Data from FDA (Food and Drug Administration, USA) - Curated by EPG Health - Last updated 18 December 2019

Indication(s)

INDICATIONS AND USAGE Seizure Disorders Klonopin is useful alone or as an adjunct in the treatment of the Lennox-Gastaut syndrome (petit mal variant), akinetic and myoclonic seizures. In patients with absence seizures (petit mal) who have failed to respond to succinimides, Klonopin may be useful. Some loss of effect may occur during the course of clonazepam treatment (see PRECAUTIONS: Loss of Effect). Panic Disorder Klonopin is indicated for the treatment of panic disorder, with or without agoraphobia, as defined in DSM-V. Panic disorder is characterized by the occurrence of unexpected panic attacks and associated concern about having additional attacks, worry about the implications or consequences of the attacks, and/or a significant change in behavior related to the attacks. The efficacy of Klonopin was established in two 6- to 9-week trials in panic disorder patients whose diagnoses corresponded to the DSM-IIIR category of panic disorder (see CLINICAL PHARMACOLOGY: Clinical Trials). Panic disorder (DSM-V) is characterized by recurrent unexpected panic attacks, ie, a discrete period of intense fear or discomfort in which four (or more) of the following symptoms develop abruptly and reach a peak within 10 minutes: (1) palpitations, pounding heart or accelerated heart rate; (2) sweating; (3) trembling or shaking; (4) sensations of shortness of breath or smothering; (5) feeling of choking; (6) chest pain or discomfort; (7) nausea or abdominal distress; (8) feeling dizzy, unsteady, lightheaded or faint; (9) derealization (feelings of unreality) or depersonalization (being detached from oneself); (10) fear of losing control; (11) fear of dying; (12) paresthesias (numbness or tingling sensations); (13) chills or hot flushes. The effectiveness of Klonopin in long-term use, that is, for more than 9 weeks, has not been systematically studied in controlled clinical trials. The physician who elects to use Klonopin for extended periods should periodically reevaluate the long-term usefulness of the drug for the individual patient (see DOSAGE AND ADMINISTRATION).

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Advisory information

contraindications
CONTRAINDICATIONS Klonopin is contraindicated in patients with the following conditions: History of sensitivity to benzodiazepines Clinical or biochemical evidence of significant liver disease Acute narrow angle glaucoma (it may be used in patients with open angle glaucoma who are receiving appropriate therapy).
Special warnings and precautions
PRECAUTIONS General Worsening of Seizures When used in patients in whom several different types of seizure disorders coexist, Klonopin may increase the incidence or precipitate the onset of generalized tonic-clonic seizures (grand mal). This may require the addition of appropriate anticonvulsants or an increase in their dosages. The concomitant use of valproic acid and Klonopin may produce absence status. Loss of Effect In some studies, up to 30% of patients who initially responded have shown a loss of anticonvulsant activity, often within 3 months of administration. In some cases, dosage adjustment may reestablish efficacy. Laboratory Testing During Long-Term Therapy Periodic blood counts and liver function tests are advisable during long-term therapy with Klonopin. Psychiatric and Paradoxical Reactions Paradoxical reactions, such as agitation, irritability, aggression, anxiety, anger, nightmares, hallucinations, and psychoses are known to occur when using benzodiazepines (see ADVERSE REACTIONS: Psychiatric). Should this occur, the use of the drug should be discontinued gradually (see PRECAUTIONS: Risks of Abrupt Withdrawal and DRUG ABUSE AND DEPENDENCE: Physical and Psychological Dependence). Paradoxical reactions are more likely to occur in children and in the elderly. Risks of Abrupt Withdrawal The abrupt withdrawal of Klonopin, particularly in those patients on long-term, high-dose therapy, may precipitate status epilepticus. Therefore, when discontinuing Klonopin, gradual withdrawal is essential. While Klonopin is being gradually withdrawn, the simultaneous substitution of another anticonvulsant may be indicated. Caution in Renally Impaired Patients Metabolites of Klonopin are excreted by the kidneys; to avoid their excess accumulation, caution should be exercised in the administration of the drug to patients with impaired renal function. Hypersalivation Klonopin may produce an increase in salivation. This should be considered before giving the drug to patients who have difficulty handling secretions. Respiratory Depression Klonopin may cause respiratory depression and should be used with caution in patients with compromised respiratory function (e.g., chronic obstructive pulmonary disease, sleep apnea). Porphyria Klonopin may have a porphyrogenic effect and should be used with care in patients with porphyria. Information for Patients A Klonopin Medication Guide must be given to the patient each time Klonopin is