Roberts J T, Bates T, Bozzino J M, Brock J E, Clarke D G, Durrant K R, Evans R G, Tobias J S
Department of Radiotherapy, Newcastle General Hospital, Newcastle-upon-Tyne.
Clin Oncol (R Coll Radiol). 1990 Nov;2(6):324-7. doi: 10.1016/s0936-6555(05)80994-x.
Medroxyprogesterone acetate (MPA) is regarded as a valuable hormonal therapy for metastatic breast cancer. The drug is manufactured by more than one pharmaceutical company, and one particular brand of oral MPA (Provera Tablets, Upjohn) has been reformulated to incorporate micronized particles, providing significantly enhanced bioavailability. The response rate and side-effect data from a pilot study, which used the old formulation Provera Tablets 100 mg at a dosage of 800 mg/day in 28 patients with recurrent breast cancer after treatment with tamoxifen, are compared with those from another study in which 59 similar patients received 800 mg/day of new formulation Provera Tablets 200 mg. Neither of these studies, conducted in the United Kingdom, has previously been published. The response rates were similar in both studies, but there were higher incidences of significant weight gain and increased blood pressure in those patients treated with the new formulation. These side effects have been noticed by other workers employing new formulation MPA at a dosage of 800 mg per day, while it has been reported that reducing the dosage to 400 mg perday is accompanied by a lower incidence of side effects, without affecting the response rate. It is concluded that the increased serum levels of MPA, made possible by the micronized product, do not favourably influence the response of metastatic breast cancer to therapy, but may be associated with a higher incidence of side effects. Reducing the dosage of the new formulation MPA to 400 mg/day may allow a more acceptable side-effect profile, without loss of therapeutic efficacy. Such a dose reduction would make this brand of MPA more cost effective.
醋酸甲羟孕酮（MPA）被视为转移性乳腺癌的一种重要激素疗法。该药物由多家制药公司生产，其中一种特定品牌的口服MPA（普维拉片，优普强公司生产）已重新配方，加入了微粉化颗粒，显著提高了生物利用度。一项试点研究使用旧配方的100毫克普维拉片，剂量为800毫克/天，对28例他莫昔芬治疗后复发的乳腺癌患者进行治疗，将其缓解率和副作用数据与另一项研究进行比较，在另一项研究中，59例类似患者接受了800毫克/天的新配方200毫克普维拉片。这两项在英国进行的研究此前均未发表。两项研究的缓解率相似，但使用新配方治疗的患者体重显著增加和血压升高的发生率更高。其他使用800毫克/天新配方MPA的研究人员也注意到了这些副作用，同时有报道称将剂量降至400毫克/天副作用发生率较低，且不影响缓解率。得出的结论是，微粉化产品使MPA血清水平升高，对转移性乳腺癌治疗反应没有有利影响，但可能与更高的副作用发生率相关。将新配方MPA的剂量降至400毫克/天可能会使副作用情况更易接受，且不损失治疗效果。这样的剂量降低将使该品牌的MPA更具成本效益。
