Summary
Fosazepam is a water-soluble phosphate ester derivative of diazepam with approximately 10-fold lower potency (100 mg fosazepam equals 10 mg diazepam). It is a prodrug that is metabolized to desmethyldiazepam (nordiazepam), which has a very long elimination half-life of approximately 72 hours. This long-acting metabolite can cause extended sedation and accumulation with repeated dosing. Clinical trials showed it suppresses deep sleep stages while increasing light sleep duration. Not recommended for use as a hypnotic due to residual morning sedation.
Dose Information
| ROA | Light | Common | Strong | Heavy |
|---|---|---|---|---|
| Oral | 30-50mg | - | - | - |
Light
Common
Strong
Heavy
Onset, Duration & After-effects
| ROA | Onset | Comeup | Peak | Offset | After Effects |
|---|---|---|---|---|---|
| Oral | 30-90 min | 1-2 hrs | 2-4 hrs | 4-8 hrs | 12-72 hrs |
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
- Stimulation
- Physical Euphoria
Negative
- Motor impairment
- Nausea
- Increased heart rate
- Increased blood pressure
- Increased perspiration
- Vasoconstriction
- Sedation
Positive
- Anxiety suppression
- Wakefulness
- Cognitive Euphoria
Negative
- Amnesia
- Drowsiness
- Motor control loss
- Thought deceleration
- Emotion suppression
- Anxiety
- Time Distortion
Positive
- Increased libido
- Tactile Enhancement
- Increased Music Appreciation
- Pattern Recognition Enhancement
Negative
- Disinhibition
- Appetite suppression
- Light sensitivity
- Dulled perception
- Auditory hallucination
- Auditory distortion