Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
COVERA-HS vs ACTAHIST
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
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.
Antihistamine; binds to histamine H1 receptors, blocking the effects of histamine; also exhibits anticholinergic and mild sedative properties.
Hypertension,Angina pectoris including chronic stable angina, vasospastic (Prinzmetal's) angina, and unstable angina,Supraventricular tachyarrhythmias including atrial fibrillation/flutter and paroxysmal supraventricular tachycardia
Symptomatic relief of allergic rhinitis,Urticaria,Off-label: motion sickness,Off-label: insomnia
180 mg orally once daily at bedtime, extended-release tablet. Maximum dose 540 mg/day.
1.34 mg (one capsule) orally twice daily.
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.
6.9 ± 1.7 hours in adults; prolonged to 12-18 hours in elderly or patients with hepatic impairment, requiring dosing interval adjustment.
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.
Hepatic metabolism via CYP450 enzymes (primarily CYP3A4 and CYP2D6); major metabolite is inactive.
Primarily hepatic metabolism (oxidation and glucuronidation) with renal excretion of inactive metabolites; approximately 80% of metabolites are excreted renally and 15% fecally.
Primarily renal (approximately 85% as unchanged drug and metabolites) and fecal (15%) via biliary elimination.
95–98% bound to plasma proteins, primarily to albumin.
92% bound to albumin.
2.0–2.5 L/kg, indicating extensive tissue distribution.
0.9 ± 0.3 L/kg, indicating extensive extravascular distribution.
Oral: 70–86% due to first-pass metabolism.
Oral: 68% ± 12% due to first-pass metabolism.
GFR 30-80 m L/min: no adjustment; GFR <30 m L/min: start at 180 mg daily, titrate cautiously. Not dialyzable.
No dose adjustment required for mild to moderate renal impairment. Safety not established for severe impairment (GFR <30 m L/min).
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated.
No dose adjustment required for mild to moderate hepatic impairment (Child-Pugh A or B). Not recommended for severe hepatic impairment (Child-Pugh C).
Safety and efficacy not established; no recommended dosing.
Not indicated for pediatric patients under 12 years of age. Safety and efficacy not established.
Start at 180 mg orally once daily; titrate slowly due to increased sensitivity and reduced clearance.
No specific dose adjustment recommended; monitor for increased anticholinergic effects and cognitive impairment.
None
None.
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
May cause drowsiness; caution when driving or operating machinery. Avoid alcohol. Use with caution in patients with narrow-angle glaucoma, prostatic hyperplasia, or urinary retention. Geriatric patients more sensitive to anticholinergic effects. Pediatric patients <6 years: not recommended.
Severe left ventricular dysfunction (ejection fraction <30%),Hypotension (systolic blood pressure <90 mm Hg),Cardiogenic shock,Sick sinus syndrome (unless pacemaker in place),Second- or third-degree AV block (unless pacemaker in place),Atrial fibrillation/flutter with accessory bypass tract (e.g., Wolff-Parkinson-White syndrome),Known hypersensitivity to verapamil or any component of the formulation,Concurrent use of ivabradine
Hypersensitivity to any component. Newborns or premature infants. Breastfeeding (contraindicated due to risk of adverse effects in infants). Concomitant use with MAOIs.
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.
Avoid high-tyramine foods (aged cheese, cured meats, fermented products) if taking MAOIs. Grapefruit juice may increase phenylephrine absorption; limit intake.
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.
ACTAHIST (brompheniramine/phenylephrine) pregnancy category C. Inadequate human data; animal studies show no malformations at therapeutic doses. First trimester: theoretical risk from vasoconstrictive effects (phenylephrine) possibly reducing uterine blood flow; avoid if possible. Second/third trimester: phenylephrine may cause fetal hypoxia via placental vasoconstriction; use only if benefit outweighs risk. No known structural teratogenicity.
Verapamil (active ingredient) is excreted into human breast milk at low concentrations (M/P ratio ~0.6-0.8). Estimated infant dose is <0.1% of maternal weight-adjusted dose. Considered compatible with breastfeeding, but monitor infant for hypotonia, bradycardia, and constipation.
Brompheniramine is excreted in breast milk in small amounts; M/P ratio not established. Phenylephrine has minimal excretion. Due to anticholinergic effects, may reduce milk production or cause sedation in infants. Use caution; prefer non-sedating alternatives if possible.
No specific dose adjustments are routinely recommended; however, pharmacokinetic changes in pregnancy (increased plasma volume, increased renal clearance) may necessitate dose titration based on clinical response. Consider using lowest effective dose to minimize fetal hypotension and hypoperfusion.
No specific pharmacokinetic studies. Increased plasma volume and renal clearance in pregnancy may reduce drug levels, but efficacy threshold remains. No dose adjustment recommended; use the lowest effective dose for shortest duration due to potential risks.
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.
Actahist is a combination antihistamine-decongestant (chlorpheniramine/phenylephrine). Avoid in patients with hypertension, severe coronary artery disease, or MAOI use. Monitor for sedation and urinary retention, especially in elderly males with BPH.
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.
Take with food or milk to reduce stomach upset.,Avoid alcohol and CNS depressants as they can increase drowsiness.,Do not drive or operate machinery until you know how this medication affects you.,Contact your doctor if you experience chest pain, rapid heartbeat, or difficulty urinating.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about COVERA-HS vs ACTAHIST, answered by our medical review team.
COVERA-HS is a Calcium Channel Blocker that works by 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.. ACTAHIST is a Antihistamine that works by Antihistamine; binds to histamine H1 receptors, blocking the effects of histamine; also exhibits anticholinergic and mild sedative properties.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between COVERA-HS and ACTAHIST depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of COVERA-HS is: 180 mg orally once daily at bedtime, extended-release tablet. Maximum dose 540 mg/day.. The standard adult dose of ACTAHIST is: 1.34 mg (one capsule) orally twice daily.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between COVERA-HS and ACTAHIST in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. COVERA-HS is classified as Category C. 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. ACTAHIST is classified as Category C. ACTAHIST (brompheniramine/phenylephrine) pregnancy category C. Inadequate human data; animal studies show no malformations at therapeutic doses. First trimester: theoretical risk f. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.