Guanethidine is used to treat hypertension in cases where other drugs cannot be used. It has been largely replaced by other drugs that do not cause orthostatic hypotension (lightheadedness). It can also be used to treat glaucoma and certain heart rhythm disorders.


What is Guanethidine?

Guanethidine is an antihypertensive drug that has a adrenergic blocking action. It acts by selectively inhibiting the transmission of adrenergic nerve fibers by preventing the release of norepinephrine from nerve endings. It also inhibits the activity of the sympathetic nervous system by reducing the amount of norepinephrine released after stimulation. Furthermore, it portrays anesthetic activity.


How should Guanethidine be taken?

Guanethidine is administered intramuscularly or orally in the form of sulphate.  


Side effects associated with Guanethidine

Among the most frequent side effects associated with the use of guanethidine include the following:


  • Diarrhea
  • Drowsiness
  • Fluid retention
  • Orthostatic hypotension


Contraindications and warnings associated with the use of Guanethidine

This drug should not be administered in people with heart failure.