Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
DIGOXIN PEDIATRIC vs NALOXONE HYDROCHLORIDE AND PENTAZOCINE HYDROCHLORIDE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Inhibits sodium-potassium ATPase, increasing intracellular sodium, which promotes calcium influx via sodium-calcium exchanger, enhancing cardiac contractility. Also increases vagal tone, slowing AV conduction.
Pentazocine is a mixed agonist-antagonist opioid that binds to mu-opioid receptors (partial agonist) and kappa-opioid receptors (agonist), producing analgesia. Naloxone is a pure opioid antagonist that competitively blocks mu, kappa, and delta receptors; when administered orally, naloxone undergoes extensive first-pass metabolism, reducing systemic absorption and primarily blocking the effects of pentazocine if the combination is misused parenterally.
Heart failure (FDA-approved for pediatric patients with heart failure),Atrial fibrillation (off-label for rate control in pediatric patients)
Moderate to severe pain relief; combinations are used to reduce abuse potential.
For pediatric patients, digoxin pediatric dosing is weight-based; no standard adult dose. Typical pediatric loading dose: 10-12 mcg/kg orally divided every 6-8 hours, with maintenance: 5-10 mcg/kg/day divided every 12 hours. For infants <1 month, loading: 10-15 mcg/kg, maintenance: 4-6 mcg/kg/day. For children 1-24 months, loading: 15-20 mcg/kg, maintenance: 5-8 mcg/kg/day. For children >2 years, loading: 10-15 mcg/kg, maintenance: 3-5 mcg/kg/day.
Oral: One tablet (naloxone 0.5 mg / pentazocine 50 mg) every 3-4 hours as needed for pain; maximum 12 tablets daily.
Terminal elimination half-life in neonates is 35-70 hours, infants 18-30 hours, children 12-30 hours, and adults 36-48 hours; prolonged in renal impairment and hypothyroidism.
Pentazocine has an elimination half-life of 2-3 hours in healthy adults, which may be prolonged in patients with hepatic impairment. Naloxone has a terminal half-life of 0.5-1.5 hours in adults, with a rapid decline in plasma levels; the short half-life limits its duration of opioid antagonism.
Primarily renally excreted unchanged; minimal hepatic metabolism (mostly via reduction, hydrolysis, and conjugation in older children).
Pentazocine is metabolized primarily by hepatic conjugation (glucuronidation) and oxidation via CYP2C19 and CYP2D6; naloxone is extensively metabolized by the liver, primarily via glucuronidation (UGT2B7).
Renal excretion accounts for 50-70% of elimination as unchanged drug; biliary/fecal excretion accounts for 30-40%, primarily as metabolites; enterohepatic recirculation occurs.
Pentazocine is primarily metabolized in the liver and excreted in urine as conjugates of glucuronide and sulfate, with about 60% of a dose excreted renally within 24 hours as metabolites and unchanged drug (less than 5% unchanged). Naloxone undergoes extensive hepatic metabolism to naloxone-3-glucuronide, which is excreted renally; approximately 50% of a dose is excreted as conjugates in urine within 6 hours.
25% bound to serum albumin; binding decreases in uremia and hyperbilirubinemia.
Pentazocine: Approximately 35-65% bound to plasma proteins (mainly albumin). Naloxone: Approximately 32-45% bound to plasma proteins (mainly albumin).
Vd: 6-10 L/kg in infants and children, 5-7 L/kg in adults; large Vd indicates extensive tissue binding, particularly to cardiac muscle (Na+/K+-ATPase).
Pentazocine: Vd ~2-3 L/kg, indicating extensive tissue distribution. Naloxone: Vd ~2-3 L/kg, also indicating wide distribution.
Oral: 60-80% (elixir 70-85%, tablets 60-75%); IM: 70-85% (but erratic absorption and pain limit use); IV: 100%.
Oral pentazocine: 20-30% due to first-pass metabolism. Intramuscular pentazocine: 100%. Subcutaneous pentazocine: 100%. Oral naloxone: <2% due to extensive first-pass metabolism. Intramuscular and subcutaneous naloxone: 100%. Intravenous: 100% for both.
Digoxin is primarily renally excreted. For pediatric patients, if GFR <30 m L/min/1.73m2, reduce maintenance dose by 50% and monitor serum levels. For GFR 30-60, reduce dose by 25-50%. In neonates with renal impairment, dose reduction proportional to creatinine clearance.
GFR 30-50 m L/min: Administer every 6 hours; GFR 10-29 m L/min: Administer every 8-12 hours; GFR <10 m L/min: Administer every 12 hours or consider alternative.
Digoxin is minimally hepatically metabolized; no dose adjustment required for hepatic impairment. However, in Child-Pugh class C, monitor levels due to potential altered distribution.
Child-Pugh Class A: No adjustment; Child-Pugh Class B: Reduce dose by 50% or extend interval; Child-Pugh Class C: Avoid use.
See standard_dosing. Weight-based dosing: total digitalizing dose (TDD) and maintenance as above. For premature infants, TDD 10-15 mcg/kg, maintenance 3-5 mcg/kg/day divided q12h. For full term neonates, TDD 15-20 mcg/kg, maintenance 5-7 mcg/kg/day. For infants 1-24 months, TDD 20-25 mcg/kg, maintenance 7-10 mcg/kg/day. For children 2-10 years, TDD 10-15 mcg/kg, maintenance 5-7 mcg/kg/day. For children >10 years, TDD 10-15 mcg/kg, maintenance 3-5 mcg/kg/day. Divide TDD into 3-4 doses every 6-8 hours. Maintenance started 12 hours after last loading dose.
Not recommended for children under 12 years. For older children (≥12 years): Pentazocine 50 mg (with naloxone 0.5 mg) orally every 3-4 hours as needed; maximum 6 tablets daily.
Not applicable for pediatric formulation. For elderly, use adult digoxin dosing with caution: reduced renal function may require lower maintenance doses. Typical adult maintenance: 0.0625-0.25 mg daily based on renal function and lean body mass.
Initiate with half the usual adult dose (one-half tablet) and titrate carefully due to increased sensitivity and risk of respiratory depression.
Toxicity can be life-threatening. Use caution in renal impairment, electrolyte disturbances (hypokalemia, hypomagnesemia, hypercalcemia). Narrow therapeutic index requires monitoring.
Risk of respiratory depression, particularly in elderly, cachectic, or debilitated patients; risk of addiction, abuse, and misuse; risk of neonatal opioid withdrawal syndrome with prolonged use during pregnancy; risk of life-threatening respiratory depression when used with benzodiazepines or other CNS depressants.
Monitor serum digoxin levels, renal function, electrolytes (potassium, magnesium, calcium). Risk of arrhythmias (including ventricular fibrillation, bradycardia, AV block). Use with caution in patients with thyroid disease, acute myocardial infarction, or myocarditis.
Respiratory depression; hypotension; increased intracranial pressure; seizure risk (pentazocine); opioid-induced hyperalgesia; adrenal insufficiency; severe hypotension; interaction with MAOIs; risk of dependence and withdrawal; gastrointestinal obstruction; impaired renal or hepatic function; head injury.
Ventricular fibrillation, hypersensitivity to digitalis preparations, hypokalemia (uncorrected), hypercalcemia (uncorrected), AV block (second or third degree) unless pacemaker present.
Hypersensitivity to pentazocine or naloxone; significant respiratory depression; acute or severe bronchial asthma; GI obstruction; known or suspected paralytic ileus; patients receiving MAOIs or within 14 days.
High-fiber foods may decrease absorption; take digoxin 1 hour before or 2 hours after meals. Avoid natural licorice, which can cause hypokalemia and increase toxicity. Maintain consistent dietary potassium intake.
No specific food interactions are reported for this combination. However, grapefruit juice may theoretically affect metabolism via CYP3A4 (pentazocine is metabolized by CYP3A4), but clinical significance is unknown. Advise patients to maintain a consistent diet.
Digoxin crosses the placenta. First trimester: No increased risk of major malformations reported in human studies. Second/third trimester: Potential for fetal toxicity (e.g., bradycardia, cardiac arrhythmias) at maternal toxic doses. No known teratogenicity at therapeutic doses.
Pentazocine crosses the placenta; naloxone has limited placental transfer. No well-controlled human studies. First trimester: Risk cannot be excluded; avoid if possible. Second/Third trimester: Chronic use may cause fetal dependence; neonatal withdrawal syndrome reported. High doses near term may cause neonatal respiratory depression.
Digoxin is excreted into breast milk in low concentrations. M/P ratio approximately 0.6–0.9. Infant dose via milk is <1% of maternal weight-adjusted dose, unlikely to cause adverse effects in term infants. Caution in preterm or neonates with renal impairment.
Pentazocine is excreted in breast milk in small amounts (estimated relative infant dose <3%). Naloxone is poorly bioavailable orally. Generally considered compatible with breastfeeding; monitor infant for sedation or poor feeding. M/P ratio for pentazocine is approximately 1.0.
During pregnancy, increased volume of distribution and renal clearance may reduce serum digoxin levels. Dose adjustments may be required based on therapeutic drug monitoring; typical dose increase of 20–30% in third trimester. Postpartum, reduce dose to prepregnancy level to avoid toxicity.
No established dose adjustments for pregnancy; however, pharmacokinetic changes (increased volume of distribution, enhanced clearance) may require higher or more frequent doses of pentazocine for adequate analgesia. Use lowest effective dose and shortest duration.
Monitor serum digoxin levels (therapeutic range 0.5-2 ng/m L) and renal function, especially in neonates. Correct hypokalemia, hypomagnesemia, and hypercalcemia before administration to reduce toxicity risk. Use with caution in patients with WPW, hypertrophic cardiomyopathy, or incomplete heart block. Dosing in infants and children is based on weight and renal function.
Naloxone in this fixed-dose combination is included to deter opioid abuse by reversing euphoria. The pentazocine component is a mixed agonist-antagonist opioid; naloxone has poor oral bioavailability but becomes active parenterally, precipitating withdrawal in opioid-dependent individuals. Use with caution in patients with impaired renal or hepatic function. Monitor for respiratory depression, especially in opioid-naive patients, as pentazocine alone can cause respiratory depression.
Take exactly as prescribed; do not double up doses.,Monitor for signs of toxicity: nausea, vomiting, vision changes (yellow-green halos), arrhythmias.,Keep medication out of reach of children; immediate medical attention if overdose suspected.,Do not stop abruptly without consulting healthcare provider.,Inform healthcare provider of all medications, including OTC and herbal supplements.
Take exactly as prescribed; do not crush or inject tablets, as injected naloxone can cause severe withdrawal in opioid-dependent individuals.,This medication contains naloxone to discourage misuse; injection will cause withdrawal symptoms.,Report any signs of withdrawal (e.g., nausea, vomiting, sweating, agitation) or breathing difficulty.,Avoid alcohol and other central nervous system depressants as they increase risk of respiratory depression.,Do not use with other opioids unless directed, as effects are unpredictable.,Keep out of reach of children; accidental ingestion may cause severe respiratory depression.
"Eflornithine, an ornithine decarboxylase inhibitor used in the treatment of African trypanosomiasis and hirsutism, may reduce the therapeutic efficacy of digoxin, a cardiotonic glycoside used for heart failure and atrial fibrillation. The proposed mechanism involves eflornithine-induced alterations in gastrointestinal motility or absorption, potentially decreasing digoxin bioavailability. This could lead to subtherapeutic digoxin levels, diminished inotropic and chronotropic effects, and increased risk of arrhythmias or worsening heart failure."
"Osimertinib, a tyrosine kinase inhibitor used in non-small cell lung cancer, can inhibit P-glycoprotein (P-gp) transport in the gastrointestinal tract and kidneys, leading to increased absorption and reduced renal clearance of digoxin. This elevation in serum digoxin concentration heightens the risk of digoxin toxicity, including cardiac arrhythmias (e.g., bradycardia, atrial tachycardia with block) and gastrointestinal symptoms such as nausea and vomiting. Clinical monitoring for digoxin toxicity is warranted, especially when initiating or adjusting osimertinib therapy."
"Lenvatinib, a tyrosine kinase inhibitor, may reduce the therapeutic efficacy of digoxin by interfering with its cardiotonic effects. This interaction could lead to decreased inotropic support in patients with heart failure, potentially worsening cardiac function and clinical outcomes. The clinical consequence is a possible loss of rate control in atrial fibrillation or diminished contractility in systolic dysfunction."
"Cobicistat is a potent CYP3A4 inhibitor used to boost the pharmacokinetics of antiretroviral agents like atazanavir and darunavir. Naloxone primarily undergoes glucuronidation via UGT1A6 and UGT2B7, with minor CYP3A4 metabolism. Concomitant use with Cobicistat may modestly increase naloxone exposure due to CYP3A4 inhibition, but this is unlikely to be clinically significant given naloxone's wide therapeutic index and short half-life."
"Fluvoxamine, a selective serotonin reuptake inhibitor (SSRI), is primarily metabolized by cytochrome P450 (CYP) 1A2 and 2D6. Naloxone, an opioid antagonist, is reported to inhibit CYP1A2, potentially decreasing the clearance of fluvoxamine. This interaction may lead to increased fluvoxamine plasma concentrations, elevating the risk of serotonin syndrome, QT prolongation, and other dose-dependent adverse effects, especially in patients receiving high doses or those with hepatic impairment."
"Naloxone, an opioid receptor antagonist, may inhibit the cytochrome P450 isoenzyme CYP3A4, which is responsible for the metabolism of ivacaftor. Concomitant administration can lead to reduced clearance of ivacaftor, resulting in elevated serum concentrations. This increase may potentiate the therapeutic effects and adverse reactions of ivacaftor, such as hepatotoxicity and QT prolongation."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about DIGOXIN PEDIATRIC vs NALOXONE HYDROCHLORIDE AND PENTAZOCINE HYDROCHLORIDE, answered by our medical review team.
DIGOXIN PEDIATRIC is a Cardiac Glycoside that works by Inhibits sodium-potassium ATPase, increasing intracellular sodium, which promotes calcium influx via sodium-calcium exchanger, enhancing cardiac contractility. Also increases vagal tone, slowing AV conduction.. NALOXONE HYDROCHLORIDE AND PENTAZOCINE HYDROCHLORIDE is a Opioid Agonist-Antagonist that works by Pentazocine is a mixed agonist-antagonist opioid that binds to mu-opioid receptors (partial agonist) and kappa-opioid receptors (agonist), producing analgesia. Naloxone is a pure opioid antagonist that competitively blocks mu, kappa, and delta receptors; when administered orally, naloxone undergoes extensive first-pass metabolism, reducing systemic absorption and primarily blocking the effects of pentazocine if the combination is misused parenterally.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between DIGOXIN PEDIATRIC and NALOXONE HYDROCHLORIDE AND PENTAZOCINE HYDROCHLORIDE depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of DIGOXIN PEDIATRIC is: For pediatric patients, digoxin pediatric dosing is weight-based; no standard adult dose. Typical pediatric loading dose: 10-12 mcg/kg orally divided every 6-8 hours, with maintenance: 5-10 mcg/kg/day divided every 12 hours. For infants <1 month, loading: 10-15 mcg/kg, maintenance: 4-6 mcg/kg/day. For children 1-24 months, loading: 15-20 mcg/kg, maintenance: 5-8 mcg/kg/day. For children >2 years, loading: 10-15 mcg/kg, maintenance: 3-5 mcg/kg/day.. The standard adult dose of NALOXONE HYDROCHLORIDE AND PENTAZOCINE HYDROCHLORIDE is: Oral: One tablet (naloxone 0.5 mg / pentazocine 50 mg) every 3-4 hours as needed for pain; maximum 12 tablets daily.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between DIGOXIN PEDIATRIC and NALOXONE HYDROCHLORIDE AND PENTAZOCINE HYDROCHLORIDE in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. DIGOXIN PEDIATRIC is classified as Category A/B. Digoxin crosses the placenta. First trimester: No increased risk of major malformations reported in human studies. Second/third trimester: Potential for fetal toxicity (e.g., brady. NALOXONE HYDROCHLORIDE AND PENTAZOCINE HYDROCHLORIDE is classified as Category A/B. Pentazocine crosses the placenta; naloxone has limited placental transfer. No well-controlled human studies. First trimester: Risk cannot be excluded; avoid if possible. Second/Thi. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.