Verapamil

Verapamil

Drug monograph · NCLEX study reference
Trade names	Calan
Therapeutic class	Antihypertensive, antianginal, antiarrhythmic
Pharmacologic class	Non-dihydropyridine calcium channel blocker
Onset / peak / duration	PO onset 1 to 2 hours; IV within minutes; ER lasts 24 hours.
Half-life / level	Half-life 3 to 7 hours; no routine level.
Routes	PO (oral), IV
High-alert (ISMP)	IV form warrants extra caution
Black box warning	None
Antidote / reversal	Calcium, atropine, supportive care.
Pregnancy / lactation	Use only if clearly needed.

Nursing pharmacology study reference (NCLEX-style monograph). Numeric values are standard teaching ranges for study and must be verified against current manufacturer labeling before clinical use. This is educational content, not prescribing guidance.

Verapamil (brand name Calan) — Antihypertensive, antianginal, antiarrhythmic; Non-dihydropyridine calcium channel blocker.

Identification

• Therapeutic class: Antihypertensive, antianginal, antiarrhythmic.
• Pharmacologic class: Non-dihydropyridine calcium channel blocker.

Pharmacology

• Mechanism of action: Strongest cardiac-selective calcium blocker; slows AV node conduction and heart rate, with vasodilation.
• Onset / peak / duration: PO onset 1 to 2 hours; IV within minutes; ER lasts 24 hours.
• Half-life / therapeutic level: Half-life 3 to 7 hours; no routine level.

Clinical use

• Indications: Hypertension, angina, supraventricular arrhythmias, rate control.
• Usual dose, route, frequency: 180 to 480 mg PO daily; IV for acute SVT.
• Maximum dose / adjustments: Max about 480 mg/day; reduce in hepatic impairment; pronounced constipation risk in elderly.

Safety

• Contraindications: Severe left ventricular dysfunction, heart block, sick sinus syndrome, hypotension, with IV beta blockers.
• Black box warning: None.
• Interactions: Beta blockers (bradycardia, block), digoxin (raises levels), statins, grapefruit (food).
• Pregnancy / lactation: Use only if clearly needed.
• High-alert: IV form warrants extra caution.

Adverse effects

• Common side effects: Constipation (prominent), bradycardia, edema, dizziness.
• Serious effects to report: Heart block, severe bradycardia, worsening heart failure.
• Antidote / reversal: Calcium, atropine, supportive care.

Nursing process

• Assessment before administration: Heart rate, blood pressure, ECG, bowel pattern.
• Interventions during therapy: Encourage fiber and fluids for constipation; hold for bradycardia.
• Monitor: Heart rate, blood pressure, ECG, bowel function.
• Evaluation / expected outcome: Rate and blood pressure control.

Patient teaching

• Patient teaching: Manage constipation with fiber and fluids.
• Notify provider if: Slow heartbeat, fainting, severe constipation, shortness of breath.
• Administration tips: Swallow ER whole; avoid grapefruit.