Management

Definitive treatment is by surgical resection of the tumour, normally using a laparoscopic approach.

Prior to surgery the acute crisis is treated medically to control the effects of excess catecholamines.  This is normally achieved by alpha adrenoceptor blockade.

Phenoxybenzamine is advocated as it blocks adrenoceptors by destroying them and therefore its effect cannot be overcome by increasing catecholamine concentrations.  Phentolamine and Doxazosin are alternative alpha antagonists.

Phenoxybenzamine

Used in the treatment of hypertensive crisis.  The main action is vasodilatation by non competitive antagonism of alpha adrenoceptors.

The dose by IV administration is 10-40 mg over 1 hour.  It acts in 1 hour and effects last for 3-4 days.  It can be given orally 10-60 mg/day in divided doses.

Side effects include:  Hypotension, dizziness, sedation, a dry mouth, paralytic ileus and impotence.

Phentolamine

Used in the diagnosis and perioperative management of phaeochromocytoma.  It causes vasodilatation, but also positive ino and chronotropism.  It exerts its effect predominantly by competitive alpha adrenoceptor blockade.

The adult intramuscular dose for control of paroxysmal hypertension is 5-10 mg.

Side effects include orthostatic hypotension, dizziness, abdominal discomfort and diarrhoea.  Cardiovascular collapse has occurred following treatment of phaeochromocytoma.

Beta adrenoceptor blockade can be instituted to control tachycardia, but this should only be done after adequate alpha blockade, otherwise unopposed beta blockade can lead to worsening hypertension.

Patients may also require additional therapy to treat additional problems such as arrhythmias.  Many patients require IV fluid as they are relatively fluid depleted.  These additional therapies should be tailored on a case by case basis [3,5,6].

Important: Beta blockade should not be used as sole therapy to control hypertension as unopposed beta blockade can lead to worsening hypertension.

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