CV Pharmacology | Cardiac Glycosides (Digitalis Compounds)
Digitalis toxicity occurs when you take too much digitalis, a medication The minerals potassium and magnesium are essential for . Wondering what to eat, how much, or just how to have a healthier relationship with food?. Digoxin is a medicine used to treat certain heart conditions. It can be used to treat congestive heart failure, a condition in which the heart muscle is weak and. DURING the past decade, the relationship between digitalis drugs and potassium has been from the onset of drug action through toxicity and death. Methods.
Pharmacokinetics and toxicity The long half-life of digitalis compounds necessitates special considerations when dosing.
- Hyperkalemia complicating digoxin toxicity in a patient with renal failure.
- Digitalis Toxicity: The Deadly Potential of Digitalis
- Digitalis toxicity
With a half-life of 40 hours, digoxin would require several days of constant dosing to reach steady-state, therapeutic plasma levels digitoxin with a half-life of hours, would require almost a month! Therefore, when initiating treatment, a special dosing regimen involving "loading doses" is used to rapidly increase digoxin plasma levels.
This process is termed "digitalization. It is very important that therapeutic plasma levels are not exceeded because digitalis compounds have a relatively narrow therapeutic safety window.
Plasma concentrations above 2. If toxicity occurs with digoxin, it may take several days for the plasma concentrations to fall to safe levels because of the long half-life.
There is available for digoxin toxicity an immune Fab Digibind that can be used to rapidly reduce plasma digoxin levels. Potassium supplementation can also reverse the toxic effects of digoxin if the toxicity is related to hypokalemia see below.
Drug Interactions Many commonly used drugs interact with digitalis compounds. The Class IA antiarrhythmic, quinidinecompetes with digoxin for binding sites and depresses renal clearance of digoxin. These effects increase digoxin levels and can produce toxicity. Similar interactions occur with calcium-channel blockers and nonsteroidal anti-inflammatory drugs.
Other drugs that interact with digitalis compounds are amiodarone Class III antiarrhythmic and beta-blockers.
Diuretics can indirectly interact with digoxin because of their potential for decreasing plasma potassium levels i. Hypercalcemia enhances digitalis-induced increases in intracellular calcium, which can lead to calcium overload and increased susceptibility to digitalis-induced arrhythmias. Hypomagnesemia also sensitizes the heart to digitalis-induced arrhythmias.
Your body could also become swollen. A severe case of DT is dangerous because it can cause your heart to beat too quickly, too slowly, or irregularly.
Heart failure is a significant risk of DT and can be life-threatening. Your doctor will ask questions about the type of digitalis you take and your current dosage. The following tests may also be necessary to diagnose the condition: Breathing Assistance If you are having trouble breathing, breathing machines may help. If your heart is beating too slowly or irregularly, you may be given medication or electric shock therapy cardioversion.
Hyperkalemia complicating digoxin toxicity in a patient with renal failure.
Stomach and Blood Cleaning To treat toxicity, your doctor might pump your stomach by inserting a tube down your throat. You might also be asked to take charcoal tablets to lower the level of digitalis in your blood.Pharmacology Tips for Nurses: Digoxin
If your condition is extreme, your doctor may use a method called hemodialysis blood filtering. This will remove digitalis from your blood.
Specific antibodies may also be prescribed to target and lower digitalis levels in your body. To prevent the condition, monitor your intake of digitalis medications.
A doctor must regularly check the amount of the drug in your blood, especially if you have other conditions, such as a kidney problem. Doses of digitalis that are normal for others may be toxic for you. It depends on your body chemistry and general health.