Verapamil ER
CALAN SR
Pronunciation: ver-AP-a-mil
What it isL-type calcium-channel blocker that slows AV conduction and relaxes arteries; hypertension, angina, and supraventricular arrhythmias.
Why this oneIts strong AV-nodal effect provides rate control that dihydropyridine calcium-channel blockers cannot.
What limits itConstipation, bradycardia, and heart block limit use; avoid systolic heart failure and watch CYP3A4 and P-gp interactions.
FDA label
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| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Hypertension | Adults | 180 mg once daily in the morning (120 mg if elderly/small) | Titrate to 240 mg QD, then 360 mg/day, then 480 mg/day | 480 mg/day |
Titration Upward titration based on efficacy/safety evaluated weekly (and ~24 h after previous dose).
Renal Administer cautiously; ~70% excreted in urine, not removed by hemodialysis; monitor for PR prolongation/overdosage.
Hepatic Severe liver dysfunction: administer ~30% of the normal dose; monitor.
Instructions
- Administer with food
- Take in the morning
- Same total daily dose when switching from immediate-release verapamil
Available strengths
- ER tab 120, 180, 240 mg
- tab 40, 80, 120 mg
- DR cap 120, 180, 240, 360 mg
- ER cap 100, 120, 180, 200, 240, 300, 360 mg
- inj 2.5 mg/mL
Contraindications
- Severe left ventricular dysfunction
- Hypotension (systolic <90 mm Hg) or cardiogenic shock
- Sick sinus syndrome (except with a functioning pacemaker)
- Second- or third-degree AV block (except with a functioning pacemaker)
- Atrial flutter/fibrillation with an accessory bypass tract (e.g., WPW, Lown-Ganong-Levine)
Cautions
- Heart failure/pulmonary edema
- Hypotension
- Elevated liver enzymes
- AV block/bradycardia
- Increased digoxin levels
- Caution in attenuated neuromuscular transmission
Adverse reactions
- Constipation
- Dizziness
- Nausea
- Hypotension
- Headache
- Edema
- Bradycardia
- AV block
Pregnancy No evidence of teratogenicity in animals; use only if clearly needed (crosses placenta).
Lactation Undefined.
Cost
| Strength | #/mo | generic $/mo | CostPlus | |
|---|---|---|---|---|
| 120 mg | ER tab | 30 qd | $5.33 | offered |
| 180 mg | ER tab | 30 qd | $5.73 | offered |
| 240 mg | ER tab | 30 qd | $5.28 | offered |
Other forms: Verapamil (CALAN)
NO BOXED WARNINGS
Principal riskHeart failure, hypotension and AV block