Componentes:
Opção de tratamento:
Medicamente revisado por Kovalenko Svetlana Olegovna, Farmácia Última atualização em 23.03.2022
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20 principais medicamentos com os mesmos componentes:
20 principais medicamentos com os mesmos tratamentos:
A dosagem de Риталмекс (cloridrato de mexiletina, USP) deve ser individualizada com base na resposta e tolerância, ambas relacionadas à dose. Recomenda-se a administração com alimentos ou antiácidos. Inicie a terapia com Риталмекс (mexiletina hcl) com 200 mg a cada oito horas quando o controle rápido da arritmia não for essencial. Recomenda-se um mínimo de dois a três dias entre os ajustes de dose. A dose pode ser ajustada em incrementos de 50 ou 100 mg para cima ou para baixo.
Como em qualquer medicamento antiarrítmico, são necessárias avaliações clínicas e eletrocardiográficas (incluindo monitoramento de Holter, se necessário para avaliação) para determinar se o efeito antiarrítmico desejado foi obtido e para orientar a titulação e o ajuste da dose.
O controle satisfatório pode ser alcançado na maioria dos pacientes em 200 a 300 mg, administrados a cada oito horas com alimentos ou antiácidos. Se uma resposta satisfatória não tiver sido alcançada em 300 mg q8h, e o paciente tolerar bem Риталмекс (mexiletina hcl), uma dose de 400 mg q8h pode ser tentada. À medida que a gravidade dos efeitos colaterais do SNC aumenta com a dose diária total, a dose não deve exceder 1200 mg / dia.
Em geral, pacientes com insuficiência renal exigirão as doses usuais de Риталмекс (mexiletina hcl). Pacientes com doença hepática grave, no entanto, podem exigir doses mais baixas e devem ser monitorados de perto. Da mesma forma, a insuficiência cardíaca congestiva do lado direito pode reduzir o metabolismo hepático e reduzir a dose necessária. O nível plasmático também pode ser afetado por certos medicamentos concomitantes (ver PRECAUÇÕES: INTERAÇÕES DE DROGAS).
Dose de carregamento
Quando o controle rápido da arritmia ventricular é essencial, uma dose inicial de carga de 400 mg de Риталмекс (mexiletina hcl) pode ser administrada, seguida por uma dose de 200 mg em oito horas. O início do efeito terapêutico é geralmente observado dentro de 30 minutos a duas horas.
Cronograma de dosagem Q12H
Alguns pacientes que respondem a Риталмекс (mexiletina hcl) podem ser transferidos para um esquema posológico de 12 horas para melhorar a conveniência e a conformidade. Se for alcançada uma supressão adequada em uma dose de Риталмекс (mexiletina hcl) de 300 mg ou menos a cada oito horas, a mesma dose diária total pode ser administrada em doses divididas a cada 12 horas, monitorando cuidadosamente o grau de supressão da ectopia ventricular. Esta dose pode ser ajustada até um máximo de 450 mg a cada 12 horas para obter a resposta desejada.
Transferindo para Риталмекс (mexiletine hcl)
O seguinte esquema de dosagem, com base em considerações teóricas e não em dados experimentais, é sugerido para a transferência de pacientes de outros agentes antiarrítmicos orais da Classe I para Риталмекс (mexiletina hcl) : Риталмекс (mexiletina hcl) o tratamento pode ser iniciado com uma dose de 200 mg, e titulado para resposta, conforme descrito acima, 6-12 horas após a última dose de sulfato de quinidina, 3-6 horas após a última dose de procainamida, 6-12 horas após a última dose de disopiramida ou 8-12 horas após a última dose de tocainida.
Nos pacientes em que é provável que a retirada do agente antiarrítmico anterior produza arritmias com risco de vida, recomenda-se a hospitalização do paciente.
Ao transferir da lidocaína para Риталмекс (mexiletina hcl), a infusão de lidocaína deve ser interrompida quando a primeira dose oral de Риталмекс (mexiletina hcl) for administrada. A linha de infusão deve ser deixada aberta até que a supressão da arritmia pareça ser mantida satisfatoriamente.
Deve-se considerar a semelhança dos efeitos adversos da lidocaína e Риталмекс (mexiletina hcl) e a possibilidade de serem aditivos.
WARNINGS
Mortality: In the National Heart, Lung and Blood Institute's Cardiac Arrhythmia Suppression Trial (CAST), a long-term, multicentered, randomized, double-blind study in patients with asymptomatic non-life-threatening ventricular arrhythmias who had a myocardial infarction more than six days but less than two years previously, an excessive mortality or non-fatal cardiac arrest rate (7.7%) was seen in patients treated with encainide or flecainide compared with that seen in patients assigned to carefully matched placebo-treated groups (3.0%). The average duration of treatment with encainide or flecainide in this study was ten months.
The applicability of the CAST results to other populations (e.g., those without recent myocardial infarction) is uncertain. Considering the known proarrhythmic properties of Риталмекс (mexiletine hcl) and the lack of evidence of improved survival for any antiarrhythmic drug in patients without life-threatening arrhythmias, the use of Риталмекс (mexiletine hcl) as well as other antiarrhythmic agents should be reserved for patients with life-threatening ventricular arrhythmia.
Acute Liver Injury
In post-marketing experience abnormal liver function tests have been reported, some in the first few weeks of therapy with Риталмекс (mexiletine hydrochloride, USP). Most of these have been observed in the setting of congestive heart failure or ischemia and their relationship to Риталмекс (mexiletine hcl) has not been established.
