- mianserin hydrochloride BP
C18H20N2,HC1 300.8 CAS No. 21535-47-7
Mianserin hydrochloride is known chemically as: 1, 2, 3, 4, 10, 14b-hexahydro-2-methyldibenzo [c,f] pyrazino [1,2-a] azepine monohydrochloride. It is an odourless, creamy white, crystalline powder that is soluble in water, ethanol, methanol and chloroform. It belongs to the tetracyclic series of antidepressant compounds, the piperazinoazepines. These are chemically different from the common tricyclic antidepressants. MW: 300.8. The empirical formula is C18H20N2HCl.
: mianserin hydrochloride
: Tolvon tablets contain potato starch, silica colloidal anhydrous, magnesium stearate, methyl cellulose, calcium hydrogen phosphate, hypromellose, macrogol 8000 and titanium dioxide (171).
Mianserin, the active component of Tolvon, belongs to the piperazino-azepine group of compounds which are chemically not related to the tricyclic antidepressants (TCAs). Its structure lacks the basic side-chain which is considered to be responsible for the anticholinergic activity of the TCAs. Tolvon increases central noradrenergic neurotransmission by alpha2-autoreceptor blockade and noradrenaline-reuptake inhibition. In addition, interactions with serotonin receptors in the central nervous system have been found. Human pharmaco-EEG studies have confirmed the antidepressant profile of Tolvon. The antidepressant efficacy of Tolvon has been demonstrated in placebo-controlled trials and has been shown to be similar to other currently used antidepressants. Moreover, it possesses anxiolytic and sleep improving properties which are of value in treating patients with anxiety or sleep disturbances associated with depressive illness. The histamine H1 and alpha1- antagonistic activity of Tolvon is thought to be responsible for its sedative properties. Tolvon is well tolerated, also by the elderly and by patients with cardiovascular disease. At therapeutically effective doses Tolvon has virtually no anticholinergic activity and has practically no effect on the cardiovascular system. As compared to the TCAs, it causes less cardiotoxic effects on overdose. Tolvon does not antagonise the action of sympathicomimetic agents and antihypertensive drugs which interact with adrenergic receptors (eg. bethanidine) or alpha2 receptors (eg. clonidine, methyldopa).
After oral administration of Tolvon the active constituent, mianserin, is rapidly and well absorbed, reaching peak plasma levels within 3 hours. The bioavailability is approx. 20%. Binding of mianserin to plasma proteins is approx. 95%. The half-life of elimination (21-61 hours) is sufficient to justify once-a-day dosing. Steady-state plasma levels are reached within 6 days. Mianserin is extensively metabolised and eliminated via the urine and faeces within 7-9 days. Major pathways of biotransformation are demethylation and oxidation, followed by conjugation.
For the treatment of major depression.
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Hypersensitivity to mianserin or any of the excipients listed under Description
Mania
Severe liver disease
Concomitant use of mianserin with monoamine oxidase (MAO) inhibitors (see Interactions with other drugs)
The risk of suicidality (suicidal ideation and suicidal behaviours) is inherent in depression and may persist until significant remission occurs. This risk must be considered in all depressed patients. Patients with depression may experience worsening of their depressive symptoms and/or the emergence of suicidal ideation and/or behaviours whether or not they are taking antidepressant medication, and this risk may persist until significant remission occurs. Suicide is a known risk in depression and certain other psychiatric disorders, and these disorders themselves are the strongest predictors of suicide. As improvement may not occur during the first few weeks or more of treatment, patients should be closely monitored for clinical worsening and suicidality, especially at the beginning of a course of treatment, or at the time of dose changes, either increases or decreases. Consideration should be given to changing the therapeutic regimen, including possibly discontinuing the medication, in patients whose depression is persistently worse or whose emergent suicidality is severe, abrupt in onset, or was not part of the patient's presenting symptoms. Patients (and caregivers of patients) should be alerted about the need to monitor for any worsening of their condition and/or the emergence of suicidal ideation or behaviour or thoughts of harming themselves and to seek medical advice immediately if these symptoms present. Patients with co-morbid depression associated with other psychiatric disorders being treated with antidepressants should be similarly observed for clinical worsening and suicidality. Pooled analysis of short-term placebo-controlled trials of antidepressant drugs (SSRIs and others) showed that these drugs increased the risk of suicidal ideation and/or behaviours in children, adolescents, and young adults (aged 18-24 years) with major depressive disorder (MDD) and other psychiatric disorders during the initial treatment (generally the first one to two months). Short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond the age of 24 years; there was a reduction with antidepressants compared to placebo in adults aged 65 years and older. The pooled analyses of placebo-controlled trials in children and adolescents with MDD, obsessive compulsive disorder (OCD), or other psychiatric disorders included a total of 24 short-term trials (4 to 16 weeks) of 9 antidepressant drugs