What Are Benzodiazepines & What Types Are There?

Benzodiazepines are prescription medicines that slow activity in the brain and central nervous system, helping reduce anxiety, promote sleep, relax muscles, and control seizures. In the UK, they are usually prescribed short term because of risks such as dependence, tolerance, and withdrawal symptoms. They are classified as controlled drugs and should only be used under close medical supervision, following a GP or specialist’s advice.

What benzodiazepines are

Benzodiazepines are a group of psychoactive medicines that enhance the effect of gamma‑aminobutyric acid (GABA), the main inhibitory neurotransmitter in the brain. By increasing GABA’s calming effect, they reduce excessive brain activity that underlies symptoms such as anxiety, agitation, insomnia, and seizures.

Common reasons they are prescribed include:

• Generalised anxiety and short‑term severe anxiety.
• Panic disorder and acute panic attacks.
• Insomnia, particularly short‑term severe insomnia.
• Seizure disorders and status epilepticus.
• Muscle spasms and spasticity, and alcohol withdrawal in specialist settings.

How benzodiazepines work

Benzodiazepines bind to specific sites on the GABA$_A$A receptor complex in the brain, making GABA more effective at opening chloride channels. This increased chloride flow hyperpolarises neurons, making them less likely to fire and producing sedative, anxiolytic, anticonvulsant, and muscle‑relaxant effects.

Different benzodiazepines vary in:

• Onset of action: how quickly they work (minutes vs hours).
• Duration of action: short, intermediate, or long acting.
• Clinical focus: some are used mainly for insomnia, others for anxiety, seizures, or muscle spasm.

Key safety considerations (UK context)

In UK practice, benzodiazepines are generally recommended for short‑term use (often 2–4 weeks) at the lowest effective dose because of important risks.

Main safety issues:

• Dependence and withdrawal: stopping suddenly after regular use can cause rebound anxiety, insomnia, agitation, and, in severe cases, seizures.
• Tolerance: the effect may lessen over time, tempting dose increases.
• Sedation and falls: especially in older adults, with increased fall and fracture risk.
• Respiratory depression: higher risk if combined with opioids, alcohol, or other sedatives.
• Cognitive effects: drowsiness, poor concentration, and memory problems can affect driving and operating machinery.

Patients are usually advised:

• Not to drive or operate machinery if drowsy or confused.
• To avoid alcohol and non‑prescribed sedatives.
• Never to share medicines and never to alter dose or stop abruptly without medical advice.

Top 10 commonly used benzodiazepines

Below is an overview suitable for UK clinical use. Onset/duration categories are approximate (short, intermediate, long) and focus on typical oral use in adults.

1. Diazepam

• Primary uses (UK)
  • Short‑term relief of severe anxiety and agitation.
  • Muscle spasms (e.g. spinal injury, cerebral palsy) and spasticity.
  • Adjunct in epilepsy and acute seizures; alcohol withdrawal in specialist care.
• Onset and duration
  • Relatively rapid onset (often within 30–60 minutes orally).
  • Long acting, with active metabolites and a prolonged half‑life.
• Key benefits
  • Versatile: anxiolytic, muscle‑relaxant, and anticonvulsant effects.
  • Long duration can smooth symptoms where continuous coverage is needed under supervision.
• Important safety considerations
  • High risk of accumulation and daytime sedation, especially in older adults and those with liver impairment.
  • Dependence risk with regular use; taper slowly if used longer term.

2. Alprazolam

• Primary uses
  • Licensed in some countries for anxiety and panic disorder; used as a high‑potency, short‑acting anxiolytic.
  • In the UK it is not a first‑line choice and availability is more restricted compared with diazepam and lorazepam.
• Onset and duration
  • Fast onset, making it effective for sudden anxiety or panic.
  • Short‑ to intermediate‑acting, often requiring multiple daily doses.
• Key benefits
  • Strong, rapid anxiolytic effect for acute panic symptoms.
  • Useful where brief, targeted symptom control is required under close specialist review.
• Important safety considerations
  • High dependence and withdrawal potential, including rebound anxiety and panic.
  • Not routinely recommended in UK primary care; strict control of dose and duration is essential.

3. Clonazepam

• Primary uses
  • Epilepsy and seizure disorders, including certain complex or treatment‑resistant forms.
  • Panic disorder and severe anxiety in specialist settings.
• Onset and duration
  • Relatively rapid onset.
  • Long‑acting; often dosed once or twice daily.​
• Key benefits
  • Potent anticonvulsant with sustained effect.
  • Long duration can stabilise panic or seizure patterns when used appropriately.​
• Important safety considerations
  • Marked sedation, dizziness, and muscle weakness possible.
  • Dependence and withdrawal may be pronounced; gradual dose reduction required after longer use.

4. Lorazepam

• Primary uses
  • Short‑term treatment of severe anxiety and related insomnia.
  • Acute agitation, status epilepticus, and pre‑procedural sedation (oral, IM, or IV use).​
• Onset and duration
  • Rapid onset, particularly via IV in acute care.
  • Intermediate duration; shorter than diazepam but longer than some short‑acting hypnotics.​
• Key benefits
  • Predictable effect with strong anxiolytic and anticonvulsant actions.
  • Useful when a relatively short course is planned, such as brief crisis management.​
• Important safety considerations
  • Sedation, impaired coordination, and memory disturbance can affect driving and work performance.
  • Should be used for the shortest possible time; higher risk of withdrawal if stopped abruptly.​

5. Temazepam

• Primary uses
  • Short‑term treatment of insomnia, particularly difficulty falling asleep or frequent awakenings.​
• Onset and duration
  • Onset typically within an hour at bedtime.
  • Intermediate‑acting hypnotic; designed to last through the night without very long next‑day effects in most adults.​
• Key benefits
  • Useful for short periods of severe insomnia where non‑drug measures have not been sufficient.
  • Familiar option in UK practice, with well‑known dosing and safety profile.
• Important safety considerations
  • Can cause next‑day drowsiness, reduced alertness, and increased fall risk, especially in older people.
  • Dependence and rebound insomnia can occur; usually restricted to 2–4 weeks’ use.

6. Nitrazepam

• Primary uses
  • Short‑term treatment of severe insomnia, particularly difficulty staying asleep​
• Onset and duration
  • Onset within a few hours of bedtime dosing.
  • Longer‑acting hypnotic; effects can persist into the following day.
• Key benefits
  • Strong hypnotic effect for marked nighttime insomnia.
  • May help when other agents have been ineffective and specialist advice has been sought.
• Important safety considerations
  • High risk of next‑day sedation, confusion, and falls, especially in older adults.
  • Dependence, tolerance, and withdrawal insomnia are major concerns; use is generally limited and closely monitored.

7. Oxazepam

• Primary uses
  • Anxiety and symptoms associated with alcohol withdrawal, often in hospital or specialist community services.
  • Sometimes preferred in liver impairment because of simpler metabolism.
• Onset and duration
  • Slower onset than some other benzodiazepines.
  • Short‑ to intermediate‑acting.​
• Key benefits
  • Lower potency and relatively gentle profile can be helpful in vulnerable patients.
  • Metabolism is less dependent on liver oxidative pathways, which may be advantageous in hepatic disease.
• Important safety considerations
  • Sedation and impaired coordination remain significant risks.
  • Dose should be individually titrated, particularly in older adults and those with comorbidities.

8. Chlordiazepoxide

• Primary uses
  • First‑line benzodiazepine for alcohol withdrawal syndrome in many UK protocols.
  • Short‑term relief of severe anxiety in selected patients.
• Onset and duration
  • Moderate onset.
  • Long‑acting with active metabolites, providing smoother symptom control in alcohol withdrawal regimes.
• Key benefits
  • Long duration helps prevent withdrawal seizures and delirium tremens when used in structured detoxification schedules.
  • Well established in UK clinical guidelines for alcohol withdrawal management.​
• Important safety considerations
  • Accumulation and prolonged sedation, particularly in liver disease and older adults.
  • Use should follow a clear detoxification plan with tapering doses; not intended for routine long‑term anxiety treatment.

9. Clobazam

• Primary uses
  • Adjunctive treatment for epilepsy, including Lennox–Gastaut syndrome and other seizure disorders.
  • Sometimes used for severe anxiety when other options are unsuitable, under specialist care.
• Onset and duration
  • Oral onset over a few hours.
  • Long‑acting, with effects sustained over 24 hours in many patients.
• Key benefits
  • Valuable add‑on anticonvulsant in complex epilepsy.
  • Less sedating for some patients than equivalent doses of other benzodiazepines.
• Important safety considerations
  • Somnolence, dizziness, and behavioural changes can occur.
  • Long‑term use demands regular review to minimise tolerance, dependence, and cognitive side effects.

10. Lormetazepam / Loprazolam (short‑acting hypnotics)

These two medicines are often used in similar ways in UK insomnia practice.

• Primary uses
  • Short‑term treatment of severe insomnia when daytime functioning is significantly impaired.
  • Chosen where a short or intermediate duration is needed.
• Onset and duration
  • Onset within about an hour when taken at bedtime.
  • Short‑ to intermediate‑acting; designed to limit next‑day hangover effects, though these can still occur.​
• Key benefits
  • Targeted hypnotic effect for acute, distressing insomnia.
  • May be preferred to longer‑acting agents in patients who must avoid prolonged next‑day sedation.
• Important safety considerations
  • Drowsiness, confusion, and impaired balance raise fall and accident risk, particularly in older adults.
  • Should only be used for brief periods alongside non‑drug sleep strategies such as sleep hygiene and CBT‑I where available.

Practical points for UK patients

• Benzodiazepines are usually a short‑term option, not a long‑term solution, for anxiety, insomnia, or muscle spasm. Psychological therapies and non‑benzodiazepine medicines are often preferred for ongoing management.
• Any change to dose, or decision to stop, should be discussed with a GP or relevant specialist so that tapering can be planned safely.
• For anxiety and insomnia, UK guidance generally recommends trying non‑drug approaches (such as CBT, relaxation strategies, and sleep hygiene) and non‑benzodiazepine medicines first where appropriate.

Sources

1. https://en.wikipedia.org/wiki/Benzodiazepine
2. https://pmc.ncbi.nlm.nih.gov/articles/PMC8629021/
3. https://www.ncbi.nlm.nih.gov/books/NBK470159/
4. https://pmc.ncbi.nlm.nih.gov/articles/PMC7912725/
5. https://www.priorygroup.com/blog/benzodiazepines-for-anxiety
6. https://my.clevelandclinic.org/health/treatments/24570-benzodiazepines-benzos
7. https://resources.healthgrades.com/right-care/anxiety-disorders/10-drugs-commonly-prescribed-for-anxiety
8. https://www.medicalnewstoday.com/articles/262809
9. https://www.thefreedomcenter.com/these-are-the-strongest-benzodiazepines/
10. https://www.euda.europa.eu/publications/drug-profiles/benzodiazepines_en