Summary
Halazepam is a trifluoromethyl derivative of nordazepam (desmethyldiazepam) with anxiolytic, anticonvulsant, sedative, and muscle relaxant properties. It is metabolized into pharmacologically active desmethyldiazepam with a half-life of 30-100 hours, contributing to prolonged effects and accumulation with repeated use. Halazepam was marketed as having lower toxicity and less tendency to cause paradoxical hostility than diazepam, though it was withdrawn from the US market in 2009 due to poor sales. Like all benzodiazepines, it carries significant risks of dependence, cognitive impairment, and dangerous interactions with other depressants. Abrupt discontinuation after prolonged use can cause life-threatening withdrawal seizures.
Dose Information
| ROA | Light | Common | Strong | Heavy |
|---|---|---|---|---|
| Oral | 10-20mg | 20-40mg | 40-80mg | 80mg+ |
Light
Common
Strong
Heavy
Onset, Duration & After-effects
| ROA | Onset | Comeup | Peak | Offset | After Effects | Total |
|---|---|---|---|---|---|---|
| Oral | 30-60 min | 1-2 hrs | 1-3 hrs | 6-12 hrs | 24-48 hrs | 480-0 min |
Tolerance
Build-up
develops over 1–4 weeks of daily use; hypnotic tolerance faster than anxiolytic tolerance
Reset
weeks to months depending on half-life and duration of use; taper recommended
Effects
Positive
- Muscle relaxation
- Physical euphoria
- Anxiolytic
- Muscle Relaxant
Negative
- Respiratory depression
- Motor impairment
- Sedation
- Sedative
- Dystaxia
- Hypnotic
Positive
- Anxiety suppression
- Cognitive euphoria
Negative
- Motor control loss
- Thought deceleration
- Emotion suppression
- Memory suppression
- Amnesia
- Dizziness
- Compulsive redosing
- Delusions of sobriety
Positive
- Increased libido
- Appetite enhancement
Negative
- Disinhibition
- Acuity suppression
- Visual acuity suppression
- Decreased Libido
- Acuity Suppression
- Double vision
- Dulled perception
- Perception of bodily heaviness