in over 4,400 patients. The pooled analyses of placebo- controlled trials in adults with MDD or other psychiatric disorders included a total of 295 short-term trials (median duration of 2 months) of 11 antidepressant drugs in over 77,000 patients. There was considerable variation in the risk of suicidality among drugs, but a tendency towards an increase in the younger patients for almost all drugs studied. There were differences in absolute risk of suicidality across different indications, with the highest incidence in MDD trials. The risk differences (drug vs placebo), however, were relatively stable within age strata and across indications. No suicides occurred in any of the paediatric trials. There were few suicides in the adult trials, but the number was not sufficient to reach any conclusion about the effect of antidepressants on suicide. It is unknown whether suicidality risk extends to longer-term use, i.e. beyond several months. However, there is substantial evidence from placebo-controlled maintenance trials in adults with depression that the use of antidepressants can delay the recurrence of depression. Symptoms of anxiety, agitation, panic attacks, insomnia, irritability, hostility, (aggressiveness), impulsivity, akathisia (psychomotor restlessness), hypomania, and mania, have been reported in adults, adolescents and children being treated with antidepressants for major depressive disorder as well as for other indications, both psychiatric and non-psychiatric. Although a causal link between the emergence of such symptoms and either worsening of depression and/or emergence of suicidality has not been established, there is concern that such symptoms may be precursors of emerging suicidality. Families and caregivers of children and adolescents being treated with antidepressants for MDD or for any other condition (psychiatric or non-psychiatric) should be informed about the need to monitor these patients for the emergence of agitation, irritability, unusual changes in behaviour, and other symptoms described above, as well as the emergence of suicidality and to report such symptoms immediately to health care providers. It is particularly important that monitoring be undertaken during the initial few months of antidepressant treatment or at times of dose increase or decrease. Prescriptions for Tolvon should be written for the smallest quantity of tablets consistent with good patient management, in order to reduce the risk of overdose.
The safety and efficacy of Tolvon for the treatment of depression or other psychiatric disorders in children and adolescents aged less than 18 years has not been satisfactorily established. Tolvon should not be used in this age group for the treatment of depression or other psychiatric disorders (See also PRECAUTIONS - Clinical Worsening and Suicide Risk).
A major depressive episode may be the initial presentation of bipolar disorder. It is generally believed that treating such an episode with an antidepressant alone can increase the likelihood of precipitation of a mixed/manic episode in patients at risk of bipolar disorder. Prior to initiating treatment with an antidepressant, patients should be adequately screened to determine if they are at risk for bipolar disorder; such screening should include a detailed psychiatric history, including a family history of suicide, bipolar disorder and depression. When the depressive phase of bipolar is being treated, it can transform into the manic phase. Patients should be closely monitored and TOLVON discontinued in any patient with signs or symptoms of a mixed/manic episode.
Neutropenia, agranulocytosis and thrombocytopenia have been reported during treatment with Tolvon. These reactions have occurred most commonly after 4 to 6 weeks of treatment. A full blood count should be performed in patients complaining of sore throat, stomatitis, fever, malaise, flu-like symptoms or other signs of infection. Treatment with Tolvon should be discontinued if neutropenia is observed in the full blood count. Elderly patients who have a white blood cell disorder should have a full blood count performed every 4 weeks during the first 3 months of treatment.
Although Tolvon at therapeutic doses has not been shown to have cardiotoxic effects, caution should be exercised in treating patients with cardiac impairment (e.g. heart-block, recent myocardial infarction, unstable heart disease) who should be monitored carefully. QT prolongation and ventricular arrhythmias (including Torsades de Pointes) have been reported during the post-marketing use of Tolvon (see ADVERSE EFFECTS). Tolvon should be used with caution in patients with risk factors for QT prolongation/TdP including congenital long QT syndrome, age >65 years, female sex, structural heart disease/left ventricular (LV) dysfunction, renal or hepatic disease, use of medicines that inhibit the metabolism of Tolvon, and the concomitant use of other QTc prolonging medicines (see INTERACTIONS WITH OTHER DRUGS). Hypokalaemia and hypomagnesaemia should be corrected prior to treatment. Consideration should be given to stop Tolvon treatment or reducing the dose if the QTc interval is >500ms or increases by >60ms.
Tolvon, especially in the first days of treatment, may impair concentration and psychomotor skills and hence ability to drive or engage in any activity requiring alertness may be impaired. This risk is increased if alcohol is taken concomitantly with Tolvon.
Patients with narrow angle glaucoma should be monitored even though anticholinergic side effects are not expected with Tolvon therapy.
