Dosing & Uses
Dosage Forms & Strengths
tablet
- 0.3mg
- 0.45mg
- 0.625mg
- 0.9mg
- 1.25mg
powder for injection
- 25mg
Menopausal Vasomotor Symptoms, Atrophic Vaginitis/Kraurosis Vulvae
0.3 mg PO once daily in either continuous daily regimen or cyclic regimen (25 days on, 5 days off); adjusted PRN; use lowest dose that control symptoms; may be given daily if medical assessment warrants it
Female Hypogonadism
0.3-0.625 mg PO once daily in cyclic regimen (3 weeks on, 1 week off); may be titrated every 6-12 months; adjusted PRN; add progestin treatment should be added to maintain bone mineral density once skeletal maturity achieved
Osteoporosis
Prophylaxis
0.3 mg PO once daily in cyclic regimen (25 days on, 5 days off); adjusted PRN based on clinical response; may be given daily if medical assessment warrants it; administer lowest effective dose
May also be used in combination with medroxyprogesterone acetate
Prostate Cancer
Palliation only
1.25-2.5 mg PO q8hr
Abnormal Uterine Bleeding
25 mg IV/IM; repeated in 6-12 hours PRN or 25 mg IV repeated q4hr for 24 hr; if no response after 2 doses, re-evaluate therapy
Alternative regimen: 10-20 mg/day PO divided q4hr
May administer low dose medroxyprogesterone acetate with therapy or following therapy
Cyclic therapy: 25 days on, 5 days off; either 3 weeks on, 1 week off
Female Castration/Primary Ovarian Failure
1.25 mg PO once daily in cyclic regimen (25 days on, 5 days off); adjusted PRN; administer lowest effective dose
Breast Cancer Palliation
Metastatic disease in selected patients (males and females):10 mg PO q8hr for ≥3 months
Uremic Bleeding (Off-label)
0.6 mg/kg/day IV for 5 days
Safety and efficacy not established
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (2)
- fezolinetant
conjugated estrogens will increase the level or effect of fezolinetant by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated. Fezolinetant AUC and peak plasma concentration are increased if coadministered with drugs that are weak, moderate, or strong CYP1A2 inhibitors
- ospemifene
ospemifene, conjugated estrogens. Either increases effects of the other by pharmacodynamic synergism. Contraindicated.
Serious - Use Alternative (38)
- abametapir
abametapir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir.
abametapir will increase the level or effect of conjugated estrogens by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP1A2 substrates. If not feasible, avoid use of abametapir. - anastrozole
conjugated estrogens decreases effects of anastrozole by pharmacodynamic antagonism. Contraindicated.
- antithrombin alfa
conjugated estrogens decreases effects of antithrombin alfa by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- antithrombin III
conjugated estrogens decreases effects of antithrombin III by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- apalutamide
apalutamide will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- argatroban
conjugated estrogens decreases effects of argatroban by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- bemiparin
conjugated estrogens decreases effects of bemiparin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- bivalirudin
conjugated estrogens decreases effects of bivalirudin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- carbamazepine
carbamazepine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- cimetidine
cimetidine will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- clarithromycin
clarithromycin will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- dabrafenib
dabrafenib will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- dalteparin
conjugated estrogens decreases effects of dalteparin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- darunavir
darunavir will decrease the level or effect of conjugated estrogens by unspecified interaction mechanism. Avoid or Use Alternate Drug.
- enoxaparin
conjugated estrogens decreases effects of enoxaparin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- enzalutamide
enzalutamide will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- erythromycin base
erythromycin base will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- erythromycin ethylsuccinate
erythromycin ethylsuccinate will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- erythromycin lactobionate
erythromycin lactobionate will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- erythromycin stearate
erythromycin stearate will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- fexinidazole
fexinidazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.
- fondaparinux
conjugated estrogens decreases effects of fondaparinux by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- givosiran
givosiran will increase the level or effect of conjugated estrogens by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP1A2 substrates with givosiran. If unavoidable, decrease the CYP1A2 substrate dosage in accordance with approved product labeling.
