Drug Class: Centrally Acting Alpha-2 Adrenergic Agonist / Antihypertensive | Form: Oral Tablet | Prescription Status: Prescription Only (Rx) — DRAP Registered
What is Aldomet 250mg Tablet? Aldomet 250mg contains Methyldopa — one of the oldest and most extensively studied antihypertensive medicines with a uniquely important role in pregnancy-related hypertension management. Unlike most modern antihypertensives that are contraindicated in pregnancy, Methyldopa has a decades-long safety record in pregnant women with no evidence of foetal harm — making it the first-choice antihypertensive for gestational hypertension, pre-eclampsia, and chronic hypertension in pregnancy in international obstetric guidelines. It works centrally in the brain — reducing sympathetic nervous system outflow to blood vessels rather than acting directly on peripheral vessels. While its sedative side effects and twice to three times daily dosing make it less convenient than newer antihypertensives for non-pregnant patients, its unmatched pregnancy safety profile makes Aldomet 250mg an irreplaceable medicine in obstetric practice.
What is Aldomet 250mg Used For?
- Hypertension in pregnancy — gestational hypertension and pre-eclampsia (حمل میں ہائی بلڈ پریشر — سب سے محفوظ انتخاب)
- Chronic hypertension during pregnancy — managing pre-existing high blood pressure throughout pregnancy
- Essential hypertension — general blood pressure management in non-pregnant adults
- Hypertensive crisis — acute severe blood pressure elevation requiring controlled reduction
- Renal hypertension — high blood pressure associated with kidney disease
- Hypertension in breastfeeding women — considered compatible with breastfeeding under medical supervision
How Does it Work? Methyldopa is converted in the central nervous system to alpha-methylnorepinephrine — a potent alpha-2 adrenergic agonist that stimulates inhibitory alpha-2 receptors in the brainstem. Stimulating these receptors reduces sympathetic nervous system outflow from the brain to peripheral blood vessels and the heart — decreasing vascular resistance, lowering heart rate, and reducing blood pressure through central rather than peripheral action. This centrally mediated mechanism is fundamentally different from peripheral antihypertensives — making Methyldopa effective even in patients who have not responded to other blood pressure medicines and explaining its favourable safety profile in pregnancy where peripheral vasoactive medicines carry greater foetal risk.
Dosage and Administration
⚠️ Never stop suddenly after long-term use — rebound hypertension can occur. Blood pressure response develops gradually over 24 to 48 hours after dose changes. Monitor liver function and blood count periodically during long-term use. Take at consistent times daily. Causes significant sedation — avoid driving particularly when starting or adjusting dose.
| Indication | Usual Adult Dose | Frequency | Notes |
|---|---|---|---|
| Hypertension — initial | 250mg | Two to three times daily | Increase gradually if needed |
| Hypertension — maintenance | 250 – 500mg | Two to three times daily | Maximum 3g daily |
| Pregnancy hypertension | 250mg | Two to three times daily | First-line choice — adjust under obstetrician supervision |
| Elderly patients | 125 – 250mg | Twice daily initially | Very cautious titration — high sedation risk |
Active Ingredients
| Ingredient | Strength |
|---|---|
| Methyldopa | 250mg |
Who Should NOT Take Aldomet 250mg?
- Allergy to Methyldopa or any component of the tablet
- Active liver disease or hepatitis — Methyldopa associated with drug-induced hepatitis
- History of Methyldopa-induced liver damage or haemolytic anaemia from previous use
- Phaeochromocytoma — centrally acting medicines ineffective and potentially dangerous
- Depression — Methyldopa worsens depressive symptoms significantly
- Currently taking MAO inhibitors — dangerous interaction causing excitation and hypertension
- Severe renal impairment — accumulation risk; dose reduction required
Side Effects
Common: Significant sedation and drowsiness — particularly when starting treatment (نیند آنا — خاص طور پر شروع میں), dry mouth, mild headache, dizziness especially on standing (اٹھتے وقت چکر), mild nausea, nasal congestion, mild oedema, fatigue — sedation is the most troublesome side effect and is dose-dependent; usually reduces after first 2 weeks.