dispensed, as required by law. Patients should be instructed to take Klonopin only as prescribed. Physicians are advised to discuss the following issues with patients for whom they prescribe Klonopin: Risks from Concomitant Use with Opioids Inform patients and caregivers that potentially fatal additive effects may occur if Klonopin is used with opioids and not to use such drugs concomitantly unless supervised by a health care provider (see WARNINGS: Risks from Concomitant Use with Opioids and PRECAUTIONS: Drug Interactions). Dose Changes To assure the safe and effective use of benzodiazepines, patients should be informed that, since benzodiazepines may produce psychological and physical dependence, it is advisable that they consult with their physician before either increasing the dose or abruptly discontinuing this drug. Interference With Cognitive and Motor Performance Because benzodiazepines have the potential to impair judgment, thinking or motor skills, patients should be cautioned about operating hazardous machinery, including automobiles, until they are reasonably certain that Klonopin therapy does not affect them adversely. Suicidal Thinking and Behavior Patients, their caregivers, and families should be counseled that AEDs, including Klonopin, may increase the risk of suicidal thoughts and behavior and should be advised of the need to be alert for the emergence or worsening of symptoms of depression, any unusual changes in mood or behavior, or the emergence of suicidal thoughts, behavior, or thoughts about self-harm. Behaviors of concern should be reported immediately to healthcare providers. Pregnancy Patients should be advised to notify their physician if they become pregnant or intend to become pregnant during therapy with Klonopin (see PRECAUTIONS: Pregnancy). Patients should be encouraged to enroll in the North American Antiepileptic Drug (NAAED) Pregnancy Registry if they become pregnant. This registry is collecting information about the safety of antiepileptic drugs during pregnancy. To enroll, patients can call the toll free number 1-888-233-2334 (see PRECAUTIONS: Pregnancy). Nursing Patients should be advised to notify their physician if they are breastfeeding or intend to breastfeed during therapy. Concomitant Medication Patients should be advised to inform their physicians if they are taking, or plan to take, any prescription or over-the-counter drugs, since there is a potential for interactions. Alcohol Patients should be advised to avoid alcohol while taking Klonopin. Drug Interactions Effect of Concomitant Use of Benzodiazepines and Opioids The concomitant use of benzodiazepines and opioids increases the risk of respiratory depression because of actions at different receptor sites in the CNS that control respiration. Benzodiazepines interact at GABAA sites, and opioids interact primarily at mu receptors. When benzodiazepines and opioids are combined, the potential for benzodiazepines to significantly worsen opioid-related respiratory depression exists. Limit dosage and duration of concomitant use of benzodiazepines and opioids, and follow patients closely for respiratory depression and sedation. Effect of Clonazepam on the Pharmacokinetics of Other Drugs Clonazepam does not appear to alter the pharmacokinetics of phenytoin, carbamazepine or phenobarbital. Clonazepam has the potential to influence concentrations of phenytoin. Monitoring of phenytoin concentration is recommended when clonazepam is co-administrated with phenytoin. The effect of clonazepam on the metabolism of other drugs has not been investigated. Effect of Other Drugs on the Pharmacokinetics of Clonazepam Literature reports suggest that ranitidine, an agent that decreases stomach acidity, does not greatly alter clonazepam pharmacokinetics. In a study in which the 2 mg clonazepam orally disintegrating tablet was administered with and without propantheline (an anticholinergic agent with multiple effects on the GI tract) to healthy volunteers, the AUC of clonazepam was 10% lower and the Cmax of clonazepam was 20% lower when the orally disintegrating tablet was given with propantheline compared to when it was given alone. The selective serotonin reuptake inhibitors sertraline (weak CYP3A4 inducer) and fluoxetine (CYP2D6 inhibitor), and the anti-epileptic drug felbamate (CYP2C19 inhibitor and CYP3A4 inducer) do not affect the pharmacokinetics of clonazepam. Cytochrome P-450 inducers, such as phenytoin, carbamazepine, lamotrigine, and phenobarbital induce clonazepam metabolism, causing an approximately 38% decrease in plasma clonazepam levels. Although clinical studies have not been performed, based on the involvement of the cytochrome P-450 3A family in clonazepam metabolism, inhibitors of this enzyme system, notably oral antifungal agents (e.g., fluconazole), should be used cautiously in patients receiving clonazepam because they may impair the metabolism of clonazepam leading to exaggerated concentrations and effects. Pharmacodynamic Interactions The CNS-depressant action of the benzodiazepine class of drugs may be potentiated by alcohol, narcotics, barbiturates, nonbarbiturate hypnotics, antianxiety agents, the phenothiazines, thioxanthene and butyrophenone classes of antipsychotic agents, monoamine oxidase inhibitors and the tricyclic antidepressants, and by other anticonvulsant drugs. Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenesis Carcinogenicity studies have not been conducted with clonazepam. Mutagenesis The data currently available are not sufficient to determine the genotoxic potential of clonazepam. Impairment of Fertility In a two-generation fertility study in which clonazepam was given orally to rats at 10 and 100 mg/kg/day, there was a decrease in the number of pregnancies and in the number of offspring surviving until weaning. The lowest dose tested is approximately 5 and 24 times the maximum recommended human dose (MRHD) of 20 mg/day for seizure disorders and 4 mg/day for panic disorder, respectively, on a body surface area (mg/m2) basis. Pregnancy There are no adequate and well-controlled studies of Klonopin in pregnant women. Available human data on the risk of teratogenicity are inconclusive. There is insufficient evidence in humans to assess the effect of benzodiazepine exposure during pregnancy on neurodevelopment. Administration of benzodiazepines immediately prior to or during childbirth can result in a syndrome of hypothermia, hypotonia, respiratory depression, and difficulty feeding. In addition, infants born to mothers who have taken benzodiazepines during the later stages of pregnancy can develop dependence, and subsequently withdrawal, during the postnatal period. In three studies in which clonazepam was administered orally to pregnant rabbits at doses of 0.2, 1, 5, or 10 mg/kg/day during the period of organogenesis, a similar pattern of malformations (cleft palate, open eyelid, fused sternebrae and limb defects) was observed at all doses, in a low, non-dose-related incidence. The lowest dose tested is less than the maximum recommended human dose (MRHD) of 20 mg/day for seizure disorders and similar to the MRHD of 4 mg/day for panic disorder, on a mg/m2 basis. Reductions in maternal weight gain occurred at doses of 5 mg/kg/day or greater and reduction in embryofetal growth occurred in one study at a dose of 10 mg/kg/day. No adverse maternal or embryofetal effects were observed in mice or rats following oral administration of clonazepam during organogenesis of doses up to 15 or 40 mg/kg/day, respectively (4 and 20 times the MRHD of 20 mg/day for seizure disorders and 20 and 100 times the MRHD of 4 mg/day for panic disorder, respectively, on a mg/m2 basis). Data for other benzodiazepines suggest the possibility of adverse developmental effects (long-term effects on neurobehavioral and immunological function) in animals following prenatal exposure to benzodiazepines. To provide information regarding the effects of in utero exposure to Klonopin, physicians are advised to recommend that pregnant patients taking Klonopin enroll in the NAAED Pregnancy Registry. This can be done by calling the toll free number 1-888-233-2334, and must be done by patients themselves. Information on this registry can also be found at the website http://www.aedpregnancyregistry.org/. Labor and Delivery The effect of Klonopin on labor and delivery in humans has not been specifically studied; however, perinatal complications have been reported in children born to mothers who have been receiving benzodiazepines late in pregnancy, including findings suggestive of either excess benzodiazepine exposure or of withdrawal phenomena (see WARNINGS: Pregnancy Risks). Nursing Mothers The effects of Klonopin on the breastfed infant and on milk production are unknown. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for Klonopin and any potential adverse effects on the breastfed infant from Klonopin or from the underlying maternal condition. Pediatric Use Because of the possibility that adverse effects on physical or mental development could become apparent only after many years, a benefit-risk consideration of the long-term use of Klonopin is important in pediatric patients being treated for seizure disorder (see INDICATIONS AND USAGE and DOSAGE AND ADMINISTRATION). Safety and effectiveness in pediatric patients with panic disorder below the age of 18 have not been established. Geriatric Use Clinical studies of Klonopin did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. Because clonazepam undergoes hepatic metabolism, it is possible that liver disease will impair clonazepam elimination. Metabolites of Klonopin are excreted by the kidneys; to avoid their excess accumulation, caution should be exercised in the administration of the drug to patients with impaired renal function. Because elderly patients are more likely to have decreased hepatic and/or renal function, care should be taken in dose selection, and it may be useful to assess hepatic and/or renal function at the time of dose selection. Sedating drugs may cause confusion and over-sedation in the elderly; elderly patients generally should be started on low doses of Klonopin and observed closely.