As clinical experience is lacking in patients suffering from epilepsy, care must be exercised. Tolvon may lower the convulsive threshold in such patients. It may therefore be necessary to adjust the dose of anticonvulsants if administered. Convulsions have also been reported in nonepileptic patients. If convulsions occur, Tolvon therapy should be discontinued. However, mianserin products including Tolvon should be avoided, if possible, in patients with epilepsy.
Patients with symptoms suggestive of prostatic hypertrophy should be monitored even though anticholinergic side effects are not expected with Tolvon.
Depressed patients suffering from liver or renal insufficiency should be carefully monitored, because of the possibility of increases in serum-derived liver enzyme levels (mainly ALT) and impaired metabolism or excretion. If jaundice occurs, Tolvon should be discontinued.
Tolvon, like other antidepressants, may precipitate hypomania in susceptible subjects with bipolar depressive illness. In such a case treatment with Tolvon should be withdrawn. The possibility of the depressed patient attempting suicide should be borne in mind and large amounts of the drug should not be held by the patient.
Slight alterations of the glucose tolerance curve and insulin levels have been observed in some patients with diabetes mellitus, who were treated with Tolvon. Therefore, in such patients regular monitoring of blood glucose levels is advisable.
Clinicians should inform anaesthetists if surgery becomes necessary during Tolvon treatment.
Use in pregnancy (Category B2)
There is limited experience of the effects of Tolvon in human pregnancy and therefore it should not be given to pregnant women or those likely to become pregnant unless the expected benefit outweighs the potential risk. Available data on the few studies conducted in animals show no evidence of an increase of occurrence of foetal damage, however, the number of implantation sites were significantly reduced in a rat fertility study in which dams were dosed at greater than 3mg/kg/day. There is only limited evidence of safety in pregnancy.
Use in lactation
It is not known whether mianserin hydrochloride is excreted in human milk nor whether it has a harmful effect on newborns. Therefore, it is recommended that Tolvon not be given to nursing mothers.
Effects on ability to drive and use machines
Tolvon may impair psychomotor performance for the first few days of treatment. In general, depressed patients treated with antidepressants should avoid the performance of potentially dangerous tasks such as driving a motor vehicle or operating machinery.
Concomitant use of barbiturates with Tolvon is not recommended as there may be additive central depressant effects. Tolvon should not be administered concomitantly with MAOIs (such as moclobemide, tranylcypromine and linezolid) or within 2 weeks after MAOIs have been discontinued. In the opposite way about two weeks should pass before patients treated with mianserin should be treated with MAO inhibitors. Tolvon may affect the metabolism of coumarin derivatives such as warfarin. Patients receiving warfarin therapy should receive coagulation monitoring when Tolvon is initiated or stopped. It has been shown that alcohol potentiates the impairment of psychomotor skills especially in the initial period of treatment. Patients should be advised to avoid taking alcohol during treatment. Although there is evidence that the tyramine uptake into peripheral noradrenergic neurones in depressed patients receiving Tolvon is not inhibited, it is nevertheless advisable to check the blood pressure regularly in those patients who are concomitantly treated with antihypertensives. Tolvon has been used with benzodiazepines without apparent ill effect. Concomitant treatment with antiepileptic drugs that are CYP 3A4 inducers (like phenytoin and carbamazapine) can result in reduced plasma levels of mianserin. Dose adjustment should be considered when concomitant treatment with these drugs is initiated or discontinued. Phenytoin levels need to be monitored. The risk of QTc prolongation and/or ventricular arrhythmias (e.g. Torsades de Pointes) is increased with concomitant use of other medicines which prolong the QTc interval (e.g. some anti-psychotics and antibiotics). Please check the product information of other medicines administered for information on their effects on the QTc interval.
Reporting frequencies are described as follows, according to CIOMS Working Group III: Very common:> 10%; common:1 to 10%; uncommon 0.1 to 1%; rare:0.01 to 0.1%; very rare:< 0.01%; frequency not known.
Blood and the lymphatic system disorders. Very rare:
blood dyscrasias.
Investigations. Uncommon:
weight gain.
General disorders. Rare:
oedema.
Musculoskeletal and connective tissue disorders. Rare:
arthralgia/arthritis.
Skin and subcutaneous tissue disorders. Rare:
exanthema.
Nervous system disorders. Common:
sedation (primarily at initiation of treatment). Very rare:convulsions, hyperkinesia (restless legs), neuroleptic malignant syndrome.
Psychiatric disorders. Rare:
hypomania.
Vascular disorders. Rare:
hypotension (postural).
Cardiac disorders. Very rare:bradycardia. Frequency not known:Electrocardiogram QT prolonged, Torsade de Pointes.