- heparin
conjugated estrogens decreases effects of heparin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- idelalisib
idelalisib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates
- itraconazole
itraconazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- lorlatinib
lorlatinib will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- mitotane
mitotane will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- nefazodone
nefazodone will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- pacritinib
conjugated estrogens will decrease the level or effect of pacritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- phenindione
conjugated estrogens decreases effects of phenindione by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- pretomanid
pretomanid will increase the level or effect of conjugated estrogens by Other (see comment). Avoid or Use Alternate Drug. In vitro studies demonstrated that pretomanid significantly inhibits OAT3; monitor for increased adverse effects and consider dosage reduction for OAT3 substrates.
- protamine
conjugated estrogens decreases effects of protamine by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- quinidine
quinidine will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.
- rifabutin
rifabutin will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- rifampin
rifampin will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- St John's Wort
St John's Wort will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- tucatinib
tucatinib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.
Monitor Closely (164)
- albiglutide
conjugated estrogens decreases effects of albiglutide by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may decrease hypoglycemic effects of antidiabetics by impairing glucose tolerance. Monitor for glycemic control in diabetic patients.
- ambrisentan
ambrisentan will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
ambrisentan will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - amikacin
amikacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- amiodarone
amiodarone will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- amobarbital
amobarbital will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- aprepitant
aprepitant will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- armodafinil
armodafinil will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- artemether/lumefantrine
artemether/lumefantrine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- atazanavir
atazanavir, conjugated estrogens. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Atazanavir may increase or decrease levels of estrogens conjugated . Use alternatives if available.
- atogepant
conjugated estrogens will decrease the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- atorvastatin
atorvastatin will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- axitinib
conjugated estrogens decreases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- azithromycin
azithromycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Modify Therapy/Monitor Closely.
- aztreonam
aztreonam will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- bosentan
bosentan will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- budesonide
budesonide will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- butabarbital
butabarbital will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- butalbital
butalbital will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- cannabidiol
cannabidiol, conjugated estrogens. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Owing to the potential for both CYP1A2 induction and inhibition with the coadministration of CYP1A2 substrates and cannabidiol, consider reducing dosage adjustment of CYP1A2 substrates as clinically appropriate.
- cefadroxil
cefadroxil will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- cefamandole
cefamandole will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- cefpirome
cefpirome will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- cenobamate
cenobamate will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.
- cephalexin
cephalexin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- ceritinib
ceritinib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- chlorhexidine oral
chlorhexidine oral will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- ciprofloxacin
ciprofloxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- clarithromycin
clarithromycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Modify Therapy/Monitor Closely.
clarithromycin will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - clindamycin
clindamycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- clotrimazole
clotrimazole will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- conivaptan
conivaptan will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- cortisone
cortisone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- crofelemer
crofelemer increases levels of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 and transporters MRP2 and OATP1A2 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.
- cyclosporine
cyclosporine will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
cyclosporine will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
cyclosporine will increase the level or effect of conjugated estrogens by Other (see comment). Use Caution/Monitor. may increase plasma concentrations of organic anion transporter protein substrates - dapsone
dapsone will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- darifenacin
darifenacin will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- dasatinib
dasatinib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- deferasirox
deferasirox will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- demeclocycline
demeclocycline will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- dexamethasone
dexamethasone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- DHEA, herbal
DHEA, herbal will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- diltiazem
diltiazem will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- doxycycline
doxycycline will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- dronedarone
dronedarone will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
dronedarone will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - efavirenz
efavirenz will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- eluxadoline
eluxadoline increases levels of conjugated estrogens by decreasing metabolism. Use Caution/Monitor. Eluxadoline may increase the systemic exposure of coadministered OATP1B1 substrates.
- encorafenib
encorafenib, conjugated estrogens. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.
- ertapenem
ertapenem will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- erythromycin base
erythromycin base will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Modify Therapy/Monitor Closely.
erythromycin base will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - erythromycin ethylsuccinate
erythromycin ethylsuccinate will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Modify Therapy/Monitor Closely.
erythromycin ethylsuccinate will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - erythromycin lactobionate
erythromycin lactobionate will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Modify Therapy/Monitor Closely.
erythromycin lactobionate will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - erythromycin stearate
erythromycin stearate will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Modify Therapy/Monitor Closely.
erythromycin stearate will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - eslicarbazepine acetate
eslicarbazepine acetate will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- etravirine
etravirine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- exenatide injectable solution
conjugated estrogens decreases effects of exenatide injectable solution by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may decrease hypoglycemic effects of antidiabetics by impairing glucose tolerance. Monitor for glycemic control in diabetic patients.