Adverse reactions
ADVERSE REACTIONS The adverse experiences for Klonopin are provided separately for patients with seizure disorders and with panic disorder. Seizure Disorders The most frequently occurring side effects of Klonopin are referable to CNS depression. Experience in treatment of seizures has shown that drowsiness has occurred in approximately 50% of patients and ataxia in approximately 30%. In some cases, these may diminish with time; behavior problems have been noted in approximately 25% of patients. Others, listed by system, including those identified during postapproval use of Klonopin are: Cardiovascular: Palpitations Dermatologic: Hair loss, hirsutism, skin rash, ankle and facial edema Gastrointestinal: Anorexia, coated tongue, constipation, diarrhea, dry mouth, encopresis, gastritis, increased appetite, nausea, sore gums Genitourinary: Dysuria, enuresis, nocturia, urinary retention Hematopoietic: Anemia, leukopenia, thrombocytopenia, eosinophilia Hepatic: Hepatomegaly, transient elevations of serum transaminases and alkaline phosphatase Musculoskeletal: Muscle weakness, pains Miscellaneous: Dehydration, general deterioration, fever, lymphadenopathy, weight loss or gain Neurologic: Abnormal eye movements, aphonia, choreiform movements, coma, diplopia, dysarthria, dysdiadochokinesis, ''glassy-eyed'' appearance, headache, hemiparesis, hypotonia, nystagmus, respiratory depression, slurred speech, tremor, vertigo Psychiatric: Confusion, depression, amnesia, hallucinations, hysteria, increased libido, insomnia, psychosis (the behavior effects are more likely to occur in patients with a history of psychiatric disturbances). The following paradoxical reactions have been observed: irritability, aggression, agitation, nervousness, hostility, anxiety, sleep disturbances, nightmares, abnormal dreams, hallucinations. Respiratory: Chest congestion, rhinorrhea, shortness of breath, hypersecretion in upper respiratory passages Panic Disorder Adverse events during exposure to Klonopin were obtained by spontaneous report and recorded by clinical investigators using terminology of their own choosing. Consequently, it is not possible to provide a meaningful estimate of the proportion of individuals experiencing adverse events without first grouping similar types of events into a smaller number of standardized event categories. In the tables and tabulations that follow, CIGY dictionary terminology has been used to classify reported adverse events, except in certain cases in which redundant terms were collapsed into more meaningful terms, as noted below. The stated frequencies of adverse events represent the proportion of individuals who experienced, at least once, a treatment-emergent adverse event of the type listed. An event was considered treatment-emergent if it occurred for the first time or worsened while receiving therapy following baseline evaluation. Adverse Findings Observed in Short-Term, Placebo-Controlled Trials Adverse Events Associated with Discontinuation of Treatment Overall, the incidence of discontinuation due to adverse events was 17% in Klonopin compared to 9% for placebo in the combined data of two 6- to 9-week trials. The most common events (≥1%) associated with discontinuation and a dropout rate twice or greater for Klonopin than that of placebo included the following: Table 2 Most Common Adverse Events (≥1%) Associated with Discontinuation of Treatment Adverse Event Klonopin (N=574) Placebo (N=294) Somnolence 7% 1% Depression 4% 1% Dizziness 1% <1% Nervousness 1% 0% Ataxia 1% 0% Intellectual Ability Reduced 1% 0% Adverse Events Occurring at an Incidence of 1% or More among Klonopin-Treated Patients Table 3 enumerates the incidence, rounded to the nearest percent, of treatment-emergent adverse events that occurred during acute therapy of panic disorder from a pool of two 6- to 9-week trials. Events reported in 1% or more of patients treated with Klonopin (doses ranging from 0.5 to 4 mg/day) and for which the incidence was greater than that in placebo-treated patients are included. The prescriber should be aware that the figures in Table 3 cannot be used to predict the incidence of side effects in the course of usual medical practice where patient characteristics and other factors differ from those that prevailed in the clinical trials. Similarly, the cited frequencies cannot be compared with figures obtained from other clinical investigations involving different treatments, uses and investigators. The cited figures, however, do provide the prescribing physician with some basis for estimating the relative contribution of drug and nondrug factors to the side effect incidence in the population studied. Table 3 Treatment-Emergent Adverse Event Incidence in 6- to 9-Week Placebo-Controlled Clinical TrialsEvents reported by at least 1% of patients treated with Klonopin and for which the incidence was greater than that for placebo. Clonazepam Maximum Daily Dose Adverse Event by Body System <1mg n=96 % 1-<2mg n=129 % 2-<3mg n=113 % ≥3mg n=235 % All Klonopin Groups N=574 % Placebo N=294 % Central & Peripheral Nervous System SomnolenceIndicates that the p-value for the dose-trend test (Cochran-Mantel-Haenszel) for adverse event incidence was ≤0.10. 