Dosing & Uses
Dosage Forms & Strengths
mestranol/norethindrone
tablet
- 50mcg/1mg
Oral Contraceptive
1 hormonally active tablet qDay for 21 days, THEN 1 inert tablet (or tablet-free) for 7 days, repeat cycle
Follow manufacturer's color-coding (active vs inert)
Start on Day 1 of menstrual cycle or Sunday following start of menses
Initiating after Pregnancy
Increased risk for venous thromboembolism following delivery with combined hormonal contraceptives; risk declines rapidly after 21 days, but does not return to normal until 42 days after delivery
CDC guidelines recommend waiting 3-6 weeks in postpartum women without additional VTE risks (MMWR July 7, 2011)
Initiating after vaginal birth: Wait at least 3 weeks
Initiating after caesarean section birth: Wait at least 6 weeks
Women with other risk factors for VTE in addition to postpartum: Do not use combined hormonal contraceptives
Renal Impairment
Use caution; monitor blood presssure
Hepatic Impairment
Do not administer
Safety and efficacy not established
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (1)
- tranexamic acid oral
tranexamic acid oral, mestranol. Either increases toxicity of the other by pharmacodynamic synergism. Contraindicated. Coadministration of tranexamic acid oral and combination hormonal contraceptives increases thrombotic risk .
Serious - Use Alternative (54)
- abametapir
abametapir will increase the level or effect of mestranol 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.
- amobarbital
amobarbital decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in contraceptive failure.
- antithrombin alfa
mestranol decreases effects of antithrombin alfa by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- antithrombin III
mestranol decreases effects of antithrombin III by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- apalutamide
apalutamide will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.
- argatroban
mestranol decreases effects of argatroban by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- bemiparin
mestranol decreases effects of bemiparin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- bivalirudin
mestranol decreases effects of bivalirudin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- brigatinib
brigatinib will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Brigatinib induces CYP3A4 in vitro. Coadministration of hormonal contraceptives with brigatinib can result in decreased concentrations and loss of efficacy. Brigatinib can cause fetal harm. Women should use an effective nonhormonal method of contraception during treatment and for at least 4 months after the last brigatinib dose.
- butabarbital
butabarbital decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in contraceptive failure.
- butalbital
butalbital decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in contraceptive failure.
- carbamazepine
carbamazepine will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
carbamazepine decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in loss of contraceptive efficacy. - cimetidine
cimetidine will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- clarithromycin
clarithromycin will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- dalteparin
mestranol decreases effects of dalteparin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- elagolix
mestranol decreases effects of elagolix by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Based on the mechanism of action of elagolix, estrogen-containing contraceptives are expected to reduce elagolix efficacy. Effects of progestin-only contraceptives on the efficacy of elagolix is unknown. Advise women to use nonhormonal contraceptives during treatment with elagolix and for 1 week after discontinuing elagolix.
- enoxaparin
mestranol decreases effects of enoxaparin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- enzalutamide
enzalutamide will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- erythromycin base
erythromycin base will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- erythromycin ethylsuccinate
erythromycin ethylsuccinate will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- erythromycin lactobionate
erythromycin lactobionate will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- erythromycin stearate
erythromycin stearate will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- ethotoin
ethotoin decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in contraceptive failure.
- fedratinib
mestranol will increase the level or effect of fedratinib by Other (see comment). Avoid or Use Alternate Drug. Avoid coadministration of fedratinib (a CYP3A4 and CYP2C19 substrate) with dual CYP3A4 and CYP2C19 inhibitor. Effect of coadministration of a dual CYP3A4 and CYP2C19 inhibitor with fedratinib has not been studied.
- fexinidazole
fexinidazole will increase the level or effect of mestranol 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
mestranol decreases effects of fondaparinux by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- fosphenytoin
fosphenytoin decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in contraceptive failure.
