Is guanethidine still available?

No, guanethidine has been [discontinued](https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=086113) and is no longer available in the United States. It's not clear why the medication was discontinued, but it's probably because newer medications are available.

Are there currently available medications that are used in place of guanethidine?

Yes, there are several available [medications used to treat high blood pressure](https://www.goodrx.com/conditions/hypertension/high-blood-pressure-medications) that are commonly used today. Examples include [ACE inhibitors](https://www.goodrx.com/classes/ace-inhibitors) (e.g., [lisinopril (Zestril)](https://www.goodrx.com/lisinopril/what-is)) and [beta blockers](https://www.goodrx.com/classes/beta-blockers) (e.g., [metoprolol (Lopressor)](https://www.goodrx.com/metoprolol/what-is)).

guanethidine

Generic Ismelin

Used for Hypertension

Guanethidine is a medication used for treating high blood pressure. It's no longer available in the United States because it was discontinued.

Reviewed by:

Robert Chad Hakim, PharmD, BCCCP

Allison Gourley, PharmD

Last reviewed on June 29, 2022

What is Guanethidine?

What is Guanethidine used for?

High blood pressure

Are you looking for information on guanfacine or guaifenesin (Mucinex) instead?

Drug facts

Common Brands	Ismelin(brand no longer available)
Drug Class	Adrenergic blocker
Controlled Substance Classification	Not a controlled medication
Generic Status	No lower-cost generic available
Availability	Discontinued

Common Brands

Ismelin(brand no longer available)

Drug Class

Adrenergic blocker

Controlled Substance Classification

Not a controlled medication

Generic Status

No lower-cost generic available

Availability

Discontinued

Common questions about Guanethidine

Guanethidine is an adrenergic blocker that's used to treat high blood pressure. It works by preventing the release of certain chemicals that constrict (tighten) your blood vessels. This causes your blood vessels to open up, which lowers your blood pressure.

No, Guanethidine has been discontinued and is no longer available in the United States. It's not clear why the medication was discontinued, but it's probably because newer medications are available.

Yes, there are several available medications used to treat high blood pressure that are commonly used today. Examples include ACE inhibitors (e.g., lisinopril (Zestril)) and beta blockers (e.g., metoprolol (Lopressor)).