- exenatide injectable suspension
conjugated estrogens decreases effects of exenatide injectable suspension by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may decrease hypoglycemic effects of antidiabetics by impairing glucose tolerance. Monitor for glycemic control in diabetic patients.
- fedratinib
fedratinib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
- felodipine
felodipine will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- fleroxacin
fleroxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- fluconazole
fluconazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- fludrocortisone
fludrocortisone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- fosamprenavir
fosamprenavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- fosaprepitant
fosaprepitant will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- fosfomycin
fosfomycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- fosphenytoin
fosphenytoin will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
fosphenytoin will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - gemifloxacin
gemifloxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- gentamicin
gentamicin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- grapefruit
grapefruit will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- griseofulvin
griseofulvin will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- hemin
conjugated estrogens decreases effects of hemin by pharmacodynamic antagonism. Use Caution/Monitor. Drugs that increase delta-aminolevulinic acid synthetase may decrease hemin effect.
- hyaluronidase
conjugated estrogens decreases effects of hyaluronidase by Other (see comment). Use Caution/Monitor. Comment: Enhanced tissue resistance to hyaluronidase.
- hydrocortisone
hydrocortisone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- indinavir
indinavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
indinavir will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - insulin degludec
conjugated estrogens decreases effects of insulin degludec by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may impair glucose tolerance.
- insulin degludec/insulin aspart
conjugated estrogens decreases effects of insulin degludec/insulin aspart by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may impair glucose tolerance.
- insulin inhaled
conjugated estrogens decreases effects of insulin inhaled by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may impair glucose tolerance.
- isavuconazonium sulfate
conjugated estrogens will decrease the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- istradefylline
istradefylline will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.
- ivosidenib
ivosidenib will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- ketoconazole
ketoconazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
ketoconazole will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - lamotrigine
conjugated estrogens decreases levels of lamotrigine by increasing hepatic clearance. Use Caution/Monitor.
- lapatinib
lapatinib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
lapatinib will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - lenacapavir
lenacapavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir (a moderate CYP3A4 inhibitor) may increase CYP3A4 substrates initiated within 9 months after last SC dose of lenacapavir, which may increase potential risk of adverse reactions of CYP3A4 substrates.
- levofloxacin
levofloxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- levoketoconazole
levoketoconazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
levoketoconazole will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - linezolid
linezolid will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- liraglutide
conjugated estrogens decreases effects of liraglutide by pharmacodynamic antagonism. Use Caution/Monitor. Estrogens may decrease hypoglycemic effects of antidiabetics by impairing glucose tolerance. Monitor for glycemic control in diabetic patients.
- lonapegsomatropin
conjugated estrogens will decrease the level or effect of lonapegsomatropin by Other (see comment). Use Caution/Monitor. Oral estrogens may reduce serum insulin-like growth factor-1 response to lonapegsomatropin. Patients receiving oral estrogen replacement may require higher lonapegsomatropin dosages.
- lopinavir
lopinavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- loratadine
loratadine will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- lovastatin
lovastatin will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- lumefantrine
lumefantrine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- maraviroc
conjugated estrogens increases levels of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Potential for increased toxicity. .
- marijuana
marijuana will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- meropenem
meropenem will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- meropenem/vaborbactam
meropenem/vaborbactam will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- metformin
conjugated estrogens decreases effects of metformin by pharmacodynamic antagonism. Use Caution/Monitor.