26 35 50 36 37 10 Dizziness 5 5 12 8 8 4 Coordination Abnormal 1 2 7 9 6 0 Ataxia 2 1 8 8 5 0 Dysarthria 0 0 4 3 2 0 Psychiatric Depression 7 6 8 8 7 1 Memory Disturbance 2 5 2 5 4 2 Nervousness 1 4 3 4 3 2 Intellectual Ability Reduced 0 2 4 3 2 0 Emotional Lability 0 1 2 2 1 1 Libido Decreased 0 1 3 1 1 0 Confusion 0 2 2 1 1 0 Respiratory System Upper Respiratory Tract Infection 10 10 7 6 8 4 Sinusitis 4 2 8 4 4 3 Rhinitis 3 2 4 2 2 1 Coughing 2 2 4 0 2 0 Pharyngitis 1 1 3 2 2 1 Bronchitis 1 0 2 2 1 1 Gastrointestinal System Constipation 0 1 5 3 2 2 Appetite Decreased 1 1 0 3 1 1 Abdominal Pain 2 2 2 0 1 1 Body as a Whole Fatigue 9 6 7 7 7 4 Allergic Reaction 3 1 4 2 2 1 Musculoskeletal Myalgia 2 1 4 0 1 1 Resistance Mechanism Disorders Influenza 3 2 5 5 4 3 Urinary System Micturition Frequency 1 2 2 1 1 0 Urinary Tract Infection 0 0 2 2 1 0 Vision Disorders Blurred Vision 1 2 3 0 1 1 Reproductive DisordersDenominators for events in gender-specific systems are: n=240 (clonazepam), 102 (placebo) for male, and 334 (clonazepam), 192 (placebo) for female. Female Dysmenorrhea 0 6 5 2 3 2 Colpitis 4 0 2 1 1 1 Male Ejaculation Delayed 0 0 2 2 1 0 Impotence 3 0 2 1 1 0 Commonly Observed Adverse Events Table 4 Incidence of Most Commonly Observed Adverse EventsTreatment-emergent events for which the incidence in the clonazepam patients was ≥5% and at least twice that in the placebo patients. in Acute Therapy in Pool of 6- to 9-Week Trials Adverse Event Clonazepam (N=574) Placebo (N=294) Somnolence 37% 10% Depression 7% 1% Coordination Abnormal 6% 0% Ataxia 5% 0% Treatment-Emergent Depressive Symptoms In the pool of two short-term placebo-controlled trials, adverse events classified under the preferred term "depression" were reported in 7% of Klonopin-treated patients compared to 1% of placebo-treated patients, without any clear pattern of dose relatedness. In these same trials, adverse events classified under the preferred term "depression" were reported as leading to discontinuation in 4% of Klonopin-treated patients compared to 1% of placebo-treated patients. While these findings are noteworthy, Hamilton Depression Rating Scale (HAM-D) data collected in these trials revealed a larger decline in HAM-D scores in the clonazepam group than the placebo group suggesting that clonazepam-treated patients were not experiencing a worsening or emergence of clinical depression. Other Adverse Events Observed During the Premarketing Evaluation of Klonopin in Panic Disorder Following is a list of modified CIGY terms that reflect treatment-emergent adverse events reported by patients treated with Klonopin at multiple doses during clinical trials. All reported events are included except those already listed in Table 3 or elsewhere in labeling, those events for which a drug cause was remote, those event terms which were so general as to be uninformative, and events reported only once and which did not have a substantial probability of being acutely life-threatening. It is important to emphasize that, although the events occurred during treatment with Klonopin, they were not necessarily caused by it. Events are further categorized by body system and listed in order of decreasing frequency. These adverse events were reported infrequently, which is defined as occurring in 1/100 to 1/1000 patients. Body as a Whole: weight increase, accident, weight decrease, wound, edema, fever, shivering, abrasions, ankle edema, edema foot, edema periorbital, injury, malaise, pain, cellulitis, inflammation localized Cardiovascular Disorders: chest pain, hypotension postural Central and Peripheral Nervous System Disorders: migraine, paresthesia, drunkenness, feeling of enuresis, paresis, tremor, burning skin, falling, head fullness, hoarseness, hyperactivity, hypoesthesia, tongue thick, twitching Gastrointestinal System Disorders: abdominal discomfort, gastrointestinal inflammation, stomach upset, toothache, flatulence, pyrosis, saliva increased, tooth disorder, bowel movements