文档介绍：洋地黄中毒
第一页，课件共24页
Digitalis Intoxication
Cardiac glycoside poisoning is a potentially life-threatening problem
In a series of 150 severely affected patients
50 % were receiving long-term digitalis therapy,
10 %had taken an accidental large overdose, and
40 % had ingested an overdose with suicidal intent
Treatment of 150 cases of life-threatening digitalis intoxication with digoxin-specific Fab antibody fragments. Final report of a multicenter study.
Circulation 1990; 81:1744
第二页，课件共24页
Digitalis Intoxication
The mortality in different studies has ranged from 3 to 40 percent
Recent advances have considerably lowered the incidence of digitalis overdose in patients receiving chronic therapy. These include:
A better understanding of pharmacokinetics, leading to more appropriate maintenance dosing
Increasing awareness of drugs that can affect digoxin metabolism
The development of radioimmunoassays for plasma digoxin levels
第三页，课件共24页
PHARMACOLOGY
Digitalis acts at the subcellular level by inhibiting the membrane-bound Na-K-ATPase pump
The net effect is the intracellular loss of potassium and the gain of sodium and calcium
Drug action depends on the tissue conc., which is relatively constant in relation to plasma levels
Thus, plasma levels can be used to monitor compliance and toxicity
第四页，课件共24页
PHARMACOLOGY
The two digitalis preparations used in clinical practice today are digoxin and digitoxin
The bioavailability of digoxin is about 80 % and plasma half-life is days
Major depot for digitalis in humans is skeletal muscle
As a result, dosage requirements and the likelihood of toxicity are related to muscle mass rather than total body weight
Approximately one-third of the body stores of digoxin is excreted per day – 30 % unchanged in the urine, and 3 % as metabolites in stool
第五页，课件共24页
PREDISPOSING FACTORS TO TOXICITY
Drug Interactions
A number of drugs can raise digitalis levels by interfering with its metabolism or renal excr