Pheochromocytoma in a Twelve-Year-Old Girl with SDHB-Related Hereditary Paraganglioma-Pheochromocytoma Syndrome

Table 2

Suggested algorithm for preoperative catecholamine blockade for PCC/PGL. Patients are best managed first with a pure alpha adrenergic blockade to relax arteriolar smooth muscles and reduce catecholamine-induced blood vessel constriction. Once the blood pressure is well-controlled, beta blockers can be added to treat tachycardia.

Medication	Recommended dose	Notes
Phenoxybenzamine	(i) Days 1-2: 0.2 mg/kg (max 10 mg) q12h; (ii) Days 3-4: 0.2 mg/kg q8h; (iii) Days 5-6: 0.2 mg/kg q6h; (iv) Days 7-8: 0.4 mg/kg (max 20 mg) q6h; (v) Days 9-10: 0.4 mg/kg qid; (vi) Days 11-12: 0.6 mg/kg (max 30 mg/dose) q6h; (vii) Days 13-14: 0.6–0.8 mg/kg q6h	(i) Goal is low normal blood pressure, at least below 50th percentile but preferably below 25th percentile; (ii) Side effects: congestion, tachycardia, hypotension, dizziness, especially when standing up (and true orthostatic hypotension), malaise, anorexia, and very rare allergic reactions; (iii) Simultaneously load the patient with salt and water to allow maximum blockade
Beta blockade	Propranolol 0.5 mg/kg/dose tid and advanced as necessary to keep HR <110	(i) Should never be used as a first agent; (ii) Helpful for symptomatic tachycardia; (iii) Begin 5–7 days after phenoxybenzamine

Notes that if the timetable for surgery must be compressed (so that surgical resection is planned 7-8 days after diagnosis), we consider advancing catecholamine blockade daily and using metyrosine to reduce amount of catecholamines produced by the tumor.