Some loss of effect may occur during the course of clonazepam long-term treatment.
Prolonged use of benzodiazepines may result in dependence development with withdrawal symptoms on cessation of use.
Clonazepam should be used with caution in patients with chronic pulmonary insufficiency, or with impairment of renal or hepatic function, and in the elderly or the debilitated. In these cases, dosage should generally be reduced.
In cases of loss or bereavement, psychological adjustment may be inhibited by benzodiazepines.
Hepatic impairment
Benzodiazepines may have a contributory role in precipitating episodes of hepatic encephalopathy in severe hepatic impairment. Special caution should be exercised when administering Clonazepam to patients with mild to moderate hepatic impairment (see section 4.3).
Central Nervous System (CNS), psychosis and depression
Clonazepam should be used with particular caution in patients with ataxia.
Benzodiazepines are not recommended for the primary treatment of psychotic illness.
Patients with a history of depression and/or suicide attempts should be kept under close supervision.
Suicidal ideation and behaviour have been reported in patients treated with anti-epileptic agents in several indications. A meta-analysis of randomised placebo controlled trials of anti-epileptic drugs has also shown a small increased risk of suicidal ideation and behaviour. The mechanism of this risk is not known and the available data do not exclude the possibility of an increased risk for clonazepam.
Therefore patients should be monitored for signs of suicidal ideation and behaviours and appropriate treatment should be considered. Patients (and caregivers of patients) should be advised to seek medical advice should signs of suicidal ideation or behaviour emerge.
Concomitant use of alcohol / CNS depressants
The concomitant use of Clonazepam with alcohol or/and CNS depressants should be avoided. Such concomitant use has the potential to increase the clinical effects of Clonazepam possibly including severe sedation that could result in coma or death, clinically relevant respiratory and/or cardio-vascular depression (see section 4.5 and 4.9).
Clonazepam should be used with particular caution in the event of acute intoxication with alcohol or drugs.
Psychiatric and 'paradoxical' reactions
Paradoxical reactions such as restlessness, agitation, irritability, aggressiveness, anxiety, delusion, anger, nightmares, hallucinations, psychoses, inappropriate behaviour and other adverse behavioural effects are known to occur when using benzodiazepines (see section 4.8). Should this occur, the use of the drug should be discontinued. Paradoxical reactions are more likely to occur in children and in the elderly.
Amnesia
The risk of anterograde amnesia, which may occur using benzodiazepines at therapeutic dosages, increases at higher dosages. Amnestic effects may be associated with inappropriate behaviour. With certain forms of epilepsy, an increase in the frequency of seizures (see 4.8) during long-term treatment is possible.
Sleep apnoea
Benzodiazepines are not recommended for use in patients with sleep apnoea due to possible additive effects on respiratory depression (see section 4.3).
Respiratory disorders
The dosage of Clonazepam must be carefully adjusted to individual requirements in patients with pre-existing disease of the respiratory system (e.g. chronic obstructive pulmonary disease). Effects on the respiratory system may be aggravated by pre-existing airways obstruction or brain damage or if other medications which depress respiration have been given. As a rule, this effect can be avoided by careful adjustment of the dose to individual requirements.
Epilepsy
The dosage of Clonazepam must be carefully adjusted to individual requirements in patients undergoing treatment with other centrally acting medications or anticonvulsant (antiepileptic) agents (see section 4.5).
As with all other antiepileptic drugs, treatment with clonazepam even if of short duration, must not be abruptly interrupted, but must be withdrawn by gradually reducing the dose in view of the risk of precipitating status epilepticus. In such cases a combination with other antiepileptics is indicated. This precaution must also be taken when withdrawing another drug while the patient is still receiving clonazepam therapy.
Porphyria
Clonazepam is considered to be probably nonporphyrinogenic, although there is some conflicting evidence. Therefore, in patients with porphyria, clonazepam should be used with care.
Paediatric population
In infants and small children Clonazepam may cause increased production of saliva and bronchial secretion. Therefore, special attention must be paid to maintaining patency of the airways.
Elderly
Benzodiazepine pharmacologic effects appear to be greater in elderly patients than in younger patients even at similar plasma benzodiazepine concentrations, possibly because of age-related changes in drug–receptor interactions, post-receptor mechanisms and organ function.
Dependence
Use of benzodiazepines may lead to the development of physical and psychological dependence upon these products (see section 4.8). In particular long-term or high-dose treatment, may lead to reversible disorders such as dysarthria, reduced coordination of movements and gait disorder (ataxia), nystagmus and vision (diplopia).
The risk of dependence increases with dose and duration of treatment; it is also greater in patients with a medical history of alcoholism and/or drug abuse. Abuse has been reported in poly-drug abusers.
Clonazepam should be used with extreme caution in patients with a history of alcohol or drug abuse.
Once physical dependence has developed, abrupt termination of treatment will be accompanied by withdrawal symptoms. During long-term treatment, withdrawal symptoms may develop after a lengthy period of use, especially with high doses or if the daily dose is reduced rapidly or abruptly discontinued. The symptoms include tremor, sweating, agitation, sleep disturbances and anxiety, headaches, diarrhoea, muscle pain, extreme anxiety, tension, restlessness, mood changes, confusion, irritability and epileptic seizures which may be associated with the underlying disease. In severe cases the following symptoms may occur: derealisation, depersonalisation, hyperacusis, numbness and tingling of the extremities, hypersensitivity to light, noise and physical contact or hallucinations. Since the risk of withdrawal symptoms is greater after abrupt discontinuation of treatment, abrupt withdrawal of the drug should therefore be avoided and treatment - even if only of short duration - should be terminated by gradually reducing the daily dose. The risk of withdrawal symptoms is increased when benzodiazepines are used together with day-time sedatives (crossed tolerance).
Risk from concomitant use of opioids:
Concomitant use of Clonazepam Thame and opioids may result in sedation, respiratory depression, coma and death. Because of these risks, concomitant prescribing of sedative medicines such as benzodiazepines or related drugs such as Clonazepam Thame with opioids should be reserved for patients for whom alternative treatment options are not possible. If a decision is made to prescribe Clonazepam Thame concomitantly with opioids, the lowest effective dose should be used, and the duration of treatment should be as short as possible (see also general dose recommendation in section 4.2).
The patients should be followed closely for signs and symptoms of respiratory depression and sedation. In this respect, it is strongly recommended to inform patients and their caregivers (where applicable) to be aware of these symptoms (see section 4.5).
Excipient warnings:
This medicine contains 64.68mg of alcohol (ethanol) in each 5ml which is equivalent to 64.68mg of ethanol (96%) per 5ml dose. The amount in 5ml of this medicine is equivalent to less than 2 ml beer or 1 ml wine.
The small amount of alcohol in this medicine will not have any noticeable effects.