Phenoxybenzamine is used to treat high blood pressure and excessive sweating associated with pheochromocytoma.


What is Phenoxybenzamine?

Phenoxybenzamine is an alpha-blocker medication. It works by relaxing the blood vessels, thereby reducing blood pressure.


How should Phenoxybenzamine be taken?

Phenoxybenzamine is typically administered orally in the form of capsules.


Side effects associated with Phenoxybenzamine

Prolonged use of phenoxybenzamine may increase the risk of cancer. Among the other possible side effects of Phenoxybenzamine include the following:


  • Dizziness
  • Drowsiness
  • Nasal congestion
  • Stomach discomfort
  • Fatigue


It is important to contact a doctor immediately if you experience:


  • Rash
  • Urticaria
  • Itch
  • Difficulty breathing
  • Tightness in chest
  • Swelling of the mouth, face, lips or tongue
  • Sexual problems
  • Fainting
  • Rapid heartbeat
  • Growth of tumor masses
  • Constriction of the pupils
  • Severe dizziness or lightheadedness when sitting or standing up too quickly
  • Vomiting


Contraindications and warnings associated with the use of Phenoxybenzamine

Phenoxybenzamine can compromise the ability to drive or operate hazardous machinery, especially when it is taken together with alcohol or other drugs. It may also cause severe dizziness that can be aggravated by high temperatures, fever or strenuous physical exercise. For this reason, it is advisable to carefully get up from a lying or sitting position.


Before starting treatment with Phenoxybenzamine, it is important to tell your doctor if:


  • You have any allergies to the active substance, its excipients, or any other drugs or food
  • You are taking any other medications, herbal remedies or supplements. Mentioning in particular:  other medications to control high blood pressure, epinephrine, or reserpine levarterenol
  • You are suffering (or have suffered) from heart or blood vessel disorders, brain disorders, heart disease, arrhythmias, lung or respiratory tract infections, kidney disease or tumors
  • You are pregnant or breast-feeding