No

Antiarrhythmic Agent, Class I-B

Suppress and prevent symptomatic life-threatening ventricular arrhythmias

C

Hypersensitivity to tocainide, any component, or to any local anesthetics of the amide type; second- or third-degree heart block (except in patients with a functioning artificial pacemaker)

Watch for proarrhythmic effects. Correct electrolyte imbalances before initiating (especially hypokalemia and hyperkalemia). Use cautiously in heart failure. Adjust dose in patients with significant renal or hepatic impairment. Bone marrow depression can rarely occur during the first 3 months of therapy.

>10%:

Central nervous system: Dizziness (8% to 15%)

Gastrointestinal: Nausea (14% to 15%)

1% to 10%:

Cardiovascular: Tachycardia (3%), bradycardia/angina/palpitations (0.5% to 1.8%), hypotension (3%)

Central nervous system: Nervousness (0.5% to 1.5%), confusion (2% to 3%), headache (4.6%), anxiety, incoordination, giddiness, vertigo

Dermatologic: Rash (0.5% to 8.4%)

Gastrointestinal: Vomiting (4.5%), diarrhea (4% to 5%), anorexia (1% to 2%), loss of taste

Neuromuscular & skeletal: Paresthesia (3.5% to 9%), tremor (dose-related: 2.9% to 8.4%), ataxia (dose-related: 2.9% to 8.4%), hot and cold sensations

Ocular: Blurred vision (~1.5%), nystagmus (1%)

<1% (Limited to important or life-threatening symptoms): Hypersensitivity reactions, increased ANA, sinoatrial block, syncope, vasovagal episodes, diaphoresis, edema, fever, chills, cinchonism, asthenia, malaise, AV block, hypertension, increased QRS duration, prolonged QT interval, right bundle branch block, cardiomegaly, angina, pulmonary embolism, sinus arrest, vasculitis, orthostatic hypotension, pericarditis, hepatitis, jaundice, abnormal liver function tests, pancreatitis, abdominal pain, constipation, dysphagia, dyspepsia, stomatitis, xerostomia, muscle cramps, neck pain, depression, psychosis, psychic disturbances, agitation, decreased mental acuity, dysarthria, impaired memory, slurred speech, sleep disturbance, insomnia, local anesthesia, myasthenia gravis, convulsions, coma, pneumonia, interstitial pneumonitis, fibrosing alveolitis, pulmonary fibrosis, dyspnea, hiccup, yawning, pulmonary edema, respiratory arrest, urticaria, alopecia, pallor, pruritus, erythema multiforme, exfoliative dermatitis, Stevens-Johnson syndrome, diplopia, earache, taste perversion, urinary retention, polyuria, hallucinations, delirium

Case reports: Pericarditis, immune complex glomerulonephritis, granulomatous hepatitis

Note: Rare, potentially severe hematologic reactions, have occurred (generally within the first 12 weeks of therapy). These may include agranulocytosis, bone marrow depression, aplastic anemia, hypoplastic anemia, hemolytic anemia, anemia, leukopenia, neutropenia, thrombocytopenia, and eosinophilia.

Has a narrow therapeutic index and severe toxicity may occur slightly above the therapeutic range, especially with other antiarrhythmic drugs; and acute ingestion of twice the daily therapeutic dose is potentially life-threatening; symptoms of overdose include sedation, confusion, coma, seizures, respiratory arrest and cardiac toxicity (sinus arrest, A-V block, asystole, and hypotension); the QRS and Q-T intervals are usually normal, although they may be prolonged after massive overdose; other effects include dizziness, paresthesias, tremor, ataxia, and GI disturbance.

Treatment is supportive, using conventional therapies (fluids, positioning, vasopressors, antiarrhythmics, anticonvulsants); sodium bicarbonate may reverse the QRS prolongation (if present), bradyarrhythmias, and hypotension; enhanced elimination with dialysis, hemoperfusion or repeat charcoal is not effective.

Rifampin may reduce tocainide blood levels.

Urinary alkalinizers (antacids, sodium bicarbonate, acetazolamide) may increase tocainide blood levels.

Class 1B antiarrhythmic agent; suppresses automaticity of conduction tissue, by increasing electrical stimulation threshold of ventricle, HIS-Purkinje system, and spontaneous depolarization of the ventricles during diastole by a direct action on the tissues; blocks both the initiation and conduction of nerve impulses by decreasing the neuronal membrane's permeability to sodium ions, which results in inhibition of depolarization with resultant blockade of conduction

Absorption: Oral: Extensive, 99% to 100%

Distribution: V_d: 1.62-3.2 L/kg

Protein binding: 10% to 20%

Metabolism: In the liver to inactive metabolites; first-pass effect is negligible

Half-life: 11-14 hours, prolonged with renal and hepatic impairment with half-life increased to 23-27 hours

Time to peak: Peak serum levels occur within 30-160 minutes

Elimination: In urine (40% to 50% as unchanged drug)

Adults: Oral: 1200-1800 mg/day in 3 divided doses, up to 2400 mg/day

Hemodialysis: Moderately dialyzable (20% to 50%)

Dosing adjustment in hepatic impairment: Maximum daily dose: 1200 mg

Should be administered with food

Therapeutic: 5-12 mg/mL (SI: 22-52 mmol/L)

The prophylactic use of tocainide in patients after myocardial infarction confers no benefit and in fact may be harmful. Great care is needed in administration of tocainide in the elderly and in patients with heart failure, shock, or hepatic disease, as toxic effects of tocainide may become evident earlier in these patients. This is especially problematic since tocainide-induced seizures may induce extension of underlying myocardial infarction. It is important to recognize that tocainide has a narrow therapeutic index. Severe toxicity may occur at doses slightly above the therapeutic range, particularly when tocainide is administered together with other antiarrhythmic drugs. While tocainide toxicity may elicit seizures, tocainide may also cause respiratory arrest and cardiac toxicity (AV block, asystole, and hypotension).

Dizziness is common; may cause nervousness or confusion

May cause agranulocytosis; use caution with clozapine and carbamazepine; barbiturates may decrease the serum levels of tocainide

No information available to require special precautions

No effects or complications reported

Take exactly as directed, with food. If dose is missed, take as soon as possible, do not double next dose. Do not discontinue without consulting prescriber. You will need regular cardiac checkups while taking this medication. You may experience dizziness, nervousness, or visual changes (use caution when driving or engaging in tasks requiring alertness until response to drug is known); nausea or vomiting, or loss of appetite (frequent small meals, frequent mouth care, chewing gum, or sucking lozenges may help); mild muscle discomfort (analgesics may be recommended). Report chest pain, palpitations, or erratic heartbeat; difficulty breathing or unusual cough; mental confusion or depression; muscle tremor, weakness, or pain; or changes in vision. Pregnancy/breast-feeding precautions: Inform prescriber if you are or intend to be pregnant. Do not breast-feed.

Monitor for tremor; titration of dosing and initiation of therapy require cardiac monitoring

Tablet, as hydrochloride: 400 mg, 600 mg

Denaro CP and Benowitz NL, "Poisoning Due to Class IB Antiarrhythmic Drugs: Lignocaine, Mexiletine, and Tocainide," Med Toxicol Adverse Drug Exp, 1989, 4(6):412-28.

Roden DM and Woosley RL, "Drug Therapy. Tocainide," N Engl J Med, 1986, 315(1):41-5.

Wiegers U, Hanrath P, Kuck KH, et al, "Pharmacokinetics of Tocainide in Patients With Renal Dysfunction and During Haemodialysis," Eur J Clin Pharmacol, 1983, 24(4):503-7.