Logo

OpiCalc

FavoritesSpecialtiesDrugsGuidelinesMost Used

Quick Access

Favorites
Most Used

All Specialties

OpiCalc Logo
Clinical CalculatorsDrugsGuidelines
SpecsDrugsGuides
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
OpiCalc Logo

OpiCalc

Easy, fast, and private medical tools for clinicians. Always free.

No Login Required
Ready for the Bedside

Resources

About UsEditorial PolicyMedical DisclaimerPrivacy PolicyTerms of UseCookie Policy

Support

Contact Us

Clinical Notice:OpiCalc is not a substitute for professional clinical judgment. Always verify dosages and guidelines.

OpiCalc © 2018-2026

•

All Rights Reserved

Registry Hub
Antihypertensive (Centrally Acting Adrenergic Blocking Agent)/Discontinued

MODERIL

MODERIL

Clinical safety rating

caution

Comprehensive clinical and safety monograph for MODERIL (MODERIL).


Mechanism of Action

Reserpine is an alkaloid that depletes catecholamines (norepinephrine, dopamine) and serotonin from central and peripheral nerve endings by irreversibly binding to and inhibiting the vesicular monoamine transporter (VMAT), preventing storage and leading to degradation by monoamine oxidase.

What the body does with it

MetabolismExtensively metabolized in the liver via hydrolysis and conjugation; cytochrome P450 (CYP) enzymes not majorly involved.
ExcretionRenal: 60% (mainly as unchanged drug); biliary/fecal: ~40% (includes glucuronide conjugates).
Half-lifeTerminal elimination half-life: 2.5–3.5 hours; may be prolonged to 6–8 hours in severe renal impairment.
Protein binding50–70% bound to albumin and α1-acid glycoprotein.
Volume of DistributionVd: 2–4 L/kg, indicating extensive tissue distribution.
BioavailabilityOral: 50–70% (first-pass effect); IM: 100%; IV: 100%.
Onset of ActionIM: 15–30 minutes; IV: 5–10 minutes; oral: 30–60 minutes.
Duration of ActionIM/IV: 1–2 hours; oral: 4–6 hours; antihypertensive effect persists 6–12 hours with controlled-release formulation.
Molecular Weight608.68

Classification & Brands

Dosing & administration

1-10 mg orally twice daily, titrate to effect.

Dosage formTABLET
Renal impairmentGFR <30 mL/min: reduce dose by 50%; GFR <15 mL/min: not recommended.
Liver impairmentChild-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated.
Pediatric use0.1-0.5 mg/kg/day divided every 12 hours, max 10 mg/day.
Geriatric useInitiate at 1 mg once daily, titrate slowly; monitor for hypotension and sedation.

Use during pregnancy

1st trimesterReserpine is contraindicated in first trimester due to risk of fetal malformations including skeletal abnormalities and CNS defects; use only if no alternative.
2nd trimesterUse with caution; may cause maternal hypotension leading to reduced placental perfusion, respiratory depression, and bradycardia in fetus.
3rd trimesterAvoid near term because reserpine may cause severe neonatal adverse effects such as nasal congestion, respiratory depression, bradycardia, and hypothermia.

Clinical note

Comprehensive clinical and safety monograph for MODERIL (MODERIL).

Placental transferReserpine crosses the placenta, with fetal concentrations up to 50% of maternal levels; CNS effects observed in animal studies.
BreastfeedingReserpine is excreted into breast milk; may cause infant diarrhea, nasal congestion, and lethargy. Avoid breastfeeding during therapy.
Lactation RatingL5
Teratogenic RiskCategory C. First trimester: insufficient data; animal studies show embryotoxicity at high doses. Second/third trimesters: risk of fetal hypotension and renal impairment due to maternal hypotension; may reduce uteroplacental perfusion.
Fetal MonitoringMaternal: blood pressure (sitting and standing) q1-2h initially, heart rate, signs of hypotension/syncope. Fetal: serial ultrasound for growth restriction (if used in 2nd/3rd trimesters), nonstress test or biophysical profile if preeclampsia risk; monitor for fetal bradycardia after maternal dosing.
Fertility EffectsNo formal studies; animal data show no impairment of fertility at therapeutic doses. Postulated: alpha-1 blockade may affect ejaculatory function in males, but no evidence of altered spermatogenesis or impact on female fertility.

Warnings & precautions

■ FDA Black Box Warning

None.

Side Effect Profile

Serious Effects

Absolute Contraindications

Hypersensitivity to reserpine or any componentHistory of mental depression, especially with suicidal tendenciesActive peptic ulcerUlcerative colitisElectroconvulsive therapy (within 2 weeks)Concomitant use with MAO inhibitors

Clinical Precautions

PrecautionsMental depression, especially in patients with history of depression, Peptic ulcer disease exacerbation, Electroconvulsive therapy (ECT) use caution due to severe reactions, Biliary colic in patients with gallstones, Surgery: increased susceptibility to hypotension and bradycardia
Food/DietaryAvoid tyramine-rich foods (aged cheeses, cured meats, fermented products) to prevent hypertensive crises.

Clinical Tips & Counseling

Clinical PearlsModeril (reserpine) is an antihypertensive alkaloid. Onset is slow (3-6 days) and duration prolonged (1-6 weeks). Use with caution in patients with history of depression or peptic ulcer. Monitor for bradycardia and orthostatic hypotension. Discontinue at least 2 weeks before elective surgery to reduce risk of hypotension with anesthetics.
Patient AdviceTake exactly as prescribed; do not stop suddenly due to risk of severe hypertension. · May cause drowsiness, dizziness, or nasal congestion; avoid driving if affected. · Rise slowly from sitting or lying to prevent fainting. · Report any signs of depression, mood changes, or nightmares to your doctor. · Avoid alcohol and other CNS depressants. · Inform all healthcare providers you are taking this medication.

MODERIL Interactions

Loading safety data…

This overview is compiled from peer-reviewed clinical sources and FDA labeling. It's here to support — not replace — clinical judgment. Always verify dosing against your institution's current protocols before prescribing.

On this page

Mechanism of ActionDosing & administrationUse during pregnancyWarnings & precautionsDrug interactions

External sources

DailyMed (NIH) PubMed OpenFDA