Class 1B arrhythmia (lidocaine, mexiletine ) pharmacological action, uses , side effects, precautions)
Pharmacological action:
Classified as Sodium channel blockers ...
- The most important thing here is not to allow sodium to enter in order to reduce the depolarization period and speed up the time of the stroke, meaning that some people have a long stroke and others do not exist at all.
- successful in the event of very rapid and intense contractions, and its effect on the atrial is small and does not affect the conduction, so it is classified as low effectiveness.
Uses:
- Weak and unable to slow down conduction.
- It is not used as a first-line treatment.
- Combination therapy is used with any other effective drug for the treatment of arrhythmia.
side effects:
lidocaine :
- often given (IV) so that it does not first pass metabolism , it takes time for symptoms to appear .
- involuntary eye movement.
- Slow speech.
- numbness in the extremes.
- convulsions.
- agitation.
- symptoms of CNS.
mexiletine:
- given orally, and its side effects appear faster (narrow therapeutic index).
- GIT side effects N, V, D.
drug - drug interactions :
- Beta blockers affect the amount of blood that goes to the liver as it reduces it, especially lidocaine, since the metabolism is decrease through the liver causes toxicity to accumulate in the blood and the heart rate decreases, you must pay attention to the dose of lidocaine .
- It should not be given to people who have problems with the liver, because this leads to the toxicity of the drug will increase, and the side effects will increase.