- methylprednisolone
methylprednisolone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- metronidazole
metronidazole will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
metronidazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. - miconazole vaginal
miconazole vaginal will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- mifepristone
mifepristone will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- minocycline
minocycline will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- moxifloxacin
moxifloxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- nefazodone
nefazodone will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- nelfinavir
nelfinavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- neomycin PO
neomycin PO will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- nevirapine
nevirapine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- nicardipine
nicardipine will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- nifedipine
nifedipine will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
nifedipine will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - nilotinib
nilotinib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
nilotinib will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - nitrofurantoin
nitrofurantoin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- ofloxacin
ofloxacin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- oxcarbazepine
oxcarbazepine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- oxytetracycline
oxytetracycline will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- paromomycin
paromomycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- pentobarbital
pentobarbital will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- phenobarbital
phenobarbital will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
phenobarbital will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - phenytoin
phenytoin will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
phenytoin will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. If the estrogen is being used for contraception then loss of contraception may occur. - pivmecillinam
pivmecillinam will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- posaconazole
posaconazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- prednisone
prednisone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- primidone
primidone will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- quercetin
quercetin will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- quinupristin/dalfopristin
quinupristin/dalfopristin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
quinupristin/dalfopristin will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. - ranolazine
ranolazine will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- ribociclib
ribociclib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- rifampin
rifampin will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- rifapentine
rifapentine will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- ritonavir
ritonavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
ritonavir will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - roxithromycin
roxithromycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Modify Therapy/Monitor Closely.
- rufinamide
rufinamide will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- saquinavir
saquinavir will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- secobarbital
secobarbital will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- simvastatin
simvastatin will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- sirolimus
sirolimus will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- somapacitan
conjugated estrogens decreases effects of somapacitan by Other (see comment). Modify Therapy/Monitor Closely. Comment: Oral estrogens may reduce the serum IGF-1 response to somapacitan. Patients may require higher somapacitan dosages. See drug monograph for starting dose recommendations.
- St John's Wort
St John's Wort will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- stiripentol
stiripentol, conjugated estrogens. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP1A2 inhibitor and inducer. Monitor CYP1A2 substrates coadministered with stiripentol for increased or decreased effects. CYP1A2 substrates may require dosage adjustment.
- streptomycin
streptomycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- sulfadiazine
sulfadiazine will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- sulfamethoxazole
sulfamethoxazole will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- sulfisoxazole
sulfisoxazole will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- tacrolimus
tacrolimus will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- tazemetostat
conjugated estrogens will decrease the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- tecovirimat
tecovirimat will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.
- teicoplanin
teicoplanin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- temocillin
temocillin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- tenapanor
tenapanor decreases levels of conjugated estrogens by Other (see comment). Use Caution/Monitor. Comment: Tenapanor (an inhibitor of intestinal uptake transporter, OATP2B1) may reduce the exposure of OATP2B1 substrates.
- teniposide
teniposide will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- tesamorelin
tesamorelin will decrease the level or effect of conjugated estrogens by altering metabolism. Use Caution/Monitor. May decrease efficacy; monitor
- tetracycline
tetracycline will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- ticarcillin
ticarcillin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- tigecycline
tigecycline will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- tobramycin
tobramycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- tolvaptan
tolvaptan will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- topiramate
topiramate will decrease the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- trazodone
trazodone will decrease the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- trimethoprim
trimethoprim will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- ubrogepant
conjugated estrogens will decrease the level or effect of ubrogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Dose adjustment is recommended with concomitant use of ubrogepant and moderate and weak CYP3A4 inducers. (see Dosage Modifications)
- valproic acid
conjugated estrogens will decrease the level or effect of valproic acid by increasing elimination. Modify Therapy/Monitor Closely. May lead to increased seizure frequency
- vancomycin
vancomycin will decrease the level or effect of conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- verapamil
verapamil will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
verapamil will increase the level or effect of conjugated estrogens by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - voriconazole
voriconazole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- zafirlukast
zafirlukast will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
Minor (39)
- acetazolamide
acetazolamide will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- amitriptyline
conjugated estrogens, amitriptyline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
- amoxapine
conjugated estrogens, amoxapine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
- anastrozole
anastrozole will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- androstenedione
androstenedione increases effects of conjugated estrogens by pharmacodynamic synergism. Minor/Significance Unknown.
- ascorbic acid
conjugated estrogens decreases levels of ascorbic acid by increasing elimination. Minor/Significance Unknown.
