Digoxin vs. dobutamine

• Digoxin and dobutamine are used to treat different heart conditions.
• Digoxin is used for treating adults with mild to moderate congestive heart failure and for treating abnormally rapid atrial rhythms (atrial fibrillation, atrial flutter, atrial tachycardia). It also is used for increasing myocardial contractility in pediatric patients with heart failure.
• Dobutamine is used to help increase cardiac output in a failing heart due to heart disease or cardiac surgery.
• Brand names for digoxin include Lanoxin and Lanoxin Pediatric.
• Digoxin and dobutamine belong to different drug classes. Digoxin is a cardiac glycoside and dobutamine is a synthetic catecholamine.
• Side effects of digoxin and dobutamine that are similar include nausea and headache.
• Side effects of digoxin that are different from dobutamine include vomiting, diarrhea, dizziness, skin rash, and mental changes.
• Side effects of dobutamine that are different from digoxin include increased heart rate, increased blood pressure, irregular ventricular beats, chest pain, fever, and shortness of breath.

Digoxin is a cardiac glycoside used to treat adults with mild to moderate congestive heart failure and to treat abnormally rapid atrial rhythms (atrial fibrillation, atrial flutter, atrial tachycardia). It also is used to increase heart contractions in pediatric patients with heart failure. Digoxin increases the force of contraction of the heart muscle by limiting the activity of ATPase, an enzyme that controls the movement of calcium, sodium, and potassium into heart muscle. Inhibiting ATPase increases calcium in the heart muscle and increases the force of heart contractions. Digoxin also slows electrical conduction between the atria and the ventricles of the heart and is used in treating abnormally rapid atrial rhythms.

Dobutamine is a synthetic catecholamine that is prescribed to help increase cardiac output in a failing heart due to heart disease or cardiac surgery. Dobutamine injection is indicated when parenteral therapy is necessary for inotropic support in the short-term treatment of adults with cardiac decompensation due to depressed contractility resulting either from organic heart disease or from cardiac surgical procedures. In patients who have atrial fibrillation with rapid ventricular response, a digitalis preparation should be used prior to institution of therapy with dobutamine hydrochloride.

Digoxin

Common side effects include:

• nausea,
• diarrhea,
• vomiting,
• headache,
• dizziness,
• skin rash, and
• mental changes.

Many digoxin side effects are dose dependent and happen when blood levels are over the narrow therapeutic range. Therefore, digoxin side effects can be avoided by keeping blood levels within the therapeutic level. Serious side effects associated with digoxin include:

• heart block,
• rapid heartbeat, and
• slow heart rate.

Digoxin has also been associated with visual disturbance (blurred or yellow vision), abdominal pain, and breast enlargement. Patients with low blood potassium levels can develop digoxin toxicity even when digoxin levels are not considered elevated. Similarly, high calcium and low magnesium blood levels can increase digoxin toxicity and produce serious disturbances in heart rhythm.

Dobutamine

The most frequent adverse reactions include:

• increased heart rate,
• increased blood pressure,
• irregular ventricular beats, and
• chest pain.

Other important side effects include:

• fever,
• headache,
• nausea, and
• shortness of breath.

Serious side effects of dobutamine include:

• abnormal heartbeats,
• increased heart rate,
• low blood pressure,
• chest pain,
• fainting, and
• eosinophilic myocarditis.

Digoxin

• Digoxin may be taken with or without food.
• Digoxin primarily is eliminated by the kidneys; therefore, the dose of digoxin should be reduced in patients with kidney dysfunction.
• Digoxin blood levels are used for adjusting doses in order to avoid toxicity.
• The usual starting dose is 0.0625-0.25 mg daily depending on age and kidney function.
• The dose may be increased every two weeks to achieve the desired response.
• The usual maintenance dose is 0.125 to 0.5 mg per day.

Dobutamine

• The initial dose for adults is based on the indication and severity of heart failure.
• Dosing is 0.5 to 1 micrograms per kilogram body weight per minute followed by an intravenous infusion of 2 to 20 micrograms per kilogram body weight per minute.
• Maximum dose is 40 micrograms per kilogram per minute.

Digoxin

• Drugs such as gentamicin, tetracycline, ranolazine (Ranexa), verapamil (Calan, Verelan, Verelan PM, Isoptin, Isoptin SR, Covera-HS), quinidine (Quinaglute, Quinide), amiodarone (Cordarone), indomethacin (Indocin, Indocin-SR), alprazolam (Xanax, Xanax XR, Niravam), spironolactone (Aldactone), and itraconazole (Sporanox) can increase digoxin levels and the risk of toxicity. The co-administration of digoxin and beta-blockers (for example propranolol [Inderal, Inderal LA]) or calcium channel blockers or CCBs (for example, verapamil), which also reduce heart rate, can cause serious heart rate slowing.
• Diuretic-induced (for example, by furosemide [Lasix]) reduction in blood potassium or magnesium levels may predispose patients to digoxin-induced abnormal heart rhythms.
• Saquinavir (Invirase) and ritonavir (Norvir) increase the amount of digoxin in the body and may cause digoxin toxicity.
• Mirabegron (Mybetriq) increases digoxin blood levels. The lowest dose of digoxin should be used if by people who are also using mirabegron.
• Omeprazole (Prilosec) and other drugs that reduce stomach acidity may increase blood levels of digoxin.

Dobutamine

• Use caution when combining dobutamine with other agents that increase heart rate or blood pressure (sympathomimetics), such as atomoxetine (Strattera), dopamine, and epinephrine.
• Use lower doses of dobutamine initially if the patient is also on linezolid (Zyvox) as there is a risk of significant increase in blood pressure.
• Calcium salts may decrease the effect of dobutamine, so monitor closely.

Digoxin

• There are no adequate studies in pregnant women.
• Digoxin is secreted in breast milk at concentrations similar to concentrations in the mother’s blood. However, the total amount of digoxin that will be absorbed from breast milk by the infant may not be enough to cause effects. Nursing mothers should exercise caution if they are taking digoxin.

Dobutamine

• Available evidence suggests that dobutamine may be safely used in pregnancy.
• Nursing mothers should use caution if they are taking dobutamine, as it is unknown whether it is excreted in breast milk.