Verapamil

IR tablets cover angina (including vasospastic/rest and chronic stable angina), hypertension, ventricular-rate control in chronic atrial flutter/fibrillation in association with digitalis, and repetitive PSVT prophylaxis. The selected ER tablet and PM capsule labels indicate hypertension; do not represent all IR indications as approved for every ER product. Acute chest pain needs clinical assessment rather than self-directed dose escalation.

IV verapamil converts selected PSVT, including some accessory-pathway-associated PSVT, and temporarily controls ventricular rate in atrial flutter/fibrillation except with an accessory bypass tract. Rhythm diagnosis, continuous ECG/BP monitoring, and resuscitation/cardioversion capability are required. It must not be used for ventricular tachycardia or pre-excited AF/flutter.

Individualize; do not exceed 480 mg/day. These are the selected IR label regimens.

Take with food, initially 180 mg each morning; 120 mg/day may be appropriate in sensitive patients. Assess weekly and near 24 hours after the prior dose. Label escalation options: 240 mg each morning; 180 mg morning plus 180 mg evening or 240 mg morning plus 120 mg evening; then 240 mg every 12 hours. The label permits the same total daily milligrams when switching from IR to this tablet under supervision; this is not a rule for every ER system.

Usually 200 mg once daily at bedtime; 100 mg may suit sensitive patients, including older/low-weight or organ-impaired patients. Titrate to 300 mg, then 400 mg at bedtime if needed. Swallow whole or sprinkle the entire contents on one tablespoon of soft, non-hot applesauce, swallow immediately without chewing, and follow with cool water. Do not store the mixture or subdivide pellets.

Give slow IV dosing under continuous ECG and BP monitoring, with emergency support immediately available. Older patients require at least 3 minutes for administration. Infant experience includes rare fatal cardiovascular collapse; the historical label doses are not an endorsement for routine infant use.

Oral labels contraindicate severe LV dysfunction, systolic BP below 90 mm Hg/cardiogenic shock, sick sinus syndrome or second-/third-degree AV block without a functioning pacemaker, and AF/flutter with an accessory bypass tract. IR and ER tablets additionally list known verapamil hypersensitivity; the PM formal section does not list that item. IV contraindications include severe hypotension/shock, the same unpaced nodal blocks, severe CHF unless secondary to a treatable SVT, IV beta blockers in close proximity, pre-excited AF/flutter, ventricular tachycardia, and hypersensitivity.

These selected labels contain no boxed warning. IV rhythm exclusions, hemodynamic collapse risk, and delayed toxicity of ER products remain critical.

Constipation, dizziness, nausea, hypotension, bradycardia, edema, and headache are reported; IV therapy can cause acute severe cardiac effects. Overdose may produce shock, conduction block, arrhythmias, altered mental status, and hyperglycemia. ER toxicity can be delayed; the PM label recommends at least 48 hours of hospital observation after overdose. Emergency management is supportive/toxicologist directed; verapamil is not removed by hemodialysis.

Oral beta blockers, including timolol eye drops, may cause additive bradycardia/AV block or contractility impairment; use only with careful clinical assessment and monitoring. IV beta blockers must not be administered within a few hours of IV verapamil. Avoid ivabradine. Review digoxin concentrations and dose reduction because chronic verapamil can raise its exposure. Clonidine warrants heart-rate monitoring. Do not administer disopyramide within 48 hours before or 24 hours after verapamil; flecainide adds cardiac depression, and quinidine should be avoided in hypertrophic cardiomyopathy.

CYP3A4 inhibitors can raise verapamil levels; inducers such as rifampin or phenobarbital can lower exposure. Grapefruit can raise concentrations and alcohol effects may be prolonged. The verapamil labels cap simvastatin at 10 mg/day but list lovastatin at 40 mg/day; the current lovastatin label instead directs starting at 10 mg and not exceeding 20 mg/day with verapamil. Use that stricter lovastatin instruction and reconcile the actual statin product with the pharmacist. Other CYP3A4 statins may need lower doses. Monitor carbamazepine, cyclosporine, theophylline, and lithium effects/concentrations as appropriate; lithium neurotoxicity can occur despite variable blood levels. Other antihypertensives, anesthetics, and neuromuscular blockers add effects. PM labeling describes interactions with mTOR inhibitors and cancer regimens requiring specialist adjustments.