- heparin
mestranol decreases effects of heparin by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- idelalisib
idelalisib will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates
- ivosidenib
ivosidenib will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternative therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.
ivosidenib will decrease the level or effect of mestranol by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP2C9 substrates with ivosidenib or replace with alternate therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs. - ketoconazole
ketoconazole will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- levoketoconazole
levoketoconazole will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- lonafarnib
mestranol will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of lonafarnib (a sensitive CYP3A substrate) with weak CYP3A inhibitors is unavoidable, reduce to, or continue lonafarnib at starting dose. Closely monitor for arrhythmias and events (eg, syncope, heart palpitations) since lonafarnib effect on QT interval is unknown.
- lopinavir
lopinavir will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- lorlatinib
lorlatinib will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- mifepristone
mifepristone will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
- nefazodone
nefazodone will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- nevirapine
nevirapine decreases levels of mestranol by unknown mechanism. Contraindicated.
- pentobarbital
pentobarbital decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in contraceptive failure.
- phenindione
mestranol decreases effects of phenindione by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- phenobarbital
phenobarbital decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in contraceptive failure.
- phenytoin
phenytoin decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in contraceptive failure.
- primidone
primidone decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. Contraceptive failure may result.
- protamine
mestranol decreases effects of protamine by pharmacodynamic antagonism. Contraindicated. Risk of thromboembolic disorders.
- quinidine
quinidine will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.
- rifabutin
rifabutin will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
rifabutin decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in contraceptive failure. - rifampin
rifampin will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
rifampin decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in contraceptive failure. - rifapentine
rifapentine decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in contraceptive failure.
- saquinavir
saquinavir will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- secobarbital
secobarbital decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in contraceptive failure.
- St John's Wort
St John's Wort will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- tipranavir
tipranavir decreases levels of mestranol by increasing metabolism. Avoid or Use Alternate Drug. May result in contraceptive failure.
tipranavir will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. - tucatinib
tucatinib will increase the level or effect of mestranol 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.
- voxelotor
voxelotor will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.
Monitor Closely (178)
- albiglutide
mestranol decreases effects of albiglutide by pharmacodynamic antagonism. Use Caution/Monitor. Oral contraceptives may decrease hypoglycemic effects of antidiabetics by impairing glucose tolerance. Monitor for glycemic control in diabetic patients.
- alpelisib
alpelisib will decrease the level or effect of mestranol by affecting hepatic enzyme CYP2C9/10 metabolism. Modify Therapy/Monitor Closely.
- amikacin
amikacin will decrease the level or effect of mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- aminocaproic acid
mestranol decreases effects of aminocaproic acid by pharmacodynamic antagonism. Use Caution/Monitor. Risk of thromboembolic disorder.
- amiodarone
amiodarone will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- amobarbital
amobarbital will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- amoxicillin
amoxicillin will decrease the level or effect of mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- ampicillin
ampicillin will decrease the level or effect of mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- apalutamide
apalutamide will decrease the level or effect of mestranol by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. Coadministration of apalutamide, a weak CYP2C9 inducer, with drugs that are CYP2C9 substrates can result in lower exposure to these medications. Evaluate for loss of therapeutic effect if medication must be coadministered.
- aprepitant
aprepitant will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- armodafinil
armodafinil will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- artemether/lumefantrine
artemether/lumefantrine will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- atazanavir
atazanavir will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- atogepant
mestranol will increase 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 mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- avapritinib
mestranol will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- axitinib
mestranol increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- azithromycin
azithromycin will decrease the level or effect of mestranol 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 mestranol 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- budesonide
budesonide will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- butabarbital
butabarbital will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- butalbital
butalbital will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- cannabidiol
cannabidiol will decrease the level or effect of mestranol by decreasing metabolism. Modify Therapy/Monitor Closely. Cannabidiol may potentially inhibit CYP2C9 activity. Consider reducing the dose when concomitantly using CYP2C9 substrates.