frequent, pain pelvic, dyspepsia, hemorrhoids Hearing and Vestibular Disorders: vertigo, otitis, earache, motion sickness Heart Rate and Rhythm Disorders: palpitation Metabolic and Nutritional Disorders: thirst, gout Musculoskeletal System Disorders: back pain, fracture traumatic, sprains and strains, pain leg, pain nape, cramps muscle, cramps leg, pain ankle, pain shoulder, tendinitis, arthralgia, hypertonia, lumbago, pain feet, pain jaw, pain knee, swelling knee Platelet, Bleeding and Clotting Disorders: bleeding dermal Psychiatric Disorders: insomnia, organic disinhibition, anxiety, depersonalization, dreaming excessive, libido loss, appetite increased, libido increased, reactions decreased, aggression, apathy, disturbance in attention, excitement, anger, hunger abnormal, illusion, nightmares, sleep disorder, suicide ideation, yawning Reproductive Disorders, Female: breast pain, menstrual irregularity Reproductive Disorders, Male: ejaculation decreased Resistance Mechanism Disorders: infection mycotic, infection viral, infection streptococcal, herpes simplex infection, infectious mononucleosis, moniliasis Respiratory System Disorders: sneezing excessive, asthmatic attack, dyspnea, nosebleed, pneumonia, pleurisy Skin and Appendages Disorders: acne flare, alopecia, xeroderma, dermatitis contact, flushing, pruritus, pustular reaction, skin burns, skin disorder Special Senses Other, Disorders: taste loss Urinary System Disorders: dysuria, cystitis, polyuria, urinary incontinence, bladder dysfunction, urinary retention, urinary tract bleeding, urine discoloration Vascular (Extracardiac) Disorders: thrombophlebitis leg Vision Disorders: eye irritation, visual disturbance, diplopia, eye twitching, styes, visual field defect, xerophthalmia

Usage information

Dosing and administration
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 Klonopin 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 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 depending upon response. Maximum recommended daily dose is 20 mg. Pediatric Patients Klonopin is administered orally. In order to minimize drowsiness, the initial dose for infants and children (up to 10 years of age or 30 kg of body weight) should be between 0.01 and 0.03 mg/kg/day but not to exceed 0.05 mg/kg/day given in two or three divided doses. Dosage should be increased by no more than 0.25 to 0.5 mg every third day until a daily maintenance dose of 0.1 to 0.2 mg/kg of body weight has been reached, unless seizures are controlled or side effects preclude further increase. Whenever possible, the daily dose should be divided into three equal doses. If doses are not equally divided, the largest dose should be given before retiring. Geriatric Patients There is no clinical trial experience with Klonopin in seizure disorder patients 65 years of age and older. In general, elderly patients should be started on low doses of Klonopin and observed closely (see PRECAUTIONS: Geriatric Use). Panic Disorder Adults The initial dose for adults with panic disorder is 0.25 mg bid. An increase to the target dose for most patients of 1 mg/day may be made after 3 days. The recommended dose of 1 mg/day is based on the results from a fixed dose study in which the optimal effect was seen at 1 mg/day. Higher doses of 2, 3 and 4 mg/day in that study were less effective than the 1 mg/day dose and were associated with more adverse effects. Nevertheless, it is possible that some individual patients may benefit from doses of up to a maximum dose of 4 mg/day, and in those instances, the dose may be increased in increments of 0.125 to 0.25 mg bid every 3 days until panic disorder is controlled or until side effects make further increases undesired. To reduce the inconvenience of somnolence, administration of one dose at bedtime may be desirable. Treatment should be discontinued gradually, with a decrease of 0.125 mg bid every 3 days, until the drug is completely withdrawn. There is no body of evidence available to answer the question of how long the patient treated with clonazepam should remain on it. Therefore, the physician who elects to use Klonopin for extended periods should periodically reevaluate the long-term usefulness of the drug for the individual patient. Pediatric Patients There is no clinical trial experience with Klonopin in panic disorder patients under 18 years of age. Geriatric Patients There is no clinical trial experience with Klonopin in panic disorder patients 65 years of age and older. In general, elderly patients should be started on low doses of Klonopin and observed closely (see PRECAUTIONS: Geriatric Use).
