[The antitoxic action of triamterene in cardiac glycoside poisoning]
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Abstract:
The antagonistic effect of triamterene on the toxicity of cardiac glycosides was investigated in conscious rabbits using the infusion method. Pretreatment with triamterene (5 mg/kg and 10 mg/kg) significantly reduces the ouabain toxicity indicated by an increase of the dose producing arrhythmia (from 61 +/- 14 to 121 +/- 17 and 178 +/- 22 micrograms/kg, resp.) and lethality (from 114 +/- 18 to 236 +/- 5 and 329 +/- 11 micrograms/kg, resp.). The triamterene induced increase of plasma potassium concentration may contribute to the antitoxic effect, however, the effect persisted after the decrease of plasma potassium concentration (by addition of NaHCO3) to pretreatment values. Under the influence of digitoxin the antitoxic effect of triamterene (10 mg/kg) is also demonstrated by the delayed appearance of arrhythmias (113 +/- 3 min compared to 78 +/- 5 min) and of lethality (125 +/- 4 min compared to 92 +/- 6 min). Triamterene is not only a prophylactic but also a curative antitoxic agent in the digitalis intoxicated rabbit.
Insights
Triamterene significantly reduces cardiac glycoside toxicity in rabbits, acting both preventatively and curatively. This effect, observed with ouabain and digitoxin, suggests triamterene as a potential antidote for digitalis intoxication.
Area of Science:
- Pharmacology
- Toxicology
- Cardiovascular Research
Context:
- Cardiac glycosides, like ouabain and digitoxin, are potent drugs with a narrow therapeutic index.
- Digitalis toxicity poses a significant clinical challenge, necessitating effective antidote strategies.
- Triamterene, a potassium-sparing diuretic, has been investigated for its potential cardioprotective effects.
Purpose:
- To investigate the antagonistic effect of triamterene on the toxicity of cardiac glycosides in a conscious rabbit model.
- To determine if triamterene can mitigate ouabain- and digitoxin-induced arrhythmias and lethality.
- To explore the role of plasma potassium levels in triamterene's antitoxic mechanism.
Summary:
- Triamterene pretreatment (5 and 10 mg/kg) significantly increased the doses of ouabain required to induce arrhythmia and lethality in rabbits.
- The antitoxic effect of triamterene was also observed with digitoxin, delaying the onset of arrhythmias and lethality.
- While increased plasma potassium may contribute, triamterene's protective effect persisted even after normalizing potassium levels.
Impact:
- Triamterene demonstrates both prophylactic and curative properties against digitalis toxicity in rabbits.
- These findings suggest triamterene as a potential therapeutic agent for managing cardiac glycoside poisoning.
- Further research may elucidate the precise mechanisms underlying triamterene's cardioprotective actions in digitalis toxicity.