Case Reports in Genetics / 2014 / Article / Tab 2

Case Report

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.

MedicationRecommended doseNotes

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 blockadePropranolol 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.