Pilot Study of Lofexidine and Methadone Pharmacodynamic Interaction in Methadone Maintained Patients

Inclusion Criteria:

1. Adult male and/or female, 18 to 60 years of age (inclusive)
2. Receiving methadone maintenance treatment for opioid dependence at a stable once-daily dose of 80-120 mg for at least 4 weeks prior to check-in for the Inpatient Treatment Visit.
3. Body mass index ≥ 18 and ≤ 35 (kg/m2).
4. Normal screening results or abnormal results that have been deemed by the Investigator as clinically insignificant.
5. Able to understand and willing to sign an informed consent form (ICF).
6. Females practicing adequate birth control or non-childbearing potential. Medically acceptable birth control methods for this study include intrauterine device (IUD); vasectomized partner (minimum of 6 months); post-menopausal (at least 2 years); surgically sterile (at least 6 months); double barrier (diaphragm with spermicide, condoms with vaginal spermicide); abstinence; implanted or intrauterine hormonal contraceptives in use for at least 6 consecutive months prior to study dosing and throughout the study duration; and oral, patch and injected hormonal contraceptives or vaginal hormonal device (ie, NuvaRing®) in use for at least 3 consecutive months prior to study dosing and throughout the study duration.

Exclusion Criteria:

1. Abnormal cardiovascular exam at screening and before randomization, including any of the following:

   • clinically significant abnormal electrocardiogram (ECG) (eg, significant first degree atrioventricular block, second or third degree heart block, clinically significant arrhythmia, or QTc interval (machine read) greater than 450 msec for males and greater than 470 msec for females)* heart rate < 55 bpm or symptomatic bradycardia*
   • systolic blood pressure (SBP) < 95 mmHg or symptomatic hypotension*
   • diastolic blood pressure (DBP) < 65 mmHg*
   • blood pressure (BP) > 155/95 mmHg*
   • change in orthostatic SBP, DBP, or heart rate >25% below recumbent values
   • prior history of myocardial infarction (MI) or evidence of prior MI on ECG* *ECGs and vitals may be repeated as appropriate in order to confirm values and rule out extraneous results.
2. History or presence of significant cardiovascular, hepatic, renal, hematological, gastrointestinal, endocrine, immunologic, psychiatric, neurologic, or dermatologic disease.
3. History or presence of any degree of chronic obstructive pulmonary disease.
4. History of suicidal ideations or depression requiring professional intervention including counseling or antidepressant medication.
5. Positive drug (urine)/alcohol (breath) test at Screening Visit or check-in to the Inpatient Clinic Visit excluding methadone. Subjects who have a positive test for heroin and benzodiazepines at the Screening Visit may be enrolled if the test is negative at check-in to the Inpatient Treatment Visit. Subjects who have a positive test for heroin or benzodiazepines at the Screening Visit must sign an ICF at check-in to the Inpatient Clinic Visit.
6. Receiving methadone for pain management.
7. Positive test for human immunodeficiency virus (HIV) or hepatitis B surface antigen (HBsAg). Subjects with a positive test for hepatitis C antibodies (HCV) may be enrolled if subject is asymptomatic.
8. Estimated creatinine clearance < 80 mL/minute at screening (Cockroft-Gault formula).
9. AST, ALT, or alkaline phosphatase > 3.0 x upper limit of normal at screening or check-in.
10. Amylase or lipase > 1.5 x upper limit normal at screening or check-in.
11. History of hypotension.
12. History of hypersensitivity or allergy to clonidine or any clonidine analogue.
13. Use of any new prescription medication within 12 days prior to check-in.
14. Use of any over-the-counter medication, including herbal products, within the 5 days prior to check-in. Up to 2 grams per day of acetaminophen is allowed at the discretion of the PI/PI‟s designee.
15. Use of any drug known to affect QTc within 30 days prior to check-in (tobacco excluded).
16. Blood donation or significant blood loss within 30 days prior to check-in.
17. Plasma donation within 7 days prior to check-in.
18. Participation in another clinical trial within 30 days prior to check-in.
19. Females who are pregnant or lactating.
20. Any other condition or prior therapy, which, in the opinion of the Investigator, would make the subject unsuitable for this study.