Efficacy and safety of metyrosine in pheochromocytoma/paraganglioma: a multi-center trial in Japan.

Efficacy and safety of metyrosine in pheochromocytoma/paraganglioma: a multi-center trial in Japan. Endocr J. 2018 Jan 20;: Authors: Naruse M, Satoh F, Tanabe A, Okamoto T, Ichihara A, Tsuiki M, Katabami T, Nomura M, Tanaka T, Matsuda T, Imai T, Yamada M, Harada T, Kawata N, Takekoshi K Abstract To assess the efficacy, safety, and pharmacokinetics of metyrosine (an inhibitor of catecholamine synthesis) in patients with pheochromocytoma/paraganglioma (PPGL), we conducted a prospective, multi-center, open-label study at 11 sites in Japan. We recruited PPGL patients aged ≥12 years requiring preoperative or chronic treatment, receiving α-blocker treatment, having baseline urinary metanephrine (uMN) or normetanephrine (uNMN) levels ≥3 times the upper limit of normal values, and having symptoms associated with excess catecholamine. Metyrosine treatment was started at 500 mg/day and modified according to dose-adjustment criteria up to 4,000 mg/day. The main outcome measure was the proportion of patients who achieved at least 50% reduction in uMN or uNMN levels from baseline. Sixteen patients (11 males/5 females) aged 12-86 years participated. After 12 weeks of treatment and at the last evaluation of efficacy, the primary endpoint was achieved in 31.3% of all patients, including 66.7% of those under preoperative treatment and 23.1% of those under chronic treatment. Sedation, anemia, and death were reported in 1 patient each as serious a...
Source: Endocrine Journal - Category: Endocrinology Tags: Endocr J Source Type: research