PRECAUTIONS
General
If a ventricular pacemaker is operative, patients with second or third degree heart block may be treated with Риталмекс (mexiletine hydrochloride, USP) if continuously monitored. A limited number of patients (45 of 475 in controlled clinical trials) with pre-existing first degree AV block were treated with Риталмекс (mexiletine hcl) ; none of these patients developed second or third degree AV block. Caution should be exercised when it is used in such patients or in patients with pre-existing sinus node dysfunction or intraventricular conduction abnormalities.
Like other antiarrhythmics Риталмекс (mexiletine hydrochloride, USP) can cause worsening of arrhythmias. This has been uncommon in patients with less serious arrhythmias (frequent premature beats or non-sustained ventricular tachycardia: see ADVERSE REACTIONS), but is of greater concern in patients with life-threatening arrhythmias such as sustained ventricular tachycardia. In patients with such arrhythmias subjected to programmed electrical stimulation or to exercise provocation, 10-15% of patients had exacerbation of the arrhythmia, a rate not greater than that of other agents.
Риталмекс (mexiletine hcl) should be used with caution in patients with hypotension and severe congestive heart failure because of the potential for aggravating these conditions.
Since Риталмекс (mexiletine hcl) is metabolized in the liver, and hepatic impairment has been reported to prolong the elimination half-life of Риталмекс (mexiletine hcl) , patients with liver disease should be followed carefully while receiving Риталмекс (mexiletine hcl). The same caution should be observed in patients with hepatic dysfunction secondary to congestive heart failure.
Concurrent drug therapy or dietary regimens which may markedly alter urinary pH should be avoided during Риталмекс (mexiletine hcl) therapy. The minor fluctuations in urinary pH associated with normal diet do not affect the excretion of Риталмекс (mexiletine hcl).
SGOT Elevation and Liver Injury
In three-month controlled trials, elevations of SGOT greater than three times the upper limit of normal occurred in about 1% of both mexiletine-treated and control patients. Approximately 2% of patients in the mexiletine compassionate use program had elevations of SGOT greater than or equal to three times the upper limit of normal. These elevations frequently occurred in association with identifiable clinical events and therapeutic measures such as congestive heart failure, acute myocardial infarction, blood transfusions and other medications. These elevations were often asymptomatic and transient, usually not associated with elevated bilirubin levels and usually did not require discontinuation of therapy. Marked elevations of SGOT ( > 1000 U/L) were seen before death in four patients with end-stage cardiac disease (severe congestive heart failure, cardiogenic shock).
Rare instances of severe liver injury, including hepatic necrosis, have been reported in association with Риталмекс (mexiletine hcl) treatment. It is recommended that patients in whom an abnormal liver test has occurred, or who have signs or symptoms suggesting liver dysfunction, be carefully evaluated. If persistent or worsening elevation of hepatic enzymes is detected, consideration should be given to discontinuing therapy.
Blood Dyscrasias
Among 10,867 patients treated with mexiletine in the compassionate use program, marked leukopenia (neutrophils less than 1000/mm3) or agranulocytosis were seen in 0.06% and milder depressions of leukocytes were seen in 0.08%, and thrombocytopenia was observed in 0.16%. Many of these patients were seriously ill and receiving concomitant medications with known hematologic adverse effects. Rechallenge with mexiletine in several cases was negative. Marked leukopenia or agranulocytosis did not occur in any patient receiving Риталмекс (mexiletine hcl) alone; five of the six cases of agranulocytosis were associated with procainamide (sustained release preparations in four) and one with vinblastine. If significant hematologic changes are observed, the patient should be carefully evaluated, and, if warranted, Риталмекс (mexiletine hcl) should be discontinued. Blood counts usually return to normal within one month of discontinuation. (See ADVERSE REACTIONS).
Convulsions (seizures) did not occur in Риталмекс (mexiletine hcl) controlled clinical trials. In the compassionate use program, convulsions were reported in about 2 of 1000 patients. Twenty-eight percent of these patients discontinued therapy. Convulsions were reported in patients with and without a prior history of seizures. Mexiletine should be used with caution in patients with known seizure disorder.
Carcinogenesis, Mutagenesis and Impairment of Fertility
Studies of carcinogenesis in rats (24 months) and mice (18 months) did not demonstrate any tumorigenic potential. Риталмекс (mexiletine hcl) was found to be non-mutagenic in the Ames test. Риталмекс (mexiletine hcl) did not impair fertility in the rat.
Pregnancy
Teratogenic Effects
Pregnancy Category C
Reproduction studies performed with Риталмекс (mexiletine hydrochloride, USP) in rats, mice and rabbits at doses up to four times the maximum human oral dose (24 mg/kg in a 50 kg patient) revealed no evidence of teratogenicity or impaired fertility but did show an increase in fetal resorption. There are no adequate and well-controlled studies in pregnant women; this drug should be used in pregnancy only if the potential benefit justifies the potential risk to the fetus.
Nursing Mothers
Риталмекс (mexiletine hcl) appears in human milk in concentrations similar to those observed in plasma. Therefore, if the use of Риталмекс (mexiletine hcl) is deemed essential, an alternative method of infant feeding should be considered.
Pediatric Use
Safety and effectiveness in the pediatric population have not been established.
However, we will provide data for each active ingredient