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| Clinical data | |
|---|---|
| Trade names | Tonocard | 
| Other names | Tocainamide | 
| AHFS/Drugs.com | Micromedex Detailed Consumer Information | 
| MedlinePlus | a601248 | 
| ATC code | |
| Pharmacokinetic data | |
| Bioavailability | 0.9-1 (oral) | 
| Protein binding | 10-20% | 
| Metabolism | glucuronidation (primary) | 
| Elimination half-life | 9-14 R, 13-20 S | 
| Excretion | 30-50% urine (unchanged) | 
| Identifiers | |
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| CAS Number | |
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| DrugBank | |
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| CompTox Dashboard (EPA) | |
| ECHA InfoCard | 100.050.441 | 
| Chemical and physical data | |
| Formula | C11H16N2O | 
| Molar mass | 192.262 g·mol−1 | 
| 3D model (JSmol) | |
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Tocainide (Tonocard) is a class Ib antiarrhythmic agent. It is no longer sold in the United States.
 
 Tocainide is a lidocaine derivative, that undergoes very less first pass metabolism. It occurs as two enantiomers. The R isomer is three times more potent than the S isomer. [5] Tocainide's oral bioavailability is almost 100%. [6] Plasma half-life generally lasts for 11.5-15.5 hours (13.5 ± 2 hours [7] ). In the blood, tocainide is 10-20% protein bound. [8] [6] The volume of distribution is 2.8-3.2 L/kg. [8] 31-45% is excreted unchanged in the urine. [8] The more active R-isomer is cleared faster in anephric patients (without kidneys) or those with severe kidney dysfunction. The main metabolite is tocainide carbamoyl ester glucuronlde. [9]
Rifampicin increases conversion of tocainide into its main metabolite, tocainide carbamoyl ester glucuronlde, [9] by inducing the glucuronosyl transferase enzyme that catalyzes glucuronidation of tocainide to produce that metabolite. Rifampicin also increases elimination rate and decreases oral clearance of tocainide. [10] Tocainide decreases plasma clearance of theophylline. [11]
Oral bioavailability is high (near complete), with low protein binding (≈10–20%) and renal excretion of a substantial unchanged fraction; metabolism proceeds largely via glucuronidation. Reported plasma half-life values are roughly in the 9–20 hour range, with known stereoselective differences between enantiomers. [12] [13]
Tocainamide (tocainide) emerged in the 1970s as an orally effective alternative to lidocaine for ventricular arrhythmias, with early uncontrolled and controlled studies in refractory patients. [14] [15] Accumulating reports of bone-marrow toxicity and other serious adverse events led to declining use and eventual withdrawal from some markets; in the United States, tocainide products were removed in 2003. [16] [17]