COVERA-HS
Clinical safety rating
cautionComprehensive clinical and safety monograph for COVERA-HS (COVERA-HS).
Verapamil hydrochloride is a phenylalkylamine calcium channel blocker that inhibits calcium ion influx across cardiac and smooth muscle cells, thereby reducing afterload and myocardial contractility. In the heart, it slows atrioventricular conduction and prolongs the effective refractory period; in vascular smooth muscle, it causes vasodilation, reducing peripheral vascular resistance.
| Metabolism | Primarily hepatic metabolism via cytochrome P450 enzymes, including CYP3A4, CYP2C8, and CYP1A2, with extensive first-pass effect. Major metabolites include norverapamil (active) and various dealkylated and conjugated metabolites. |
| Excretion | Primarily hepatic metabolism (oxidation and glucuronidation) with renal excretion of inactive metabolites; approximately 80% of metabolites are excreted renally and 15% fecally. |
| Half-life | Terminal elimination half-life is 6–17 hours for immediate-release; for Covera-HS (controlled-onset extended-release), the half-life is 10–20 hours, allowing once-daily bedtime dosing to achieve peak effect in the morning. |
| Protein binding | 95–98% bound to plasma proteins, primarily to albumin. |
| Volume of Distribution | 2.0–2.5 L/kg, indicating extensive tissue distribution. |
| Bioavailability | Oral: 70–86% due to first-pass metabolism. |
| Onset of Action | Capsule: 8–12 hours after bedtime dose (delayed onset designed to deliver maximal antihypertensive effect upon wakening). |
| Duration of Action | Approximately 24 hours with once-daily administration; the controlled-onset formulation maintains therapeutic plasma concentrations throughout the morning surge. |
| Molecular Weight | 454.6 |
180 mg orally once daily at bedtime, extended-release tablet. Maximum dose 540 mg/day.
| Dosage form | TABLET, EXTENDED RELEASE |
| Renal impairment | GFR 30-80 mL/min: no adjustment; GFR <30 mL/min: start at 180 mg daily, titrate cautiously. Not dialyzable. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated. |
| Pediatric use | Safety and efficacy not established; no recommended dosing. |
| Geriatric use | Start at 180 mg orally once daily; titrate slowly due to increased sensitivity and reduced clearance. |
| 1st trimester | Contraindicated. Verapamil is associated with fetal harm; use only if benefit outweighs risk. |
| 2nd trimester | Avoid; verapamil may cause fetal hypoxia and growth restriction. Use only if no safer alternative. |
| 3rd trimester | Avoid near term; may inhibit uterine contractions and cause fetal/neonatal hypotension. |
Clinical note
Comprehensive clinical and safety monograph for COVERA-HS (COVERA-HS).
| Placental transfer | Verapamil crosses the placenta; fetal serum concentrations are about 40-50% of maternal levels. Extensive placental transfer documented. |
| Breastfeeding | Verapamil is excreted into breast milk in low concentrations. Monitor infant for signs of hypotension, bradycardia, or constipation. Consider alternative therapy if infant is premature or has impaired renal function. |
| Lactation Rating | L2 (Probably Compatible) |
| Teratogenic Risk | First trimester: No increased risk of major congenital malformations based on limited human data; animal studies show fetotoxicity at high doses. Second/third trimester: Associated with fetal hypotension, oligohydramnios, intrauterine growth restriction (IUGR), and hypocalcemia. May cause preterm delivery and neonatal renal impairment. |
| Fetal Monitoring | Monitor maternal blood pressure and heart rate, fetal growth and amniotic fluid volume via ultrasound, fetal heart rate monitoring for bradycardia, and neonatal renal function and serum calcium after delivery. |
| Fertility Effects | No known direct adverse effects on female fertility. In males, verapamil may reduce sperm motility and acrosome reaction in vitro, but clinical significance is unclear. |
■ FDA Black Box Warning
None
| Serious Effects |
Severe left ventricular dysfunction (e.g., ejection fraction <30%)Hypotension (systolic BP <90 mmHg)Cardiogenic shockSick sinus syndrome (without pacemaker)Second- or third-degree AV block (without pacemaker)Atrial flutter/fibrillation with accessory bypass tract (e.g., WPW syndrome)Concurrent use of IV beta-blockersHistory of hypersensitivity to verapamil
| Precautions | May cause hypotension, especially in patients with ventricular dysfunction, Can precipitate heart failure or worsen pre-existing heart failure, Risk of bradycardia and heart block, especially in patients with sick sinus syndrome or pre-existing conduction defects, Caution in patients with hypertrophic cardiomyopathy due to risk of worsening obstruction and hypotension, Avoid abrupt withdrawal in patients with angina; may cause severe exacerbation, May increase serum levels of digoxin, cyclosporine, and other CYP3A4 substrates, Use with caution in patients with hepatic impairment due to reduced clearance, May cause symptomatic hypotension when administered with beta-blockers or other antihypertensives, Monitor for constipation, especially in elderly patients |
| Food/Dietary | Avoid grapefruit and grapefruit juice; may increase verapamil serum concentrations. Limit alcohol intake; can potentiate hypotensive effects and increase risk of bradycardia. High-fat meals may delay absorption but do not significantly alter AUC; take consistently with food. |
| Clinical Pearls | Covera-HS (verapamil extended-release) is formulated for bedtime dosing to maximize blood pressure control during early morning surge. Avoid use in patients with pre-excited atrial fibrillation (Wolff-Parkinson-White syndrome) due to risk of ventricular fibrillation. Monitor for constipation, especially in elderly. Adjust dose in hepatic impairment; contraindicated in severe left ventricular dysfunction and hypotension. |
| Patient Advice | Take exactly as prescribed, usually once daily at bedtime, with food to minimize gastrointestinal irritation. · Swallow tablet whole; do not crush, chew, or break. · Do not discontinue abruptly; may cause rebound hypertension or angina. · Avoid grapefruit juice and alcohol; they can increase verapamil levels or enhance side effects. · Report symptoms such as slow heartbeat, dizziness, fainting, or swelling of ankles/feet. |
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