Digoxin: Difference between revisions
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==General== | ==General== | ||
*Type: Cardiac glycoside; [[CHF medications]] | *Type: Cardiac glycoside; [[CHF medications]] | ||
*Mechanism of action- Inhibits Na+/K+ ATPase, leading to an increase in intracellular sodium that can increase cardiac contractility | |||
*Dosage Forms: PO, IV, IM | *Dosage Forms: PO, IV, IM | ||
*Common Trade Names: Digitek, Digox, Lanoxin | *Common Trade Names: Digitek, Digox, Lanoxin | ||
==Adult Dosing== | ==Adult Dosing== | ||
*Loading dose = 0.25mg IV q2hr until effect (max total = 1.5mg) | *Loading dose = 0.25mg IV q2hr until effect (max total = 1.5mg) | ||
*in acute | *in acute [[atrial fibrillation with RVR]] with heart failure = 0.5mg IV, then 0.25mg IV q4hr until effect or max 1.5mg | ||
==Pediatric Dosing== | ==Pediatric Dosing== | ||
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*GI: nausea and vomiting, diarrhea, abdominal pain | *GI: nausea and vomiting, diarrhea, abdominal pain | ||
*CV: Bradycardia, SA/AV block, ventr arrhythmias | *CV: Bradycardia, SA/AV block, ventr arrhythmias | ||
*Neuro: [[altered mental status]], visual disturbances (yellow-tinted vision) | |||
==Pharmacology== | ==Pharmacology== | ||
*Half-life: | *Onset of action | ||
*Metabolism: | **IV = 5-30 minutes | ||
*Excretion: | **PO = 0.5-2 hours | ||
*Half-life: 36-48 hours (may be increased with renal impairment) | |||
*Absorption: 60-80% absorption after oral administration | |||
*Metabolism: ~16% is converted to metabolites | |||
*Excretion: Almost entirely by the kidneys | |||
==Mechanism of Action== | ==Mechanism of Action== | ||
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<references/> | <references/> | ||
[[Category:Pharmacology]] | [[Category:Pharmacology]] | ||
[[Category:Cardiology]] | |||
Latest revision as of 21:17, 6 January 2022
General
- Type: Cardiac glycoside; CHF medications
- Mechanism of action- Inhibits Na+/K+ ATPase, leading to an increase in intracellular sodium that can increase cardiac contractility
- Dosage Forms: PO, IV, IM
- Common Trade Names: Digitek, Digox, Lanoxin
Adult Dosing
- Loading dose = 0.25mg IV q2hr until effect (max total = 1.5mg)
- in acute atrial fibrillation with RVR with heart failure = 0.5mg IV, then 0.25mg IV q4hr until effect or max 1.5mg
Pediatric Dosing
Special Populations
- Pregnancy Rating: C
- Lactation risk:
- Renal Dosing
- Adult
- Pediatric
- Hepatic Dosing
- Adult
- Pediatric
Indications
- RVR control in a-fib/flutter, PSVT
Contraindications
- Allergy to class/drug
- WPW
- Increases conduction velocity in atrial tissue
Adverse Reactions
- GI: nausea and vomiting, diarrhea, abdominal pain
- CV: Bradycardia, SA/AV block, ventr arrhythmias
- Neuro: altered mental status, visual disturbances (yellow-tinted vision)
Pharmacology
- Onset of action
- IV = 5-30 minutes
- PO = 0.5-2 hours
- Half-life: 36-48 hours (may be increased with renal impairment)
- Absorption: 60-80% absorption after oral administration
- Metabolism: ~16% is converted to metabolites
- Excretion: Almost entirely by the kidneys
Mechanism of Action
- Inhibits Na+/K+ ATPase in the myocardium[1]
- Causes increase in intracellular sodium levels
- Results in reversal of sodium-calcium exchanger
- Normally imports three extracellular sodium ions into the cardiac myocyte in exchange for one intracellular calcium being exported
- Sodium accumulates intracellularly and is exchanged for Calcium.
- Causes an increase in the intracellular calcium concentration increasing contractility
- Also a lengthening of phase 4 and phase 0 of the cardiac action potential which ultimately decreases heart rate
- Summary
- Inhibits NaK pump
- Positive inotropy
- Negative chronotropy/dromotropy
- Indirect vagal stimulator
- Inhibits NaK pump
Comments
See Also
References
- ↑ Gheorghiade M. et al. Digoxin in the Management of Cardiovascular Disorders. Circulation. 2004; 109: 2959-2964