- boron
boron increases levels of conjugated estrogens by altering metabolism. Minor/Significance Unknown.
- clomipramine
conjugated estrogens, clomipramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
- cyanocobalamin
conjugated estrogens decreases levels of cyanocobalamin by altering metabolism. Minor/Significance Unknown.
- cyclophosphamide
cyclophosphamide will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- desipramine
conjugated estrogens, desipramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
- dosulepin
conjugated estrogens, dosulepin. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
- doxepin
conjugated estrogens, doxepin. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
- exemestane
conjugated estrogens decreases levels of exemestane by increasing metabolism. Minor/Significance Unknown.
- folic acid
conjugated estrogens decreases levels of folic acid by altering metabolism. Minor/Significance Unknown.
- imipramine
conjugated estrogens, imipramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
- isoniazid
isoniazid will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- L-methylfolate
conjugated estrogens decreases levels of L-methylfolate by altering metabolism. Minor/Significance Unknown.
- larotrectinib
larotrectinib will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- lofepramine
conjugated estrogens, lofepramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
- magnesium chloride
conjugated estrogens decreases levels of magnesium chloride by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- magnesium citrate
conjugated estrogens decreases levels of magnesium citrate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- magnesium hydroxide
conjugated estrogens decreases levels of magnesium hydroxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- magnesium oxide
conjugated estrogens decreases levels of magnesium oxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- magnesium sulfate
conjugated estrogens decreases levels of magnesium sulfate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- maprotiline
conjugated estrogens, maprotiline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
- metyrapone
conjugated estrogens decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- mycophenolate
mycophenolate decreases effects of conjugated estrogens by unknown mechanism. Minor/Significance Unknown. Clinical significance unclear.
- nortriptyline
conjugated estrogens, nortriptyline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
- phytoestrogens
phytoestrogens decreases effects of conjugated estrogens by pharmacodynamic antagonism. Minor/Significance Unknown.
- pleurisy root
pleurisy root decreases effects of conjugated estrogens by unspecified interaction mechanism. Minor/Significance Unknown. Theoretical interaction.
- progesterone, natural
progesterone, natural, conjugated estrogens. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Combination may produce breast tenderness.
- protriptyline
conjugated estrogens, protriptyline. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
- pyridoxine
conjugated estrogens decreases levels of pyridoxine by altering metabolism. Minor/Significance Unknown.
- pyridoxine (Antidote)
conjugated estrogens decreases levels of pyridoxine (Antidote) by altering metabolism. Minor/Significance Unknown.
- ropinirole
conjugated estrogens increases levels of ropinirole by unspecified interaction mechanism. Minor/Significance Unknown.
- rose hips
conjugated estrogens decreases levels of rose hips by increasing elimination. Minor/Significance Unknown.
- trazodone
conjugated estrogens, trazodone. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
- trimipramine
conjugated estrogens, trimipramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
Adverse Effects
>10%
Abdominal pain (15-17%)
Back pain (13-14%)
Breast enlargement
Breast tenderness (7-12%)
Headache (26-32%)
Arthralgia (7-14%)
Pharyngitis (10-12%)
Sinusitis (6-11%)
Diarrhea (6-7%)
1-10%
Depression (5-8%)
Dizziness (4-6%)
Nervousness (2-5%)
Flatulence (6-7%)
Vaginitis (5-7%)
Leukorrhea (4-7%)
Leg cramps (3-7%)
Increased cough (4-7%)
Pruritus (4-5%)
Frequency Not Defined
Amenorrhea
Breakthrough bleeding
Corneal curvation change
Melasma
Spotting
Vaginal moniliasis
Weight changes
Warnings
Black Box Warnings
Estrogens increase risk of endometrial cancer
- Close clinical surveillance of all women taking estrogens is important
- Adequate diagnostic measures, including endometrial sampling when indicated, should be undertaken to rule out malignancy in all cases of undiagnosed persistent or recurring abnormal vaginal bleeding
