Antiarrhythmic agents include-

Group I -  Moricizine, Qunidine, Procainamide, Disopyramide, Lidocaine, Phenytoin,

                 Tocainide,  Mexiletine, Flecanide, Propafenone
Group II- Propranolol, Esmolol, Acebutol
Group III- Bretylium, Amiodarone, Solatol
Group IV- Verapramil, Digoxin, Adenosine

Interacting drugs- summary
 

+ Tocainide-

Cimetidine +
Tocainide bioavailability and peak concentration may be decreased;
 rantidine does not appear to affect tocainide

Metroprolol  +
These agents have additive effects on wedge pressure and cardiac
 index

Rifampin +
Tocainides elimination half-life, bioavailability may be decreased;
  oral clearance may be increased      
       

Treatment of life-threatening ventricular arrhythmias
 

Antiarrhythmic agents include-

Group I -  Moricizine, Qunidine, Procainamide, Disopyramide, Lidocaine, Phenytoin,

                Tocainide,  Mexiletine, Flecanide, Propafenone
Group II- Propranolol, Esmolol, Acebutol
Group III- Bretylium, Amiodarone, Solatol
Group IV- Verapramil, Digoxin, Adenosine

Most frequent-
Dizziness, vertigo,  ( 15) ,Nausea ( 14% ) , Paraethesia ( 9%% ) Tremor ( 8% )

These reactions were generally mild,. transcient, dose-related and reversible with a reduction in dosage, by taking the drug with food or by disconitinuation of therapy.
Adverse reactions leading to discontinuation of therapy occurred in 21% of patients 
and were related to CNS or GI system 

BODY AS A WHOLE -    Tiredness/drowsiness/fatigue/lethargy/ lassitude/sleepiness  2%
                                         Hot/cold feelings   rare

CARDIOVASCULAR -    Hypotension 3% Bradycardia,  Palpitations  2% Chest pain 2%
                                         Conduction disorders, Left ventricular failure 1%

GI                                -    Nausea 15%, Vomiting 8%, Anorexia 1 %

CNS                            -    Dizziness/vertigo  8%, Parathesia 4%, Tremor 3%,
                                         Confusion, Hallucinations, Headache 2%
                                         Nervousness/weakness, Altered mood, Awareness,

                                          Unsteadiness/Walking disturbances  1%   Anxiety 1%

SKIN -                              Diaphoresis 5%,

SPECIAL SENSES-        Blurred vision/ visual disturbances 1%                
      

Hypersensitivity to tocainamide or to amide-type local anesthetics;

patients with second degree AV block in the absence of an artificial ventricular pacemaker.

Special precautions:

Hyperkalemia- since antiarrhythmic drugs may be ineffective in patients with hypokalemia correct potassium defecits if present

Warnings-

Proarrhythmias- like other oral antiarrhthmics tocainde mauy increae arrhythmias in some patients

Cardiac effects- evaluate each patient by ECG and clinically prior to and during therapy to determine if response to tocainmide supports continued treatment.

Accelration of ventricular rate- occurs infrequently when tocainide is administered to patients with atrial flutter or fibrilation.

Renal/hepatic function impairment- in patients with severe liver or kidney disease the rate of drug eliminatin may be significantly decreased

Pregnancy- use during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Lactation- because of the potential for serious advese reactions, decide whether to discontinue nursing or drug, taking into account importance of drug to the mother.

Children- safety and efficacy for use in children have not been established.

Approved by FDA in 1984 Indications:

Indication-

Treatment of life-threatening ventricular arrhythmias

Dosage:

Initial 400mg every 8 hours, range is 1200 to 1800mg/day given in 3 divided doses.

Overdosage- Symptoms

Treatment-

The initial and most important signs and symptoms

1. If convulsions or respiratory expression develop, of overdosage are usually realted to CNS. Tremor immediately assure that patency of the airway and may indicate that the maximum dose is being adequacy of ventilation. approached. Other adverseractions such as GI

2. Gastric lavage and administration of charcoal, give distuebances amy follow. small increments of anticonvulsant IV.

3. Examples of such agents include a benzodiazepine eg. diazepam, an ultra short-acting barbiturate eg. thiopental, thiamylal, or a short acting barbiturate, secobarbital

4. Hemodilalysis claerance is approximaetely equivalent to renal clearance.

Missed dose-

 1. If you miss a dose of this medicine, take it as soon as possible unless the dose is less than 4 hours.

2. However, if you do not remember until later, skip the missed dose and go back to your regular dosing schedule.

3. Do not double doses.

TOCAINIDE-

1. Notify physician if any of the following occurs; external dyspenea, cough, wheezing, tremor, palpitations, rash, easy bruising, or bleeding, fever, sore throat, soreness and ulcers in the mouth or chills.

2. May cause drowsiness or dizziness. Observe caution while driving or performing other tasks requiring alertness, coordination or physical dexterity.

3. May cause nausea, vomiting, or diarrhea. Notify physician if these become severe.

4. Allergy- tell your doctor if you ever had any allergic reaction to tocanide or any anesthetics or any other substances such as food, preservatives or dyes.

5. Pregnancy- not studied in pregnant women. However this medicine has shown that high dose of tocainide may icrease the possiblity of death in animal fetus

 6. Breast feeding- tocainide may pass into breast milk . Mothers who are taking this medicine and who wish to breast feed should discuss this with their doctor.

7. Children- studies on this medicine has been done only on adult patients,and there is no specific information comparing use of tocainide in children with use in other age groups.

8. Older adults- dizziness orlightheadedness may be more likelyto occur in the elderly, who are usually more sensitive to the effects of tocainide

9. Other medicines- tell your doctor if you are taking any other prescription drugs or non-prescription drugs OTC medicines.

10. Other medical problems- tell your doctor if you any other medical problems especially- Congestive heart failure - tocainide may make this condition worse. Kidney disease or Liver disease -effects may be incr because of slower removal of tocainide from the body.

11. Dosing- dose of tocainide may be different for different patients. Follow yourdoctors advice

12. Missed dose - If you miss a dose of this medicine, take it as soon as possible. however, if it is almost time for the next dose, skip the missed dose. Do not double doses.

13. Storage - Keep out of reach of children. Store away from heat or direct sunlight. Do not store the capsule in bathroom, near the kitchen sink, or in other damp places.

11. Date Expired  medicines - Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of reach of children.

Pharmacology:

Tocainide, like lidocaine, produces dose-dependent decreases in sodium and potassium conductance, therby decreasing the excitability of myocardial cells. Most patients who respond to lidocaine also respond to tocainide.

Pharmacokinetics:

Following oral administration the bioavailability of tocainide approaches 100%, peak serum concentrations are attained in 0.5 to 2 hours The extent of bioavialabilty is unaffected by food. Inactivated via conjucaton in the liver.

The average plasma half-life is about 15 hours. About 40% is excreted unchanged in urine.

Not significant

Pregnancy:

Use during pregnancy only if needed.

Lactation:

Observe caution, because of the potential for serious adverse reactions.

Children:

Safety and efficacy for use in children have not been established.