Benzodiazepine Pregnancy: Should only be administered to pregnant women if the potential benefits outweigh the risk to the foetus, and during pregnancy only if there is a compelling indication. Anticonvulsants act as teratogens and animal studies show reproductive toxicity; high doses in the last trimester or during labour can cause foetal heart-rate irregularities and neonatal hypothermia, hypotonia, mild respiratory depression and poor feeding, and neonates may develop withdrawal symptoms after chronic maternal use. Both pregnancy itself and abrupt discontinuation can exacerbate epilepsy. Breast-feeding: mothers undergoing treatment should not breastfeed; if there is a compelling indication, breastfeeding should be discontinued.

Clonazepam

Brand names: Rivotril

Clonazepam is a long-acting benzodiazepine used for certain seizure types and selected other indications.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Initial dosage should not exceed 1 mg/day; the maintenance dosage for adults normally falls within the range 4 to 8 mg

Route: Oral

Frequency: Total daily dosage divided into 3 or 4 doses taken at intervals throughout the day; if doses are not equally divided the largest dose should be given before retiring. Once the maintenance dose level has been reached, the daily amount may be given as a single dose in the evening

Max: If necessary, larger doses may be given at the discretion of the physician, up to a maximum of 20 mg daily

Treatment should be started with low doses and increased progressively until the maintenance dose suited to the individual patient has been found; the maintenance dose should be attained after 2 to 4 weeks of treatment and must be determined according to clinical response and tolerance. Before starting, agree a strategy for ending treatment to minimise the risk of dependence, addiction and drug withdrawal syndrome; treatment should be given for the shortest possible duration, but as this medicine is used for epilepsy it should be used for as long as the prescriber considers necessary. Do not interrupt treatment abruptly — withdraw by gradually reducing the dose because of the risk of precipitating status epilepticus. ELDERLY: particularly sensitive to centrally depressant drugs and may experience confusion — initial dose should not exceed 0.5 mg/day. HEPATIC IMPAIRMENT: patients with severe hepatic impairment should not be treated with clonazepam; in mild to moderate hepatic impairment the dose should be adjusted to individual requirements and will probably be lower. Simultaneous administration of more than one antiepileptic drug may be undertaken with clonazepam, with dose adjustment of each drug as required; multiple anticonvulsants may increase undesired effects. If status epilepticus occurs in a patient receiving oral clonazepam, intravenous clonazepam may still control the status. PAEDIATRIC (eMC age bands — no per-kg rule stated): to ensure optimum dosage adjustment children should be given the 0.5 mg tablets; initial dosage should not exceed 0.25 mg/day for infants and small children (1 to 5 years) and 0.5 mg/day for older children; maintenance dosage normally falls within the ranges infants (0 to 1 year) 0.5 to 1 mg/day, small children (1 to 5 years) 1 to 3 mg/day, school children (5 to 12 years) 3 to 6 mg/day. In some forms of childhood epilepsy control may be re-established by increasing the dose or interrupting treatment for 2 or 3 weeks under careful observation. Because the SPC gives age bands rather than a per-kg rule, no structured paediatric dose is recorded here — verify all paediatric dosing against a children's formulary. Source: eMC SPC for Clonazepam Aristo 0.5 mg Tablets (§4.2).

Dose adjustments

Renal

Use with caution in patients with impairment of renal function — in such cases dosage should generally be reduced (no numeric renal dose given in the SPC).

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

DOSAGE AND ADMINISTRATION Clonazepam is available as a tablet. The tablets should be administered with water by swallowing the tablet whole. Seizure Disorders: The use of multiple anticonvulsants may result in an increase of CNS depressant adverse effects. This should be considered before adding clonazepam tablets to an existing anticonvulsant regimen. Adults: The initial dose for adults with seizure disorders should not exceed 1.5 mg/day divided into three doses. Dosage may be increased in increments of 0.5 mg to 1 mg every 3 days until seizures are adequately controlled or until side effects preclude any further increase. Maintenance dosage must be individualized for each patient …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2026-03-16. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

Known hypersensitivity to benzodiazepines, or to the active substance or any of the excipients
Acute pulmonary insufficiency; severe respiratory insufficiency
Sleep apnoea syndrome
Myasthenia gravis
Severe hepatic insufficiency
Must not be used in patients in a coma, or in patients known to be abusing pharmaceuticals, drugs or alcohol

Side effects

Somnolence, slowed reaction, muscular hypotonia, dizziness and ataxia — occur relatively frequently, usually transient, and can be partially prevented by increasing the dose slowly at the start of treatment
Anterograde amnesia at therapeutic doses (risk increases at higher doses), which may be associated with inappropriate behaviour; drug dependence
Impaired concentration, restlessness, confusional state, disorientation and depression; paradoxical reactions such as excitability, irritability, aggression, agitation, nervousness, hostility, anxiety, sleep disturbances, nightmares and psychotic disorders, with activation of new types of seizures
Reversible dysarthria, reduced coordination, gait disorder, nystagmus (common) and diplopia, particularly in long-term or high-dose treatment; increased seizure frequency with certain forms of epilepsy during long-term treatment
Respiratory depression (rare, particularly on intravenous administration, aggravated by pre-existing airways obstruction or brain damage); cardiac failure including cardiac arrest has been reported
Allergic reactions with very rare anaphylaxis and rare angioedema; isolated cases of reversible incomplete precocious puberty in children

Interactions

Alcohol and CNS depressants — concomitant use should be avoided; potential for severe sedation and clinically relevant respiratory and/or cardiovascular depression (SPC §4.4)
Opioids — concomitant use may result in sedation, respiratory depression, coma and death; reserve concomitant prescribing for patients with no alternative and limit dose and duration (SPC §4.4)
Other centrally acting medications and anticonvulsant (antiepileptic) agents — dosage must be carefully adjusted to individual requirements; multiple anticonvulsants may increase undesired effects (SPC §4.2/§4.4)
Drugs which depress respiration — respiratory effects may be aggravated (SPC §4.4)
Phenytoin — clonazepam has the potential to influence phenytoin concentrations; monitoring of phenytoin concentration is recommended on co-administration (US labelling, Drug Interactions)
Full eMC §4.5 was not captured in the fetched source — verify the complete interaction section

Clinical monograph

How it works

It enhances the inhibitory action of GABA at the GABA-A receptor, increasing neuronal inhibition.

Prescribing in practice

Sedation, tolerance and dependence limit it — use the lowest effective dose for the shortest appropriate time.
Dangerous respiratory depression can occur with opioids or alcohol.
Do not stop it abruptly (risk of withdrawal seizures); it causes falls and confusion in older people.

Monitoring

Review the ongoing need regularly, along with sedation, mood and signs of dependence.

Counselling the patient

Do not stop it suddenly.
Avoid alcohol; it is dangerous combined with opioid painkillers.
It impairs driving and operating machinery.

Evidence & guidelines

Used for specific epilepsy indications and selected other uses, mindful of dependence (NICE NG217).

Reference: NICE NG217; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

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