methyldopa vs vasopressin
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Side-by-side comparison of methyldopa and vasopressin. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
minor Known Drug Interaction
7.4 Drugs Suspected of Causing SIADH Use with drugs suspected of causing SIADH (e.g., SSRIs, tricyclic antidepressants, haloperidol, chlorpropamide, enalapril, methyldopa, pentamidine, vincristine, cyclophosphamide, ifosfamide, felbamate) may increase the pressor effect in addition to the antidiuretic effect of Vasopressin injection.
Aldomet
Vasostrict
Methyldopa is a medicine used to treat high blood pressure. It helps to lower your blood pressure.
Vasopressin injection helps raise blood pressure in adults with shock. It is used when fluids and other medicines don't work well enough.
Methyldopa is used to treat hypertension, which is also known as high blood pressure. High blood pressure can strain the heart and blood vessels. Lowering blood pressure can reduce the risk of strokes, heart attacks, and kidney problems.
Vasopressin injection is used to increase blood pressure. It is for adults who have vasodilatory shock. This is when blood vessels relax too much, causing low blood pressure. It is used when fluids and other medicines called catecholamines are not enough to raise blood pressure.
Methyldopa lowers blood pressure by affecting certain chemicals in your brain. These chemicals help to relax blood vessels, which allows blood to flow more easily. This results in lower blood pressure.
Vasopressin is a hormone that makes blood vessels get tighter. This helps to increase blood pressure. It can also affect how your kidneys handle water.
- • Sedation
- • Headache
- • Weakness
- • Decreased heart output
- • Slow heart rate
- • Fast or irregular heart rate
- • Low sodium levels in the blood
- • Reduced blood flow to the heart
- Foetal Exposure During Pregnancy 1,261
- Premature Baby 888
- Maternal Exposure During Pregnancy 794
- Exposure During Pregnancy 654
- Premature Delivery 561
- Hypotension 486
- Cardiogenic Shock 389
- Sepsis 380
- Multiple Organ Dysfunction Syndrome 375
- Condition Aggravated 359
You should not take methyldopa if you have active liver disease like hepatitis or cirrhosis. Also, do not take it if you have had liver problems caused by methyldopa in the past. Do not take it if you are allergic to any of the ingredients in methyldopa. You should not take this medicine if you are taking a monoamine oxidase (MAO) inhibitor.
Vasopressin can worsen heart function. It can also cause a type of diabetes where you pee a lot. Your doctor will check your electrolytes and urine after you stop taking it.
Tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. Methyldopa can pass into breast milk. Talk to your doctor about the risks and benefits.
Vasopressin may cause the uterus to contract, which could be a problem during pregnancy. Tell your doctor if you are pregnant or plan to become pregnant. It is not known if vasopressin passes into breast milk.
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How to Read This methyldopa vs vasopressin Comparison
methyldopa is classified in the Central Alpha-2 Agonist drug class, while vasopressin sits within the Vasopressin Receptor Agonist class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, methyldopa has 4,158 submissions while vasopressin has 1,989. Those figures reflect cumulative reporting volume, not per-patient risk, so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known minor interaction flagged in FDA labeling, attributed to methyldopa can cause the body to retain extra water, which boosts the blood pressure and water-saving effects of vasopressin.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.
A table cannot represent individual circumstances. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This registry does not provide medical, treatment, substitution, or medication-change directions for methyldopa or vasopressin.
Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.