Pregnancy and lactation
Nursing Mothers The effects of Klonopin on the breastfed infant and on milk production are unknown. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for Klonopin and any potential adverse effects on the breastfed infant from Klonopin or from the underlying maternal condition.

Interactions

Drug Interactions Effect of Concomitant Use of Benzodiazepines and Opioids The concomitant use of benzodiazepines and opioids increases the risk of respiratory depression because of actions at different receptor sites in the CNS that control respiration. Benzodiazepines interact at GABAA sites, and opioids interact primarily at mu receptors. When benzodiazepines and opioids are combined, the potential for benzodiazepines to significantly worsen opioid-related respiratory depression exists. Limit dosage and duration of concomitant use of benzodiazepines and opioids, and follow patients closely for respiratory depression and sedation. Effect of Clonazepam on the Pharmacokinetics of Other Drugs Clonazepam does not appear to alter the pharmacokinetics of phenytoin, carbamazepine or phenobarbital. Clonazepam has the potential to influence concentrations of phenytoin. Monitoring of phenytoin concentration is recommended when clonazepam is co-administrated with phenytoin. The effect of clonazepam on the metabolism of other drugs has not been investigated. Effect of Other Drugs on the Pharmacokinetics of Clonazepam Literature reports suggest that ranitidine, an agent that decreases stomach acidity, does not greatly alter clonazepam pharmacokinetics. In a study in which the 2 mg clonazepam orally disintegrating tablet was administered with and without propantheline (an anticholinergic agent with multiple effects on the GI tract) to healthy volunteers, the AUC of clonazepam was 10% lower and the Cmax of clonazepam was 20% lower when the orally disintegrating tablet was given with propantheline compared to when it was given alone. The selective serotonin reuptake inhibitors sertraline (weak CYP3A4 inducer) and fluoxetine (CYP2D6 inhibitor), and the anti-epileptic drug felbamate (CYP2C19 inhibitor and CYP3A4 inducer) do not affect the pharmacokinetics of clonazepam. Cytochrome P-450 inducers, such as phenytoin, carbamazepine, lamotrigine, and phenobarbital induce clonazepam metabolism, causing an approximately 38% decrease in plasma clonazepam levels. Although clinical studies have not been performed, based on the involvement of the cytochrome P-450 3A family in clonazepam metabolism, inhibitors of this enzyme system, notably oral antifungal agents (e.g., fluconazole), should be used cautiously in patients receiving clonazepam because they may impair the metabolism of clonazepam leading to exaggerated concentrations and effects. Pharmacodynamic Interactions The CNS-depressant action of the benzodiazepine class of drugs may be potentiated by alcohol, narcotics, barbiturates, nonbarbiturate hypnotics, antianxiety agents, the phenothiazines, thioxanthene and butyrophenone classes of antipsychotic agents, monoamine oxidase inhibitors and the tricyclic antidepressants, and by other anticonvulsant drugs.

More information

Category Value
Authorisation number NDA017533
Agency product number 5PE9FDE8GB
Orphan designation No
Product NDC 0004-0058,0004-0068,0004-0098
Date Last Revised 07-12-2018
Type HUMAN PRESCRIPTION DRUG
RXCUI 206159
Storage and handling Store at 25°C (77°F); excursions permitted to 15° to 30°C (59° to 86°F).
Marketing authorisation holder Genentech, Inc.
Warnings WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death (see WARNINGS and PRECAUTIONS). Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required. Follow patients for signs and symptoms of respiratory depression and sedation.