- cefaclor
cefaclor will decrease the level or effect of mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- cefadroxil
cefadroxil will decrease the level or effect of mestranol 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 mestranol 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 mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- cefprozil
cefprozil will decrease the level or effect of mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- ceftibuten
ceftibuten will decrease the level or effect of mestranol 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 mestranol 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 mestranol 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- chlorhexidine oral
chlorhexidine oral will decrease the level or effect of mestranol 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 mestranol 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 mestranol 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 mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - clindamycin
clindamycin will decrease the level or effect of mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- clobazam
clobazam will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Clobazam is a weak CYP3A4 inducer; effectiveness of hormonal contraceptives may be diminished when given concurrently with clobazam. Additional non-hormonal forms of contraception are recommended.
- clotrimazole
clotrimazole will decrease the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- conivaptan
conivaptan will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- cortisone
cortisone will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- cyclosporine
cyclosporine will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
cyclosporine will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
mestranol increases levels of cyclosporine by unknown mechanism. Use Caution/Monitor. - dabrafenib
dabrafenib will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.
- dapsone
dapsone will decrease the level or effect of mestranol 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- darunavir
darunavir will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- dasatinib
dasatinib will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- deferasirox
deferasirox will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- demeclocycline
demeclocycline will decrease the level or effect of mestranol 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- DHEA, herbal
DHEA, herbal will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- dicloxacillin
dicloxacillin will decrease the level or effect of mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- doxycycline
doxycycline will decrease the level or effect of mestranol 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
dronedarone will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - efavirenz
efavirenz will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- elagolix
elagolix decreases levels of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.
- elvitegravir/cobicistat/emtricitabine/tenofovir DF
elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.
elvitegravir/cobicistat/emtricitabine/tenofovir DF decreases levels of mestranol by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. Elvitegravir is a moderate CYP2C9 inducer. - encorafenib
encorafenib, mestranol. 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 mestranol 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 mestranol 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 mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - erythromycin ethylsuccinate
erythromycin ethylsuccinate will decrease the level or effect of mestranol 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 mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - erythromycin lactobionate
erythromycin lactobionate will decrease the level or effect of mestranol 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 mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - erythromycin stearate
erythromycin stearate will decrease the level or effect of mestranol 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 mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - eslicarbazepine acetate
eslicarbazepine acetate will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- ethotoin
mestranol decreases effects of ethotoin by decreasing metabolism. Use Caution/Monitor.
- etravirine
etravirine will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- exenatide injectable solution
mestranol, exenatide injectable solution. Other (see comment). Use Caution/Monitor. Comment: Oral contraceptives may decrease hypoglycemic effects of antidiabetics by impairing glucose tolerance. The effect of exenatide to slow gastric emptying may reduce the extent and rate of oral medications that require rapid GI absorption. Advise patients to take oral contraceptives at least 1 hr before exenatide. .
- exenatide injectable suspension
mestranol, exenatide injectable suspension. Other (see comment). Use Caution/Monitor. Comment: Oral contraceptives may decrease hypoglycemic effects of antidiabetics by impairing glucose tolerance. The effect of exenatide to slow gastric emptying may reduce the extent and rate of oral medications that require rapid GI absorption. Advise patients to take oral contraceptives at least 1 hr before exenatide.
- fedratinib
fedratinib will increase the level or effect of mestranol 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 mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- finerenone
mestranol will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor serum potassium during initiation and dosage adjustment of either finererone or weak CYP3A4 inhibitors. Adjust finererone dosage as needed.
- fleroxacin
fleroxacin will decrease the level or effect of mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- flibanserin
mestranol will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increased flibanserin adverse effects may occur if coadministered with multiple weak CYP3A4 inhibitors.
