete a series of self rated subjective effects measuring how they feel on cocaine, using a scale of 0 (not at all) to 10 (most ever). VAS ratings will focus on euphoria (high) as a primary outcome, however, other positive, negative, psychomotor, and drug-craving ratings (e.g. good, bad, stimulated, paranoid, hungry, etc.) will be collected as well. Ratings are implemented on a touch-screen laptop computer and presented every 5 minutes, throughout the session | 150 minutes |