Serious — Stop and seek emergency help immediately: Drug-induced hepatitis — yellowing of skin or eyes, fever, severe fatigue, and upper right abdominal pain (یرقان اور بخار — فوری ہسپتال جائیں), haemolytic anaemia — significant pallor, fatigue, and jaundice from immune-mediated red blood cell destruction (خون کی کمی — فوری مدد لیں), severe depression or suicidal thoughts — Methyldopa significantly worsens depression (فوری ڈاکٹر کو بتائیں), drug-induced lupus syndrome — joint pain with facial rash and fever, severe hypotension with fainting (بے ہوشی — فوری مدد لیں), parkinsonian symptoms — tremor and rigidity particularly in elderly patients, severe allergic reaction with swelling of face or throat.
Drug Interactions
| Medicine | Interaction |
|---|---|
| MAO inhibitors (Phenelzine, Tranylcypromine) | Dangerous excitation and hypertensive reaction — never combine; minimum 14-day gap required |
| Levodopa / Carbidopa | Methyldopa competes with Levodopa for absorption and central conversion — reduced Parkinson's control and increased side effects |
| Other antihypertensives | Additive blood pressure lowering — increased hypotension risk; monitor closely |
| Lithium | Methyldopa increases Lithium toxicity risk — monitor Lithium levels closely |
| Iron supplements (oral) | Iron significantly reduces Methyldopa absorption — take at least 2 hours apart |
| Antidepressants (TCAs) | Reduced antihypertensive effectiveness of Methyldopa |
| Phenothiazines (Chlorpromazine) | Additive central sedation and hypotension risk |
| Haloperidol | Combined use may cause dementia-like symptoms and confusion — use with caution |
| NSAIDs (Ibuprofen, Diclofenac) | Reduce antihypertensive effectiveness of Methyldopa |
| Alcohol (شراب) | Significantly increases central sedation — avoid completely |
Storage: Store below 25°C in a cool, dry place. Protect from moisture and direct sunlight. Keep out of reach of children (بچوں کی پہنچ سے دور رکھیں). Do not use after expiry date.
FAQs
Q: Why is Aldomet specifically recommended for blood pressure management during pregnancy when most other antihypertensives are avoided? Methyldopa has the longest and most extensively studied safety record in pregnancy — over 50 years of clinical use with no evidence of foetal harm, developmental effects, or adverse pregnancy outcomes at therapeutic doses. Most modern antihypertensives including ARBs, ACE inhibitors, and beta-blockers carry established foetal risks. This unique evidence base makes Aldomet the internationally recommended first-choice antihypertensive throughout all trimesters of pregnancy under obstetrician supervision.
Q: Why does Aldomet cause so much drowsiness and will it improve over time? Methyldopa's central mechanism — stimulating inhibitory alpha-2 receptors in the brainstem — produces significant sedation particularly when starting treatment or increasing dose. This is the most common reason patients discontinue the medicine. Sedation typically reduces meaningfully after 2 to 3 weeks as the body adapts — starting at the lowest effective dose and increasing gradually minimises this effect. Taking the largest dose at bedtime helps manage daytime sedation significantly.
Q: Does Aldomet require regular blood tests during long-term use? Yes — periodic liver function tests and blood counts are recommended during long-term Methyldopa therapy. Drug-induced hepatitis and immune haemolytic anaemia are rare but serious complications that can develop insidiously — liver function should be checked within the first 6 to 12 weeks of starting treatment and periodically thereafter. A positive Coombs test develops in up to 20% of long-term users — though frank haemolytic anaemia is much less common.
Medical Disclaimer: This information is for general awareness only and does not replace medical advice. Always consult a qualified doctor or pharmacist before taking any prescription medicine.