Generality
Digoxin is an active ingredient used to increase the strength of cardiac contraction .
In detail, digoxin is a molecule of natural origin belonging to the class of digitalis glycosides, particular compounds so called because they are identified and isolated from plants belonging to the genus Digitalis ( Digitalis lanata and Digitalis purpurea ).
Digoxin is used for the treatment of cardiac disorders for which it is necessary to increase the strength of contraction of myocardial fibers both atrial and ventricular (positive inotropic action). In addition to the positive inotropic action, digoxin is also able to exert a negative chronotropic action (decrease in heart rate).
Digoxin is available in pharmaceutical formulations suitable for oral use (tablets, capsules and syrup) and suitable for parenteral administration (solution for injection).
Dispensing of digoxin-containing medicines can only take place upon presentation of a repeatable medical prescription .
Examples of Specialties Medicines containing Digoxin
- Lanoxin®
- Eudigox®
Therapeutic indications
When is Digoxin Use Indicated?
The use of digoxin is indicated in the following cases:
- Treatment of chronic heart failure with prevalent systolic anomaly;
- Treatment of atrial fibrillation;
- Treatment of chronic atrial flutter;
- Treatment of paroxysmal atrial tachycardia.
Warnings
Warnings and Precautions for the use of Digoxin
Before starting treatment with digoxin, it is advisable to inform your doctor if you are in one or more of the following conditions that could preclude taking the active ingredient or otherwise require special attention:
- Recent heart attack;
- Presence of hypokalemia, hypomagnesemia and / or hypoxia;
- Presence of hypercalcemia;
- Presence of heart failure associated with cardiac amyloidosis (accumulation of amyloid protein inside the heart muscle);
- Presence of myocarditis;
- Presence of obstructive pericarditis
- Vitamin B1 deficiency and presence of beriberi disease;
- Respiratory problems;
- Presence of malabsorption syndrome;
- Previous surgical interventions in the intestine.
However, as a precautionary measure, before taking digoxin-based medicines, it is always advisable to inform your doctor of your health conditions, making it aware of the possible presence of any type of disorder or illness, even if not present in the aforementioned list.
Please note
The administration of digoxin can cause side effects that can alter the ability to drive vehicles and / or use machines (dizziness, visual disturbances, etc.). Therefore, great caution is recommended.
Furthermore, it is noted that digoxin can alter the results of the effort electrocardiogram.
Pharmacological Interactions
Interactions between Digoxin and Other Drugs
Digoxin can establish drug interactions with multiple drugs, for this reason, before starting therapy with this active ingredient, it is necessary to inform your doctor if you are taking, or have recently been taken, drugs such as:
- Antiarrhythmic drugs;
- Antianginal drugs;
- Calcium channel blockers;
- Medicines for the treatment of hypertension;
- Diuretics;
- Antidepressant drugs;
- Anxiolytic drugs;
- Antibiotics, such as tetracycline, macrolides and aminoglycoside antibiotics;
- Antiviral drugs;
- Antifungal drugs;
- Steroidal anti-inflammatories (corticosteroids);
- Diabetes care drugs;
- Anti-cancer drugs;
- Statins;
- antiasthmatics;
- Antiplatelet drugs;
- Drugs used to treat gastrointestinal disorders such as indigestion, vomiting and diarrhea;
- Drugs containing sennosides;
- Penicillamine for the treatment of rheumatoid arthritis;
- Ivacaftor (used in the treatment of cystic fibrosis);
- Mirabegron (used in the treatment of overactive bladder);
- Epoprostenol (a prostaglandin used in the treatment of pulmonary arterial hypertension);
- St. John's wort (or St. John's wort, if you prefer, famous for its antidepressant properties) and products that contain it.
In any case, before starting digoxin therapy, it is necessary to tell the doctor if you are taking - or if you have recently been taken - drugs or products of any kind, including medicines without a prescription (SOP). ), OTC drugs, herbal and herbal products and homeopathic products.
Side effects
Side Effects Caused by Digoxin Intake
Digoxin, like any other active ingredient, is able to cause different side effects, even if not all patients manifest them or manifest them in the same way. In fact, each individual reacts subjectively to the administration of the active ingredient in question, manifesting side effects of different types and / or intensity, or not manifesting them at all.
The following are some of the main side effects that could occur during drug treatment with digoxin.
