Estrogens are relatively contraindicated during breast-feeding because they are secreted in milk and cause unpredictable effects in the infant. An alternative feeding method should be used. Estrogens are relatively contraindicated in children because estrogens promote epiphysial closure. Blood pressure can increase during therapy with estrogens. Patients with hypertension should be monitored closely for increases in blood pressure if estrogens are administered.
Estrogens can cause amenorrhea and interfere with the effects of bromocriptine.
Concurrent use is not recommended. Estrogens can increase calcium absorption. In general, the interaction between calcium salts and estrogen is beneficial and is used to therapeutic advantage in postmenopausal women who have osteoporosis. Estrogens can inhibit the metabolism of cyclosporine. Estrogens should be avoided whenever possible in patients receiving cyclosporine.