- There is no evidence that the use of "natural" estrogens results in a different endometrial risk profile than the use of synthetic estrogens at equivalent estrogen doses
Increased risk of breast cancer
- Using conjugated estrogens in combination with medroxyprogesterone increases risk of invasive breast cancer
Cardiovascular risks
- Estrogens with or without progestins should not be used to prevent cardiovascular disease
- Estrogens plus progestins: Women’s Health Initiative (WHI) Estrogen Plus Progestin substudy reported increased risks of myocardial infarction (MI), stroke, invasive breast cancer, pulmonary embolism (PE), and deep vein thrombosis (DVT) in postmenopausal women (aged 50-79 years) during 5.6 years of treatment with daily PO conjugated estrogens (0.625 mg) combined with medroxyprogesterone acetate (2.5 mg) in comparison with placebo
- Estrogens alone: A substudy of the WHI study reported increased risk for stroke and DVT in postmenopausal women (aged 50-79 years) during 6.8 years of treatment with daily PO conjugated estrogens (0.625 mg) alone in comparison with placebo
Dementia risks
- Estrogens with or without progestins should not be used to prevent dementia
- Women's Health Initiative Memory Study (WHIMS), a substudy of the WHI study, reported increased risk of developing probable dementia in postmenopausal women aged ≥65 years during 4 years of treatment with daily PO conjugated estrogens (0.625) mg combined with medroxyprogesterone acetate (2.5 mg) in comparison with placebo
- Estrogens alone: A substudy of the WHIMS reported increased risk of developing probable dementia in postmenopausal women aged ≥65 years during 5.2 years of treatment with daily PO conjugated estrogens (0.625 mg) alone in comparison with placebo
- Unknown whether these findings apply to younger postmenopausal women
Dose & duration
- In the absence of comparable data, these risks should be assumed to be similar for other doses of conjugated estrogens and medroxyprogesterone acetate, as well as for other combinations and dosage forms of estrogens and progestins
- Because of these risks, estrogens with or without progestins should be prescribed at the lowest effective dosage and for the shortest duration consistent with treatment goals and individual risks
Contraindications
Known anaphylactic reaction or angioedema
Known protein C, protein S, or antithrombin deficiency; other known thrombophilic disorders
Active or history of breast cancer
Arterial thromboembolic disease (stroke, MI), thrombophlebitis, DVT/PE, thrombogenic valvular disease
Liver disease, liver tumors
Uncontrolled hypertension, diabetes mellitus with vascular involvement, jaundice with previous oral contraceptive use
Estrogen-dependent neoplasia
Undiagnosed abnormal vaginal bleeding
Cautions
Use caution in diabetes mellitus, hyperlipidemias, hypertension, hypothyroidism, advanced age, hepatic or renal impairment, uterine leiomyomata, porphyria, patients with defects of lipoprotein metabolism, hypertriglyceridemia, ovarian cancer, systemic lupus erhythematosus, exacerbation of endometriosis or other conditions, smoking, diseases exacerbated by fluid retention
Manage appropriately risk factors for arterial vascular disease (e.g., hypertension, diabetes mellitus, tobacco use, hypercholesterolemia, and obesity) and/or venous thromboembolism (e.g., personal history or family history of VTE, obesity, and systemic lupus erythematosus)
In patients with pre-existing hypertriglyceridemia, estrogen therapy may be associated with elevations of plasma triglycerides leading to pancreatitis and other complications
Estrogens may be poorly metabolized in patients with impaired liver function; exercise caution in patients with a history of cholestatic jaundice associated with past estrogen use or with pregnancy; in the case of recurrence, discontinue medication
Patients dependent on thyroid hormone replacement therapy who are also receiving estrogens may require increased doses of thyroid replacement therapy; these patients should have their thyroid function monitored in order to maintain their free thyroid hormone levels in an acceptable range
A 2 to 4-fold increase in risk of gallbladder disease requiring surgery in postmenopausal women receiving estrogens reported
Retinal vascular thrombosis reported in patients receiving estrogens; discontinue medication pending examination if there is sudden partial or complete loss of vision, or a sudden onset of proptosis, diplopia, or migraine; if examination reveals papilledema or retinal vascular lesions, estrogens should be discontinued
