Nitrazepam

7-nitro-5-phenyl-1,3-dihydro-1,4-benzodiazepin-2-one

Overview

Nitrazepam belongs to Depressants / Benzodiazepines.

Key safety note: Nitrazepam is a strong, long-acting hypnotic, and its long half-life is the main practical hazard: sedation, impaired coordination, memory and reaction time carry over into the next day and accumulate with nightly use, raising the risk of falls and hip fractures (especially in the elderly) and of impaired driving.[2]
Effects
Subjective effects vary. What a substance feels like depends on dose, individual physiology, mindset, and setting. The points below describe commonly reported effects, not guaranteed, uniform, or desirable outcomes.
  • Drowsiness and sleep, muscle relaxation, calm and reduced anxiety.
  • Impaired coordination, memory and concentration, and, because of the long half-life, grogginess, unsteadiness and slowed reactions the next day.
  • With regular use: tolerance to the hypnotic effect, dependence, and rebound insomnia/anxiety and other withdrawal symptoms on stopping.
Dosing & duration
Harm-reduction note: These are commonly cited reference ranges, not a recommendation or a “safe” dose. Potency, purity, body chemistry, tolerance, and drug combinations vary widely. Start low, go slow, wait for full effects before redosing, and never assume an unknown product matches these figures. Missing data is not evidence of safety.

Oral (tablets), taken at night: prescribed and dose-adjusted by a clinician. Figures are therapeutic (prescribing) context, not a recreational guide.. Nitrazepam is a prescription hypnotic for short-term use. The long half-life means it accumulates and impairs the following day, so the lowest effective dose and the shortest course are used, with lower doses in the elderly. It should not be combined with alcohol, opioids or other sedatives, and users should not drive while affected (including the morning after).

Dose ranges

Adult (insomnia, at night)

5–10 mg

Elderly / debilitated

2.5–5 mg

Duration

onset

≈30–60 min (peak ~2 h)

total

Hypnotic effect overnight, sedation can persist into the next day

after effects

Next-day drowsiness/'hangover'. Rebound insomnia on stopping

Chemical & Physical Properties
FormulaC15H11N3O3
Molar mass281.27 g/mol
StateSolid
Melting point225 °C
Boiling pointNot reported
DensityNot reported
Vapor pressureNot reported
pKaNot reported
LogP2.25
Solubility2.99×10⁻² g/L, >42.2 [µg/mL] (The mean of the results at pH 7.4)
Refractive indexNot reported
Identifiers & Synonyms
CAS146-22-5
CAS (enantiomer)
PubChem CID4506
InChIKeyKJONHKAYOJNZEC-UHFFFAOYSA-N
InChIInChI=1S/C15H11N3O3/c19-14-9-16-15(10-4-2-1-3-5-10)12-8-11(18(20)21)6-7-13(12)17-14/h1-8H,9H2,(H,17,19)
SMILESC1C(=O)NC2=C(C=C(C=C2)[N+](=O)[O-])C(=N1)C3=CC=CC=C3

Synonyms

  • Mogadon
Pharmacodynamics & Biochemistry

Nitrazepam (Mogadon) is a long-acting nitro-benzodiazepine hypnotic. Like other benzodiazepines it is a positive allosteric modulator at the benzodiazepine site of the GABA-A receptor (the α/γ2 subunit interface). It does not open the channel itself but, in the presence of GABA, increases the frequency of chloride-channel opening, enhancing inhibitory neurotransmission to produce sedation, hypnosis, anxiolysis, muscle relaxation and anticonvulsant effects. It binds that site with high (nanomolar) affinity and behaves as a full agonist there. It is well absorbed orally (peak ~2 h) and metabolised in the liver without clinically significant active metabolites, but it is eliminated slowly: half-life roughly 16–38 hours (mean ~26 h, longer in the elderly). This long half-life means the drug and its sedation carry over into the next day ('hangover' effect) and accumulate with nightly use, which is why it is now generally reserved for short-term use and used cautiously in older people.

Biological targets

  • GABA-A

Binding & functional measurements

TargetMeasurementSpecies
GABA-A α1β2γ2 receptorEC50 52 nMHuman
Pharmacokinetics
BioavailabilityNot reported
Tmax≈2 h (range 0.5–5 h)
Half-life≈16–38 h (mean ≈26 h, longer in the elderly)
VdNot reported
Protein bindingNot reported
MetabolismHepatic, without clinically significant active metabolites
ExcretionRenal
Toxicology & Safety
Harm-reduction note: Toxicity and risk depend on dose, route, purity, combinations, setting, and individual health factors. Missing harms should never be interpreted as evidence of safety.

Not reported

Nitrazepam is a strong, long-acting hypnotic, and its long half-life is the main practical hazard: sedation, impaired coordination, memory and reaction time carry over into the next day and accumulate with nightly use, raising the risk of falls and hip fractures (especially in the elderly) and of impaired driving. Like all benzodiazepines it causes tolerance (its sleep-inducing effect can fade within about a week), physical dependence and, on stopping after regular use, a withdrawal syndrome (rebound insomnia, anxiety, tremor and, after high-dose or abrupt cessation, seizures), so courses are kept short and doses tapered. It can cause respiratory depression, which becomes dangerous when it is combined with opioids, alcohol or other CNS depressants: the usual mechanism of benzodiazepine-related death. It should be avoided or used with great caution in sleep apnoea, severe respiratory insufficiency, myasthenia gravis, severe hepatic impairment and in the elderly, and it is misused recreationally.[2]

Legal Status
Legal note: Legal status can change over time and may vary by country, region, formulation, analogue status, prescription context, and enforcement practice. Always confirm with current official sources before relying on this section.
Interactions & Contraindications

Drug interactions

Opioids Additive respiratory depression and sedation: a leading cause of benzodiazepine-related death (regulatory boxed warnings).[2]
Alcohol, Benzodiazepines, Gabapentinoids (gabapentin, pregabalin) Additive sedation and respiratory depression, including with barbiturates and sedating antihistamines.[2]

Contraindications

Respiratory disease or sleep apnoea sleep apnoea syndrome or severe respiratory insufficiency.[2]
Myasthenia gravis[2]
Kidney or liver impairment severe hepatic impairment.[2]
Combining with alcohol or other CNS depressants concurrent opioids or other CNS depressants without care, with caution in the elderly and in pregnancy.[2]
Usage & Context
  • A hypnotic (sleeping tablet) for the short-term treatment of severe, disabling insomnia: taken at night. Its use has declined in favour of shorter-acting agents because of its next-day carry-over.
  • An anticonvulsant used for myoclonic seizures and infantile spasms (West syndrome) in children, where it is reported to be at least as effective as clonazepam, and occasionally to ease alcohol withdrawal.
  • Also misused recreationally as a sedative. It is a controlled prescription drug.
Sources & Evidence

Further Information