QUINORA
Clinical safety rating
cautionComprehensive clinical and safety monograph for QUINORA (QUINORA).
Quinora (quinidine) is a Class Ia antiarrhythmic agent that blocks sodium channels, prolonging the action potential duration and effective refractory period. It also exhibits anticholinergic and negative inotropic effects.
| Metabolism | Primarily hepatic via CYP3A4; also metabolized by CYP2C9 and CYP2E1. Active metabolites include 3-hydroxyquinidine. Renal excretion of unchanged drug accounts for 10-20% of clearance. |
| Excretion | Primarily hepatic (biliary) excretion into feces (~80-90%); renal excretion of unchanged drug accounts for ~10-20%. |
| Half-life | 5-7 hours; prolonged in hepatic impairment (up to 12-15 hours) and in elderly patients. |
| Protein binding | 90-95% bound to plasma proteins (primarily albumin and alpha-1-acid glycoprotein). |
| Volume of Distribution | 2.5-3.5 L/kg; extensive tissue distribution with high affinity for cardiac muscle. |
| Bioavailability | Oral: ~70-80% (first-pass metabolism reduces bioavailability; food may decrease rate but not extent). |
| Onset of Action | Oral: 30-60 minutes; IV: within 5 minutes. |
| Duration of Action | 6-8 hours after single dose; may extend with repeated dosing due to accumulation. |
| Molecular Weight | 198.2 |
325 mg orally every 4 to 6 hours as needed, not to exceed 4 g/day.
| Dosage form | TABLET |
| Renal impairment | GFR 30-50 mL/min: reduce dose by 25%; GFR <30 mL/min: avoid use or prolong dosing interval to every 8 hours. |
| Liver impairment | Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50%; Child-Pugh Class C: avoid use. |
| Pediatric use | 10-15 mg/kg/dose orally every 4-6 hours; maximum 60 mg/kg/day. |
| Geriatric use | Start at lowest effective dose; consider 325 mg every 6-8 hours due to increased risk of accumulation. |
| 1st trimester | Contraindicated due to risk of fetal harm; may cause fetal malformations. |
| 2nd trimester | Contraindicated; use alternatives. |
| 3rd trimester | Contraindicated; may cause neonatal toxicity. |
Clinical note
Comprehensive clinical and safety monograph for QUINORA (QUINORA).
| Placental transfer | Crosses placenta; fetal serum concentrations may approach maternal levels. |
| Breastfeeding | Excreted into breast milk; may cause adverse effects in nursing infants. Discontinue breastfeeding or discontinue drug, considering importance to mother. |
| Lactation Rating | L4 - Possibly Hazardous |
| Teratogenic Risk | In first trimester, associated with increased risk of spontaneous abortion and congenital anomalies including cardiovascular and neural tube defects. Second and third trimester exposure may cause premature closure of ductus arteriosus, oligohydramnios, and neonatal renal impairment. |
| Fetal Monitoring | Monitor maternal CBC, hepatic function, renal function, and serum drug levels. Fetal monitoring includes ultrasound for fetal growth, amniotic fluid volume, and ductus arteriosus patency after 28 weeks gestation. |
| Fertility Effects | May cause reversible inhibition of spermatogenesis and ovulation. No evidence of permanent fertility impairment. |
■ FDA Black Box Warning
May cause potentially fatal ventricular arrhythmias (e.g., torsades de pointes) due to QT prolongation. Reserve for patients with life-threatening arrhythmias. Monitor ECG and serum electrolytes. Discontinue if QT interval >50% baseline or QRS duration increases >25%.
| Serious Effects |
Known hypersensitivity to quinora or any componentGlucose-6-phosphate dehydrogenase (G6PD) deficiencyPregnancy
| Precautions | May cause cinchonism (tinnitus, headache, visual disturbances). Risk of QT prolongation and torsades de pointes, especially in patients with hypokalemia, bradycardia, or structural heart disease. Hemolytic anemia may occur in G6PD deficiency. Can exacerbate heart failure due to negative inotropic effects. Drug interactions: hepatic enzyme inducers/inhibitors, other QT-prolonging drugs. |
| Food/Dietary | Grapefruit juice increases quinidine levels; avoid concurrent use. Food does not affect absorption significantly; take with or without food. High-fat meals may delay absorption. |
| Clinical Pearls | Quinora (quinidine) is a class Ia antiarrhythmic; monitor for QT prolongation and torsades de pointes. Use with caution in heart failure, renal impairment, and hepatic dysfunction. Check serum potassium and magnesium levels before initiation. Watch for cinchonism (tinnitus, headache, blurred vision) at high doses. Avoid use with other QT-prolonging drugs. Therapeutic drug monitoring is recommended (target 2-6 mcg/mL). |
| Patient Advice | Take exactly as prescribed; do not skip doses or double up if missed. · Report any signs of allergic reaction (rash, fever, difficulty breathing) or unusual bleeding/bruising. · Avoid grapefruit juice as it may increase quinidine levels. · Contact your doctor if you experience dizziness, fainting, or palpitations. · Do not stop abruptly; taper as directed to avoid rebound arrhythmias. · Tell all healthcare providers you are taking quinidine. |
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