antihypotensive
{{Short description|Substance that raises blood pressure}}
{{Redirect|Vasopressor|the homonymous hormone|vasopressin}}
An antihypotensive, also known as a vasopressor, is an agent that raises blood pressure by constricting blood vessels, thereby increasing systemic vascular resistance. This is different from inotropes which increase the force of cardiac contraction. Some substances do both (e.g. dopamine, dobutamine).
If low blood pressure is due to blood loss, then preparations increasing volume of blood circulation—plasma-substituting solutions such as colloid and crystalloid solutions (salt solutions){{cite web |url= https://www.nice.org.uk/guidance/cg174/chapter/1-recommendations|title= Intravenous fluid therapy in adults in hospital |author= |date= May 2017|website= NICE |access-date= October 19, 2018}}—will raise the blood pressure without any direct vasopressor activity. Packed red blood cells, plasma or whole blood should not be used solely for volume expansion or to increase oncotic pressure of circulating blood.{{Medical citation needed|date=October 2018}} Blood products should only be used if reduced oxygen carrying capacity or coagulopathy is present.{{Medical citation needed|date=October 2018}} Other causes of either absolute (dehydration, loss of plasma via wound/burns) or relative (third space losses) vascular volume depletion also respond, although blood products are only indicated if significantly anemic.
Classification
Antihypotensive agents can be classified as follows:{{citation needed|date=June 2019}}
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- Sympathomimetics
- Epinephrine
- Noradrenaline
- Phenylephrine
- Dobutamine
- Dopamine
- Dopexamine
- Ephedrine
- Midodrine
- Amezinium
- Metaraminol
- Vasopressin
- Angiotensinamide
- S-alkylisothiouronium derivatives
- Difetur
- Izoturon
- Glucocorticoids and mineralocorticoids
- Hydrocortisone
- Prednisone, Prednisolone
- Dexamethasone, Betamethasone
- Fludrocortisone
- Positive inotropic agents
- Cardiac glycosides
- Strophantin K
- Convallatoxin
- Digoxin
- PDE3 inhibitors
- Amrinone
- Enoximone
- Milrinone
- Levosimendan
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