Tocainide HCl

A to Z Drug Facts

 Action Produces dose-dependent decreases in sodium and potassium conductance resulting in decrease in myocardial cell excitability.

 Indications Treatment of life-threatening ventricular arrhythmias. Unlabeled use(s): Treatment of myotonic dystrophy and trigeminal neuralgia.

 Contraindications Hypersensitivity to tocainide or amidetype local anesthetics; second-or third-degree atrioventricular block in absence of artificial ventricular pacemaker.

 Route/Dosage

ADULTS: PO 400 mg q 8 hr initially. Maintenance: 1200–1800 mg/day in 3 divided doses.

 Interactions

Cimetidine: May decrease tocainide bioavailability and peak concentration. Rifampin: May decrease tocainide bioavailability and elimination half-life; may increase tocainide oral clearance.

 Lab Test Interferences None well documented.

 Adverse Reactions

CV: Increased ventricular arrhythmias; PVCs; CHF and progression of CHF; tachycardia; hypotension; bradycardia; palpitations; chest pain; conduction disorders. CNS: Dizziness; vertigo; paresthesias; tremor; nervousness; anxiety; confusion; eadache; seizures. DERM: Diaphoresis; systemic lupus erythematosus; rash; skin lesion. EENT: Visual disturbances; nystagmus; tinnitus; hearing loss. GI: Nausea; vomiting; anorexia; diarrhea. HEMA: Anemia; leukopenia; thrombocytopenia; aplastic anemia; agranulocytosis. HEPA: Increased LFT result; hepatitis; jaundice. RESP: Respiratory arrest; pulmonary fibrosis; pulmonary edema; dyspnea. OTHER: Arthritis or arthralgia; myalgia; increased creatine phosphokinase.

 Precautions

Pregnancy: Category C. Lactation: Excreted in breast milk. Children: Safety and efficacy not established. Blood dyscrasias: Have occurred, with some fatalities. Blood tests are required weekly for first 3 mo, and frequently thereafter. Cardiac effects: Use drug with caution and in lower doses in patients with CHF or reduced cardiac output. Hypokalemia: Should be corrected prior to initiation of tocainide therapy to ensure efficacy. Proarrhythmia: Tocainide has proarrhythmic effect. Pulmonary fibrosis: Has occurred, as have other pulmonary complications. Promptly report any pulmonary symptoms. Renal or hepatic impairment: Use drug with caution in patients with renal or hepatic impairment. Dosage reduction and modified dosing intervals may be required.

 Administration/Storage

• Administer orally and preferably with food to avoid GI upset.
• Check with physician regarding early adverse effects. In some cases they can be decreased by administering medication with food or in smaller, more frequent doses.
• Store at room temperature away from sunlight and moisture.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies.
• Monitor and record CBC, including WBC with differential and platelets and LFTs weekly for first 3 mo and frequently thereafter.
• Assess pulmonary function, and report cough, dyspnea, wheezing or rales.
• Assess neurologic status, and report paresthesia or tremor.
• Review blood studies. Report hypokalemia to physician.
• Monitor vital signs, especially pulse and BP and report changes.
• Monitor I&O, and report urinary retention.
• Assess ECG prior to and during therapy.

 Patient/Family Education

• Advise patient that physician may require blood tests weekly for first 3 wk of treatment and frequently thereafter; caution against skipping appointments.
• Tell patient to report persistent or severe nausea, vomiting, diarrhea or loss of appetite immediately.
• Explain that patient may experience tiredness, or hot/cold feelings, taste and smell perversions, joint or muscle aches, dizziness, anxiety or headache and to report symptoms if severe or persistent.
• Tell patient to report signs of infection immediately (chills, fever, sore throat, sore mouth, earache, cough, wheezing, difficulty breathing).
• Tell patient to report changes in heart rate, chest pain, tremors, confusion, visual disturbances, ringing or roaring in ears, profuse sweating, rash, numbness or tingling, slurred speech, dry mouth, yellow skin or whites of eyes, unusual bruising or bleeding or double vision.
• Explain that if dose is missed to take as soon as remembered. If close to next dose, skip dose. If more than one dose is missed, tell patient to contact physician.
• Tell patient not to store medication in bathroom.
• Advise patient that drug may cause drowsiness and dizziness and to use caution while driving or performing other tasks requiring mental alertness.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts