THE INDIAN PHARMACIST Official Circular Pharmacy Logo THE INDIAN PHARMACISTLearn. Explore. Practise. Excel.
MEDICINE MONOGRAPH CODE: [3.35] ID: TIP-MED-000035

Methyldopa

Active Ingredient / Scientific Identity: Methyldopa • Class: Centrally Acting Alpha-2 Adrenoceptor Agonist Prodrug (Schedule H | NLEM 2022)

⚖️ Compare Profile
THE INDIAN PHARMACIST — Educational Reference Sheet
Profile: Methyldopa ([3.35] | ID: TIP-MED-000035) • Last Reviewed: 2026-11-10
Source URL: https://theindianpharmacist.com/medicine/3-35-methyldopa/
Generic / Entity NameMethyldopa ([3.35])
Verified Indian Brands / RefGeneric Compendial Entry (No Commercial Brand Claimed)
Pharmacological ClassCentrally Acting Alpha-2 Adrenoceptor Agonist Prodrug (Schedule H | NLEM 2022)
Available Dosage FormsTablets: 250 mg, 500 mg
Regulatory ClassificationSchedule H Prescription Drug (To be sold by retail on the prescription of a Registere
Key Warning & Review DateRenal: Active metabolites accumulate in CKD — extend dosing interval to q8–12h if eGFR <50 mL/min. Hepatic: Contraindicated i
Reviewed: 2026-11-10
Safety Matrix:⚖️ Legal Status: Schedule H Prescription Drug (To be sold by retail o✔️ Standard Clinical Dispensing Precautions

1. Clinical & Scientific Overview

Methyldopa (TIP-MED-000035, Reference Code [3.35]) is classified under Cardiovascular & Antithrombotic Medicines (Ch 03) as a Centrally Acting Alpha-2 Adrenoceptor Agonist Prodrug (Schedule H | NLEM 2022). Within the Indian regulatory and compendial framework, it is governed under Schedule H Prescription Drug (To be sold by retail on the prescription of a Registered Medical Practitioner only — Drugs Rules 1945).

Verified Indian Market Examples / Compendial Status:
Representative Indian Market Examples (Edition 2.7 Ch 03 [3.35], p. 38): Alphadopa (Wockhardt), Aldomet, Emdopa (East India) — Strengths & Dosage Forms: Tablets: 250 mg, 500 mg
Representative Indian Market Examples (Edition 2.7 Ch 03 [3.35], p. 38): Alphadopa (Wockhardt), Aldomet, Emdopa (East India) — Strengths & Dosage Forms: Tablets: 250 mg, 500 mg
Dosage Forms & Available Strengths:
Tablets: 250 mg, 500 mg
Routes: Oral / Parenteral / Topical as specified by formulation

3. Mechanism of Action & Pharmacodynamics

Centrally Acting Alpha-2 Adrenoceptor Agonist Prodrug (Schedule H | NLEM 2022) acting on target receptor/enzyme pathways in Cardiovascular & Antithrombotic Medicines (Ch 03): clinical efficacy is mediated via Centrally Acting Alpha-2 Adrenoceptor Agonist Prodrug (Schedule H | NLEM 2022) for Gestational hypertension and chronic hypertension in pregnancy (long-term foetal safety record alongside Labetalol and Nifedipine SR).

4. Therapeutic Indications & Evidence-Supported Uses

  • Gestational hypertension and chronic hypertension in pregnancy (long-term foetal safety record alongside Labetalol and Nifedipine SR)

🇮🇳 Jurisdiction & Indication Note: Indications and schedules reflect Indian compendial and regulatory records (CDSCO / Indian Pharmacopoeia & NFI / NLEM 2022). Where international reference labels (US FDA DailyMed / NCBI StatPearls) are cited for pharmacokinetic or mechanistic parameters, international approvals do not automatically imply CDSCO approval in India.

5. Educational Dosage Context, Formulations & Administration

Educational Dosing & Regimen Summary: Start 250 mg PO BD–TDS; titrate every 2–3 days to 250–500 mg TDS (Max 2000–3000 mg/day)

Administration & Meal Timing: May be taken with or without food | Morning, Afternoon & Night (TDS) or Morning & Evening (BD)

6. Pharmacokinetics, Metabolism & Renal/Hepatic Adjustment

Absorption & Disposition:
Absorption, distribution, metabolism, and excretion follow class pharmacokinetic profile; verify patient renal/hepatic function.
Metabolism & Biotransformation:
Renal: Active metabolites accumulate in CKD — extend dosing interval to q8–12h if eGFR <50 mL/min. Hepatic: Contraindicated in active liver disease
Elimination & Renal Adjustment:
Renal: Active metabolites accumulate in CKD — extend dosing interval to q8–12h if eGFR <50 mL/min. Hepatic: Contraindicated in active liver disease
Hepatic Impairment Considerations:
Renal: Active metabolites accumulate in CKD — extend dosing interval to q8–12h if eGFR <50 mL/min. Hepatic: Contraindicated in active liver disease

7. Contraindications, Precautions & High-Risk Warnings

Contraindications & Red-Flag Precautions:
  • Contraindicated in active hepatic disease (acute hepatitis, cirrhosis), history of Methyldopa-induced haemolytic anaemia, and clinical depression (especially postpartum)

Key Clinical Precautions: Renal: Active metabolites accumulate in CKD — extend dosing interval to q8–12h if eGFR <50 mL/min. Hepatic: Contraindicated in active liver disease

8. Adverse Effects Profile

Common & Mechanism-Related Adverse Effects:
  • Sedation/drowsiness (especially during first 1–2 weeks), dry mouth, headache, nasal stuffiness, postural dizziness, positive direct Coombs test (10–20%)
  • Autoimmune Coombs-positive haemolytic anaemia (rare <1%), drug-induced hepatitis/hepatic necrosis (most common in first 2–3 months), postpartum depression
Serious / Dose-Limiting Adverse Effects:
  • Monitor for severe hypersensitivity, organ toxicity, or dose-limiting adverse events.

9. Major Drug–Drug, Drug–Food & Drug–Herb Interactions

  • Oral Iron (Ferrous Sulfate/Ascorbate) chelates Methyldopa in the gut, reducing Methyldopa absorption by up to 50–70% and worsening BP control — separate Methyldopa and Iron by >=2–3 hours! Increases Lithium toxicity

10. Clinical Monitoring, Patient Counselling & Storage

Clinical & Laboratory Monitoring: Monitor clinical response, baseline renal/hepatic parameters, and relevant serum biomarkers.

Pharmacist Patient Counselling Points:

  • Patient Counselling Checklist: Space at least 2–3 hours apart from your pregnancy Iron tablets (Iron blocks Alphadopa absorption!); drowsiness usually improves after 1 week; switch medicine after delivery to avoid baby-blues depression
  • Meal & Clock Timing Instruction: May be taken with or without food (Morning, Afternoon & Night (TDS) or Morning & Evening (BD))
  • Missed Dose Protocol: Take as soon as remembered unless within 4h of next dose; do not double dose
  • Geriatric Dispensing Pearl: Avoid in older adults (AGS Beers 2023: high rates of bradycardia, sedation, depression, and orthostasis)

Storage, Stability & Dispensing Safeguards: Store below 25°C–30°C in original moisture- and light-resistant packaging out of reach of children. Available forms: Tablets: 250 mg, 500 mg

11. Visual Pharmacology & Mechanism Diagram (svg-v339-01-adme-12-step-journey)

THE 12-STEP ORAL DRUG JOURNEY THROUGH THE HUMAN BODY (LADME) Note: IV bolus enters Step 6 directly (F = 100%); Sublingual & Transdermal routes bypass Step 4–5 Portal First-Pass Metabolism 1. Oral Administration • Tablet / Capsule swallowed • Gastric emptying to duodenum pH 1.5–3.5 (Stomach) 2. Disintegration & Dissolution • Tablet breaks into granules • API dissolves in GI fluid Noyes-Whitney Dissolution Rate 3. GI Epithelial Absorption • Crosses intestinal villi • Passive / Active / P-gp efflux Small Intestine (Large Surface Area) 4. Portal Circulation • Mesenteric veins → Portal vein • Delivers blood to liver sinusoids Pre-systemic Venous Conduit 5. First-Pass Metabolism • Gut & hepatic CYP450 extraction • High: GTN, Propranolol, Morphine Determines Bioavailability (F = f_a × (1-E_H)) 6. Systemic Circulation • Hepatic vein → IVC → Heart • Unbound vs Albumin-bound drug Only FREE drug is active 7–8. Tissue Distribution (Vd) • Capillary permeation to organs • Blood-Brain & Placental barriers Vd = Dose / C_0 (L or L/kg) 9. Target Site of Action • Receptors (GPCR, Ion channel) • Enzymes & Carrier Transporters Pharmacodynamic Effect (E_max, EC50) 10. Hepatic Biotransformation • Phase I (CYP450 Oxidation/Hydrolysis) • Phase II (Glucuronidation/Sulfation) Converts lipophilic drug → hydrophilic metabolite 11. Renal & Biliary Elimination • Nephron: Filtration + Secretion − Reabsorption • Biliary excretion & Enterohepatic recycling Total Clearance CL_tot = CL_renal + CL_hepatic 12. Excretion from the Body • Urine (Primary polar metabolite route) • Bile/Faeces, Expired Air, Sweat, Milk Elimination Half-Life t1/2 = (0.693 × Vd) / CL
svg-v339-01-adme-12-step-journey — 8.1 Complete 12-Step Journey of an Orally Administered Drug (ADME): Figure 8.1: The 12-step physiological journey of a typical orally administered solid dosage form through Liberation, Absorption, Distribution, Metabolism, and Excretion (LADME). Note: Parenteral (IV), sublingual, and inhalational routes bypass gastrointestinal absorption and/or hepatic first-pass metabolism.

12. Authoritative References, Regulatory Sources & Editorial Disclaimer

Primary Compendial & Guideline Reference: Indian Pharmacist Desk Reference — Professional Edition 2.7 (2026–27) • Ch 03 [3.35] (p. 38)

Official Verification Portals: Indian Pharmacopoeia Commission (IPC) & National Formulary of India (NFI) • Central Drugs Standard Control Organization (CDSCO) • Ministry of Health & Family Welfare — NLEM 2022 • NCBI Bookshelf / StatPearls Pharmacology Reference • DailyMed (US FDA Official Prescribing Reference)

Last Medically & Pharmaceutically Reviewed: 2026-11-10 • Verification Status: HANDBOOK_SOURCE_CONTENT

Educational & Clinical Disclaimer: This reference profile is published solely for pharmacy education, academic study, and professional clinical reference. It does not substitute for patient-specific clinical judgement, qualified specialist oncology/medical supervision, or official CDSCO/IP prescribing information. Never self-medicate with prescription, Schedule H/H1/X, NDPS, or oncology medicines.

← Back to All 644 Reference Profiles 📖 Explore 40 Knowledge Hub Articles → ✉️ Report Errata / Feedback
Educational Reference Notice: This printout from THE INDIAN PHARMACIST (https://theindianpharmacist.com/medicine/3-35-methyldopa/, Last Reviewed: 2026-11-10) is an educational reference sheet for students and healthcare learners. It is NOT an official prescribing guideline or patient-specific treatment order.