Pregnancy data are inadequate; labels call for treatment only when clinically justified, and placental transfer occurs. IR/ER tablet and IV labels recommend stopping nursing during use, while PM labeling advises considering infant exposure. LactMed’s August 2025 review reports low milk levels at maternal doses up to 360 mg/day and expects no adverse effects, especially after infant age 2 months, based on limited evidence. Discuss the exact label and maternal/infant needs; this difference is not proof of universal neonatal safety.

Oral safety/effectiveness in children is unestablished in these labels. IV pediatric doses derive from uncontrolled experience, with rare severe/fatal infant reactions. Older adults may be more sensitive and have prolonged exposure; use lower oral starts where appropriate, slower IV administration, and careful monitoring.

Oral renal impairment requires monitoring PR interval and excessive effects, with no universal renal percentage rule. Severe hepatic dysfunction markedly prolongs IR elimination; the oral labels describe approximately 30% of normal dosing with close monitoring, and PM may start at 100 mg. Individualize rather than applying the percentage to an IV bolus. IV significant renal/hepatic failure can prolong duration; repeated injections generally should be avoided, or smaller repeat doses used with close BP/PR monitoring if essential.

L-type calcium-channel inhibition slows AV nodal conduction, reduces myocardial contractility, and dilates peripheral/coronary arteries. This supports rate control, antianginal effects, and lower blood pressure, but also explains heart block, hypotension, and worsening LV dysfunction.

Oral verapamil undergoes extensive first-pass hepatic metabolism; CYP pathways and active norverapamil contribute to interactions and exposure. Most of the dose is eliminated as urinary metabolites, with little unchanged drug. Chronic dosing and hepatic dysfunction prolong elimination. The PM CODAS formulation delays drug release about 4–5 hours after ingestion and peaks roughly 11 hours after dosing, supporting bedtime administration. ER tablet, PM capsule, and IV profiles must not be treated as identical.

For oral treatment, follow BP, pulse, dizziness/syncope, edema/dyspnea, constipation, liver tests, and conduction/PR interval when indicated, especially after dose changes or interacting drugs. Review ventricular function and rhythm before selection. For PM, morning BP reflects near-peak effects and pre-bedtime BP helps assess trough control. IV therapy requires continuous ECG/BP and emergency resuscitation capability.

Take the exact prescribed release system and timing; ER tablets are given with food, whereas the selected PM capsule is taken at bedtime. Follow its applesauce instructions without chewing/dividing pellets. Report fainting, a very slow pulse, worsening breathlessness/swelling, or severe dizziness promptly. Check new prescriptions, OTC medicines, eye-drop beta blockers, grapefruit, alcohol, and anesthesia plans with the clinician. Do not use an extra oral dose to treat an acute rhythm episode.

IR 80-mg tablets: white round scored WATSON 343, 100-tablet bottle NDC 0591-0343-01. Nivagen ER 180-mg tablets: light-blue oval scored C 75, 100-tablet bottle NDC 75834-158-01. Wilshire PM 200-mg capsules: amethyst cap/body, KU/486 200 mg, 100-capsule bottle NDC 52536-486-37. Hospira IV 5 mg/2 mL: 2.5 mg/mL single-dose vial, NDC 0409-1144-65. These identities do not establish current stock.

Covered IR tablets: 40, 80, 120 mg. ER tablets: 120, 180, 240 mg. PM controlled-onset capsules: 100, 200, 300 mg; a 400-mg PM regimen uses two 200-mg capsules. IV: 2.5 mg/mL in labeled 2- or 4-mL single-dose containers. Other once-daily capsule systems, delivery technologies, and trandolapril combinations need separate verification.

IR and ER tablets: 20–25°C; IR in a tight light-resistant child-resistant container, ER protected from light/moisture with label-permitted 15–30°C excursions. PM: 25°C, excursions 15–30°C, protected from moisture in a tight light-resistant container. IV: 20–25°C and protected from light in the package until use; inspect clarity/seal and discard unused single-dose contents immediately after withdrawal. IV admixture compatibility and pH restrictions require the exact injection label and pharmacy review.