Cardiac disorders
Digoxin treatment could lead to side effects affecting the heart, such as:
- Conduction disorders;
- arrhythmias;
- Sinus bradycardia;
- Prolongation of the PR interval;
- Bigeminism and trigeminism (these are cardiac rhythm abnormalities);
- Supraventricular tachyarrhythmia;
- Atrial tachycardia;
- Ventricular extrasystoles.
Gastrointestinal disorders
Digoxin-based therapy could cause digestive disorders such as:
- Nausea and vomit;
- Diarrhea;
- Intestinal necrosis;
- Gastrointestinal ischemia.
Please note
Sometimes the appearance of nausea and / or vomiting may precede the onset of cardiac arrhythmias. However, this does not always occur.
Psychiatric disorders
The administration of digoxin could favor the appearance of psychiatric disorders such as:
- Depression;
- Psychotic disorders;
- Apathy.
Nervous system disorders
Digoxin treatment could induce:
- Headache;
- Dizziness;
- Confusional states;
- Other disorders of the nervous system.
Other side effects
Other possible side effects resulting from digoxin intake consist of:
- Allergic reactions, even serious, in sensitive individuals;
- Skin rash;
- Vision disorders;
- Malaise and fatigue;
- Asthenia;
- Loss of appetite;
- Thrombocytopenia;
- Gynecomastia;
- Reactions at the injection site (when digoxin is administered parenterally).
Overdose
In the event of excessive doses of digoxin, the following symptoms may occur:
- arrhythmias;
- Slow atrial fibrillation;
- Atrioventricular block;
- Nausea and vomit;
- Dizziness;
- Fatigue;
- Malaise;
- Changes in vision;
- Nervous system disorders.
The treatment of digoxin overdose may be different depending on the case: it is possible to administer activated charcoal - even in large quantities - and / or resort to performing gastric lavage . In some cases, the doctor may decide to resort to the administration of antidigital antibody fragments .
Given the severity of the symptoms that can occur and the type of treatment to be subjected to, in the event of intake - suspected or ascertained - of excessively high doses of digoxin, it is best to go to the nearest emergency room carrying the specialty pack. medicine containing digoxin that was taken.
Action mechanism
How does Digoxin work?
Digoxin carries out its activity of increasing myocardial contractility through direct action . More specifically, this active ingredient is able to bind to the membrane Na + / K + ATPase pump causing its inhibition, with a consequent increase in intracellular sodium levels . This increase reduces the concentration gradient between the intracellular sodium and the extracellular sodium with consequent activation of the sodium-calcium exchangers which provide to extrude sodium ions from the cell and to introduce calcium ions . In this way, there is an increase in the levels of intracellular calcium ions which leads to an increase in myocardial contractility.
Method of use and Posology
How to take Digoxin
As mentioned, digoxin is available within different pharmaceutical formulations suitable for oral administration - tablets, capsules and syrup - and for parenteral administration .
The choice to use digoxin orally rather than digoxin parenterally must be taken by the doctor who will evaluate, case by case, the most appropriate method of administration for each patient. The same applies to the dosage of the active ingredient which will be established by the doctor on the basis of the patient's age and body weight and according to his renal function.
However, tablets and capsules should be swallowed whole with a little water, the syrup should be drunk as it is and the solution for injection should be administered by competent personnel.
Pregnancy and breastfeeding
Can Digoxin be taken in pregnancy and during breastfeeding?
The state of pregnancy and breastfeeding do not represent real contraindications to the use of digoxin. However, the active ingredient in question should only be used if strictly necessary and only under strict medical supervision .
However, if digoxin is to be administered to pregnant women, it is likely that the dosage normally used will be decreased by the doctor.
Contraindications
When Digoxin Should Not Be Used
The use of digoxin is contraindicated in the following cases:
- Known hypersensitivity to digoxin itself and / or to any of the excipients contained in the medicinal product to be used;
- In the presence of complete intermittent heart block;
- In the presence of second degree atrioventricular block;
- In case of marked hypokalemia;
- In patients who experience arrhythmias induced by cardioactive glycoside-based therapies such as digoxin;
- In the presence of supraventricular arrhythmias, ventricular tachycardia or ventricular fibrillation;
- In patients suffering from hypertrophic obstructive cardiomyopathy.