- fluconazole
fluconazole will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- fludrocortisone
fludrocortisone will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- fosamprenavir
fosamprenavir will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
fosamprenavir, mestranol. unspecified interaction mechanism. Use Caution/Monitor. Variable effect on estradiol. Use non-hormonal contraception. - fosaprepitant
fosaprepitant will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- fosfomycin
fosfomycin will decrease the level or effect of mestranol 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
fosphenytoin will decrease the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
mestranol decreases effects of fosphenytoin by decreasing metabolism. Use Caution/Monitor. - gemifloxacin
gemifloxacin will decrease the level or effect of mestranol 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 mestranol 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- griseofulvin
griseofulvin will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- hemin
mestranol decreases effects of hemin by pharmacodynamic antagonism. Use Caution/Monitor. Drugs that increase delta-aminolevulinic acid synthetase may decrease hemin effect.
- hydrocortisone
hydrocortisone will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- iloperidone
iloperidone increases levels of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.
- indinavir
indinavir will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
indinavir will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - isavuconazonium sulfate
mestranol will increase 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 mestranol 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.
- itraconazole
itraconazole will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- ketoconazole
ketoconazole will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- lamotrigine
mestranol decreases levels of lamotrigine by increasing hepatic clearance. Use Caution/Monitor.
- lapatinib
lapatinib will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
lapatinib will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - lemborexant
mestranol will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Lower nightly dose of lemborexant recommended if coadministered with weak CYP3A4 inhibitors. See drug monograph for specific dosage modification.
- levofloxacin
levofloxacin will decrease the level or effect of mestranol 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 mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- linezolid
linezolid will decrease the level or effect of mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- liraglutide
mestranol decreases effects of liraglutide by pharmacodynamic antagonism. Use Caution/Monitor. Oral contraceptives may decrease hypoglycemic effects of antidiabetics by impairing glucose tolerance. Monitor for glycemic control in diabetic patients.
- lixisenatide
lixisenatide will decrease the level or effect of mestranol by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. GLP1 agonists delay gastric emptying, which may affect absorption of concomitantly administered oral medications. Oral contraceptives should be taken at least 1 hr before lixisenatide administration or 11 hr after lixisenatide.
- lomitapide
mestranol increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.
- loratadine
loratadine will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- lumacaftor/ivacaftor
lumacaftor/ivacaftor, mestranol. affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. In vitro studies suggest that lumacaftor may induce and ivacaftor may inhibit CYP2C9 substrates. .
- lumefantrine
lumefantrine will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- maraviroc
mestranol 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- meropenem
meropenem will decrease the level or effect of mestranol 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 mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- methylprednisolone
methylprednisolone will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- metronidazole
metronidazole will decrease the level or effect of mestranol 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. - miconazole vaginal
miconazole vaginal will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- midazolam intranasal
mestranol will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of mild CYP3A4 inhibitors with midazolam intranasal may cause higher midazolam systemic exposure, which may prolong sedation.
- mifepristone
mifepristone decreases effects of mestranol by pharmacodynamic antagonism. Use Caution/Monitor. Backup contraceptive method recommended.
- minocycline
minocycline will decrease the level or effect of mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- mitotane
mitotane decreases levels of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.
- moxifloxacin
moxifloxacin will decrease the level or effect of mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- nafcillin
nafcillin will decrease the level or effect of mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
nafcillin will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. - nefazodone
nefazodone will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- nelfinavir
nelfinavir will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
nelfinavir decreases levels of mestranol by increasing metabolism. Use Caution/Monitor. May result in contraceptive failure. - neomycin PO
neomycin PO will decrease the level or effect of mestranol 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- nicardipine
nicardipine will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- nifedipine
nifedipine will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
nifedipine will decrease the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - nilotinib
nilotinib will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
nilotinib will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - nitisinone
nitisinone will increase the level or effect of mestranol by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. Nitisinone inhibits CYP2C9. Caution if CYP2C9 substrate coadministered, particularly those with a narrow therapeutic index.