There are, possible risks that may be associated with use of progestins with estrogens compared to estrogen-alone regimens, including a possible increased risk of breast cancer, adverse effects on lipoprotein metabolism (e.g., lowering HDL, raising LDL), and impairment of glucose tolerance
Discontinue if any of the following develop: Jaundice, signs of venous thromboembolism, visual problems (may cause contact lens intolerance), massive blood pressure increase, major surgery or prolonged immobilization occurring in 4 weeks, new migraine, depression
Women with protein C or S deficiency (inherited thrombophilia), may have increased risk of venous thromboembolism
Do not use with conditions that predispose to hyperkalemia
Conditions exacerbated by fluid retention (asthma, epilepsy, migraines, cardiac or renal dysfunction)
Risk of hypercalcemia in patients with breast cancer and bone metastases
Increased risk of ovarian and endometrial cancer reported in women who used hormonal therapy for menopausal symptoms
Long-term postmenopausal estrogen treatment has been associated with increased risk of breast cancer, MI, stroke, DVT/PE, and dementia
Patients on warfarin or other oral anticoagulants: Estrogens increase thromboembolic risk; increase in anticoagulant dosage may be warranted
Discontinue therapy if pancreatitis occurs; estrogen compounds generally associated with increased triglyceride levels
Cases of anaphylaxis and angioedema have been reported; exogenous estrogens may exacerbate symptoms of angioedema in women with hereditary angioedema
Use caution in individuals with severe hypocalcemia
Pregnancy & Lactation
Pregnancy category: X
Lactation: Use controversial; estrogens are excreted into breast milk in small quantities; use with caution
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Replaces endogenous estrogen; important for development and maintenance of female reproductive system and secondary sexual characteristics
Antiandrogenic effect provides benefit in prostate cancer
Absorption
Bioavailability: Readily absorbed from gastrointestinal (GI) tract
Onset: 2-4 weeks (PO-menopause)
Peak plasma time: 7 hr (PO)
Distribution
Protein bound: 80%
Metabolism
Metabolized in liver to inactive sulfates and glucuronides
Metabolites: Estradiol, estrone, estriol
Elimination
Excretion: Mainly in urine as conjugates with small amount of unchanged drug; most estrogens are also excreted in bile and undergo enterohepatic recycling
Administration
IV Incompatibilities
Additive, syringe, Y-site: Ascorbic acid, acidic solutions, protein hydrolysate
IV Compatibilities
Solution: D5W, NS, invert sugar solutions
Y-site: Heparin/hydrocortisone, potassium chloride, vitamins B and C
IV Preparation
Reconstitute with 5 mL of diluent provided
First withdraw air from vial, then add diluent slowly and aseptically with gentle agitation
Stable at 2-8°C for 60 days
Do not use if agent darkens or precipitates
IV/IM Administration
IM: Acceptable
IV: Administer slowly to avoid flushing reaction
Infusion not recommended; injection into running infusion can be performed
Storage
Refrigerate reconstituted injection
Intact vials are stable for 24 months at room temperature
Images
| BRAND | FORM. | UNIT PRICE | PILL IMAGE |
|---|---|---|---|
| Premarin vaginal - | 0.625 mg/gram cream |  | |
| Premarin oral - | 0.625 mg tablet |  | |
| Premarin oral - | 0.45 mg tablet |  | |
| Premarin oral - | 0.3 mg tablet |  | |
| Premarin oral - | 0.625 mg tablet | | |
| Premarin oral - | 1.25 mg tablet |  | |
| Premarin oral - | 0.9 mg tablet |  | |
| Premarin injection - | 25 mg vial |  |
Copyright © 2010 First DataBank, Inc.
Patient Handout
conjugated estrogens injection
NO MONOGRAPH AVAILABLE AT THIS TIME
USES: Consult your pharmacist.
HOW TO USE: Consult your pharmacist.
SIDE EFFECTS: Consult your pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Consult your pharmacist.
DRUG INTERACTIONS: Consult your pharmacist.Keep a list of all your medications with you, and share the list with your doctor and pharmacist.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
NOTES: No monograph available at this time.
MISSED DOSE: Consult your pharmacist.
STORAGE: Consult your pharmacist.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.
Information last revised July 2016. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Formulary
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