Hepato-biliary disorders. Rare:.
disturbances of liver function including jaundice, hepatitis
Frequency not known:
elevated liver enzymes, hepatic function abnormal
Serious or life-threatening reactions.
Blood and the lymphatic system disorders. Very rare
: bone marrow depression resulting in neutropenia, granulocytopenia, leukopenia, agranulocytosis, pancytopenia, thrombocytopenia, anaemia (aplastic, B12 deficiency, haemolytic, hypoplastic, normocytic, sideroblastic).
Cardiac disorders. Very rare:
cardiac arrest, cardiac failure.
These reactions necessitate immediate withdrawal of Tolvon therapy and are reversible on stopping treatment. If jaundice, hypomania or convulsions occur at therapeutic dosages, then treatment should be withdrawn.
Other reactions.
The following adverse events have been reported in association with Tolvon use. A causal relationship has not been established.
Gastrointestinal disorders. Very common:
dry mouth, constipation.
Nervous system disorders. Common:tremor, headache. Rare/ very rare:parasthesia. Respiratory, thoracic and mediastinal disorders. Rare/ very rare:nasal congestion. Eye disorders. Rare/ very rare:vision abnormality, diplopia.
Reproductive system and breast disorders. Rare/ very rare:
gynaecomastia, impotence.
Muscoloskeletal and connective tissue disorders. Rare/ very rare:
myalgia.
Skin and subcutaneous tissue disorders. Rare/ very rare:
pruritus.
Vascular disorders. Rare/ very rare:
hypertension.
Cardiac disorders. Rare/ very rare:
tachycardia.
Ear and labyrinth disorders. Rare/ very rare:
tinnitus.
Psychiatric disorders. Rare/ very rare:
confusion, agitation.
Cases of suicidal ideation and suicidal behaviours have been reported during mianserin therapy or early after treatment discontinuation (see PRECAUTIONS).
More common reactions
| More Common Reactions (from clinical trials) | ||
| Reaction | % in first week * | % on maintenance therapy * |
| Tiredness, lethargy and drowsiness Dry mouth Dizziness, faintness, weakness, vertigo Drug related withdrawal in clinical trials Tremor Headache | 34% 33% > 5% - - - | 5 - 10% 10 - 20% 5% 8% * * 5% * * 6% * * |
* Percentages are estimates from clinical trials; not corrected for baseline incidence.
* * These figures represent overall incidence.
Note: Anticholinergic type side effects are less frequent than with the tricyclic antidepressants and may be difficult to distinguish from symptoms of depression.
Tolvon tablets should be taken orally between meals, preferably with a little fluid, and swallowed without chewing.
Tolvon should not be used in children and adolescents under the age of 18 years (see Precautions).
The initial dosage of Tolvon should be judged individually. It is recommended that treatment begin with a daily dose of 30mg given in three divided doses or a single bed time dose and be adjusted weekly in the light of the clinical response. The effective daily dose for adult patients usually lies between 30mg and 90mg (average 60mg) in divided doses or as a single bedtime dose. A maximum daily dose of 120mg should not be exceeded. It is often advantageous to maintain antidepressant treatment for several months after initial clinical improvement has occurred.
Initially, not more than 30mg daily and increased slowly under close supervision. A reduced dose may also be required for maintenance as hepatic, renal or cardiovascular function may be impaired. Pharmacokinetic studies of mianserin in the elderly patient suggest a longer half life and slower metabolic clearance. This implies that a single night time dose of mianserin should be preferred to divided doses in the elderly patient.
The toxic effects of Tolvon are different from those of the tricyclics and there is no specific antidote.
Symptoms of acute overdose are generally confined to prolonged sedation. Cardiac arrhythmias, convulsions, severe hypotension and respiratory depression occur rarely. Electrocardiogram QTc prolonged and Torsade de Pointes has also been reported. ECG monitoring should be undertaken. There is no specific antidote.
Treatment is by gastric lavage with appropriate symptomatic and supportive therapy for vital functions.
10 mg Tablets: white, film coated, round, biconvex, 6 mm diameter, coded "CT" over "4" on one side and "Organon" and a star on the reverse. 20 mg Tablets: white, film coated, round, biconvex, 7mm diameter, coded "CT" over "6" on one side and "Organon" and a star on the reverse.
10 mg Tablets: 3 years below 300C 20 mg Tablets: 3 years below 300C Protect from light. Tolvon 20 mg tablets AUST R 65541 Tolvon 10 mg tablets AUST R 65543
Merck Sharp & Dohme (Australia) Pty Limited 54-68 Ferndell Street South Granville NSW 2142 Australia
Prescription only medicine (S4)
Date of first inclusion in the ARTG: 02 September 1998
Date of most recent TGA approval: 4 January 2007 Date of most recent amendment: 19 August 2013