- nitrofurantoin
nitrofurantoin will decrease the level or effect of mestranol 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 mestranol 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- oxytetracycline
oxytetracycline will decrease the level or effect of mestranol 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 mestranol 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- phenobarbital
phenobarbital will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
phenobarbital will decrease the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - phenytoin
phenytoin will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
phenytoin will decrease the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
mestranol decreases effects of phenytoin by decreasing metabolism. Use Caution/Monitor. - pivmecillinam
pivmecillinam will decrease the level or effect of mestranol 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- prednisone
prednisone will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- primidone
primidone will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- quercetin
quercetin will decrease the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- quinupristin/dalfopristin
quinupristin/dalfopristin will decrease the level or effect of mestranol 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. - ranolazine
ranolazine will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- ribociclib
ribociclib will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- rifampin
rifampin will decrease the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- rifapentine
rifapentine will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- ritonavir
ritonavir will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
ritonavir will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
ritonavir decreases levels of mestranol by increasing metabolism. Use Caution/Monitor. May result in contraceptive failure; use additional or alternative method. - romidepsin
romidepsin decreases effects of mestranol by receptor binding competition. Use Caution/Monitor.
- roxithromycin
roxithromycin will decrease the level or effect of mestranol 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- secobarbital
secobarbital will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- selegiline transdermal
mestranol increases levels of selegiline transdermal by Other (see comment). Use Caution/Monitor. Comment: Oral contraceptives inhibit the N demethylatin of selegiline.
- siltuximab
siltuximab, mestranol. Other (see comment). Use Caution/Monitor. Comment: CYP450 activity in the liver is down regulated by infection and inflammation stimuli including cytokines (eg, IL-6); inhibition of IL-6 by siltuximab may restore CYP450 enzymatic activity; caution if coadministered with CYP substrates that have a narrow therapeutic index.
- simvastatin
simvastatin will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- sirolimus
sirolimus will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- St John's Wort
St John's Wort will decrease the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- stiripentol
stiripentol, mestranol. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.
- streptomycin
streptomycin will decrease the level or effect of mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- sugammadex
sugammadex decreases levels of mestranol by unspecified interaction mechanism. Use Caution/Monitor. Risk of contraceptive failure.
- sulfadiazine
sulfadiazine will decrease the level or effect of mestranol 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 mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- sulfamethoxypyridazine
sulfamethoxypyridazine decreases effects of mestranol by unspecified interaction mechanism. Use Caution/Monitor.
- sulfisoxazole
sulfisoxazole will decrease the level or effect of mestranol 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 mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- tazemetostat
tazemetostat will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
mestranol will increase 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 mestranol 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 mestranol 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 mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- tetracycline
tetracycline will decrease the level or effect of mestranol 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 mestranol 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 mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- tinidazole
mestranol will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- tobramycin
tobramycin will decrease the level or effect of mestranol 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 mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- topiramate
topiramate will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- tranexamic acid injection
tranexamic acid injection, mestranol. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of thromboembolic disorder.
- trazodone
trazodone will decrease the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- trimethoprim
trimethoprim will decrease the level or effect of mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
- vancomycin
vancomycin will decrease the level or effect of mestranol 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
verapamil will increase the level or effect of mestranol by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. - voriconazole
voriconazole will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- zafirlukast
zafirlukast will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
Minor (58)
- acetazolamide
acetazolamide will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- alfalfa
alfalfa decreases effects of mestranol by pharmacodynamic antagonism. Minor/Significance Unknown. (Theoretical interaction).
- amitriptyline
mestranol, 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
mestranol, amoxapine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
- amphotericin B deoxycholate
amphotericin B deoxycholate decreases effects of mestranol by increasing metabolism. Minor/Significance Unknown. May also cause menstrual irregularities.
- anastrozole
anastrozole will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- androstenedione
androstenedione increases effects of mestranol by pharmacodynamic synergism. Minor/Significance Unknown.
- aprepitant
aprepitant decreases levels of mestranol by increasing metabolism. Minor/Significance Unknown.
- boron
boron increases levels of mestranol by altering metabolism. Minor/Significance Unknown.
