You should take it as long as your doctor has recommended it to you. Do not stop taking it without talking to you doctor first. Long-term use of Phenoxybenzamine is not recommended as cases of developing cancer have been reported. Consult your doctor before starting the treatment.

Phenoxybenzamine should not be given to patients who are allergic to it. Additionally, in patients with a recent history (within the last month) of stroke or heart attack, Phenoxybenzamine should be avoided. Tell your doctor if any of these conditions apply to you.

Phenoxybenzamine belongs to alpha receptor blockers class of medicines. Alpha receptors blockade decreases resistance thereby increasing blood flow to the skin, mucosa (membrane that lines various cavities of the body), and abdominal viscera (membrane lining the abdomen). This results in lowering of blood pressure. This reduced blood pressure and increased release of chemical messenger (noradrenaline) results in reflex tachycardia.

Phenoxybenzamine helps in reducing the increased blood pressure caused by Pheochromocytoma. It is a tumor of the adrenal glands. It causes the release of certain substances (catecholamines) from the adrenal glands into the bloodstream in large quantities, causing high blood pressure. Phenoxybenzamine works by blocking alpha receptors, thereby decreasing blood pressure.

Using Phenoxybenzamine in pheochromocytoma is beneficial due to its long duration of action leading to twice daily dosing. Along with that, it prevents episodic increase of catecholamine releases during pre- and post-operative period which helps in keeping the blood pressure under control during surgical procedures.

Phenoxybenzamine is sometimes effective in treating Raynaud’s phenomenon. This condition results in discoloration of the fingers and/or toes after exposure to changes in temperature (cold or hot) or emotional events. Phenoxybenzamine is also useful in treating frostbite.

Yes, use of Phenoxybenzamine may affect sex life. It may cause inhibition of ejaculation and may make the patient impotent. However, these effects are generally mild and lasts for only a short time. Discuss with your doctor if you experience this.

Taking more than the recommended dose of Phenoxybenzamine may cause significant decrease in blood pressure which may last for several hours, increased heartbeat, and one may even collapse. If you accidentally take an overdose of this medicine, contact your doctor and seek immediate medical help.