Phentolamine is a medication that blocks the effects of a hormone called norepinephrine. Norepinephrine is responsible for constricting blood vessels, increasing heart rate, and other effects related to the "fight or flight" response. By blocking norepinephrine, phentolamine can help to:
- Lower blood pressure: Phentolamine can be used to treat high blood pressure, particularly in cases where other medications have not been effective.
- Treat pheochromocytoma: This is a rare tumor that produces excessive amounts of norepinephrine. Phentolamine can help to control the symptoms of pheochromocytoma, such as high blood pressure, headaches, and sweating.
- Reverse the effects of certain medications: Phentolamine can be used to reverse the effects of some medications that constrict blood vessels, such as those used to treat certain types of shock.
Phentolamine is usually given by injection, but it can also be taken orally.
Important Note: Phentolamine is a powerful medication that can have serious side effects. It should only be used under the supervision of a doctor.