- clomipramine
mestranol, clomipramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
- clotrimazole
clotrimazole decreases effects of mestranol by increasing metabolism. Minor/Significance Unknown. May also cause menstrual irregularities.
- cyanocobalamin
mestranol decreases levels of cyanocobalamin by altering metabolism. Minor/Significance Unknown.
- cyclophosphamide
cyclophosphamide will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- desipramine
mestranol, 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
mestranol, 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
mestranol, doxepin. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
- felbamate
felbamate decreases levels of mestranol by unknown mechanism. Minor/Significance Unknown.
- fluconazole
fluconazole decreases effects of mestranol by increasing metabolism. Minor/Significance Unknown. May also cause menstrual irregularities.
- folic acid
mestranol decreases levels of folic acid by altering metabolism. Minor/Significance Unknown.
- fosaprepitant
fosaprepitant decreases levels of mestranol by increasing metabolism. Minor/Significance Unknown.
- green tea
mestranol increases levels of green tea by decreasing elimination. Minor/Significance Unknown. (Caffeine).
- griseofulvin
griseofulvin decreases effects of mestranol by increasing metabolism. Minor/Significance Unknown. May also cause menstrual irregularities.
- imipramine
mestranol, 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 mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- ketoconazole
ketoconazole decreases effects of mestranol by increasing metabolism. Minor/Significance Unknown. May also cause menstrual irregularities.
- L-methylfolate
mestranol decreases levels of L-methylfolate by altering metabolism. Minor/Significance Unknown.
- larotrectinib
larotrectinib will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- levoketoconazole
levoketoconazole decreases effects of mestranol by increasing metabolism. Minor/Significance Unknown. May also cause menstrual irregularities.
- lofepramine
mestranol, 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
mestranol decreases levels of magnesium chloride by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- magnesium citrate
mestranol decreases levels of magnesium citrate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- magnesium hydroxide
mestranol decreases levels of magnesium hydroxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- magnesium oxide
mestranol decreases levels of magnesium oxide by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- magnesium sulfate
mestranol decreases levels of magnesium sulfate by Other (see comment). Minor/Significance Unknown. Comment: Magnesium shifted from blood to tissue storage.
- maprotiline
mestranol, 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
mestranol decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.
- miconazole vaginal
miconazole vaginal decreases effects of mestranol by increasing metabolism. Minor/Significance Unknown. May also cause menstrual irregularities.
- mineral oil
mineral oil decreases levels of mestranol by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.
- mycophenolate
mycophenolate decreases effects of mestranol by unknown mechanism. Minor/Significance Unknown. Clinical significance unclear.
- naratriptan
mestranol increases effects of naratriptan by unspecified interaction mechanism. Minor/Significance Unknown.
- nortriptyline
mestranol, 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 mestranol by pharmacodynamic antagonism. Minor/Significance Unknown.
- pioglitazone
pioglitazone decreases levels of mestranol by unknown mechanism. Minor/Significance Unknown.
- pleurisy root
pleurisy root decreases effects of mestranol by unspecified interaction mechanism. Minor/Significance Unknown. Theoretical interaction.
- posaconazole
posaconazole decreases effects of mestranol by increasing metabolism. Minor/Significance Unknown. May also cause menstrual irregularities.
- protriptyline
mestranol, 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
mestranol decreases levels of pyridoxine by altering metabolism. Minor/Significance Unknown.
- pyridoxine (Antidote)
mestranol decreases levels of pyridoxine (Antidote) by altering metabolism. Minor/Significance Unknown.
- ropinirole
mestranol increases levels of ropinirole by unspecified interaction mechanism. Minor/Significance Unknown.
- rose hips
mestranol decreases levels of rose hips by increasing elimination. Minor/Significance Unknown.
- rosuvastatin
rosuvastatin increases levels of mestranol by unspecified interaction mechanism. Minor/Significance Unknown.
- ruxolitinib
mestranol will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- ruxolitinib topical
mestranol will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- sodium tetradecyl sulfate
sodium tetradecyl sulfate increases toxicity of mestranol by pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of thromboembolic disorder.
- tizanidine
mestranol increases levels of tizanidine by unspecified interaction mechanism. Minor/Significance Unknown.
- trazodone
mestranol, 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
mestranol, trimipramine. Mechanism: unspecified interaction mechanism. Minor/Significance Unknown. Estrogens and progestins may decr tricyclic antidepressant effects, while increasing TCA plasma concentration and adverse effects.
- ursodiol
mestranol decreases effects of ursodiol by pharmacodynamic antagonism. Minor/Significance Unknown.
Adverse Effects
Frequency Not Defined
Common
- Emotional lability
- Headache
- Breast symptoms
- Menstrual cramps
- Abdominal pains
- Nausea
Serious
- Arterial/venous thromboembolism
- Hypertension
- MI
- Cerebral hemorrhage
- Gallbladder disease
- Hepatic adenoma
Warnings
Black Box Warnings
Cigarette smoking & risk of cardiovascular disease
- Cigarette smoking increases risk of serious cardiovascular adverse effects from combination hormonal contraceptive use
- This risk increases w/ age (>35 yr) & with heavy smoking (15 or more cigarettes/day)
- Advise women who use hormonal oral contraceptives not to smoke
Contraindications
Documented hypersensitivity
Active or history of breast cancer
Arterial thromboembolic disease (stroke, MI), thrombophlebitis, DVT/PE, thrombogenic valvular disease
Estrogen-dependent neoplasia
Liver disease, liver tumors
Undiagnosed abnormal vaginal bleeding
Uncontrolled hypertension
Diabetes mellitus with vascular involvement
Jaundice with prior oral contraceptive use
Precautions
Family history of breast cancer and or DVT/PE, current/history of depression, endometriosis, DM, HTN, bone mineral density changes, renal/hepatic impairment, bone metabolic disease, SLE; conditions exacerbated by fluid retention (eg, migraine, asthma, epilepsy)
Discontinue if the following develop jaundice, visual problems (may cause contact lens intolerance), any signs of VTE, migraine with unusual severity, significang blood pressure increase, severe depression, increased risk of thromboembolic complications after surgery
Discontinue 4 week before major surgery or prolonged immobilization
Patients on warfarin, oral anticoagulants (increase in anticoagulant dose may be warranted)
Some studies link OCP use with increased risk of breast cancer, whereas other studies have not shown a change in risk; woman's risk depends on conditions where naturally high hormone levels persist for long periods of time including early onset menstruation before age 12, late onset menopause, after age 55, first child after age 30, nulliparity
Increased risk of cervical cancer with OCP use, however HPV remains as main risk factor for this cancer; evidence suggests long-term use of OCPs, 5 or more years, may be associated with increased risk
Increased risk of liver cancer with OCP use; risk increases with longer duration of OCP use
CDC guidelines recommend waiting at least 3 weeks following vaginal birth or 6 weeks after cesarean section to decrease risk for venous thromboembolism before initiating combined hormonal contraceptives; women with additional risk factors for VTE (besides postpartum) should not use combined hormonal contraceptives (MMWR July 7, 2011)
Pregnancy & Lactation
Pregnancy Category: X
Lactation: small amounts of steroids are excreted in breast milk; estrogens may reduce quality/quantity of milk; may be prudent to use other forms of birth control until full weaning (AAP Committee states compatible w/ nursing)
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
Mestranol: Estrogen; reduces LHRH release from hypothalamus, reduces gonadotropin release from pituitary; increases synthesis of DNA, RNA, and various proteins in target tissues
Norethindrone: Progestin; inhibits secretion of gonadotropins from pituitary; prevents follicular maturation and ovulation, stimulates growth of mammary tissues
Absorption
Bioavailability: 60% (norethindrone)
Peak plasma time: 8 hr (ethinyl estradiol [active metabolite]); 1-2 hr (norethindrone)
Distribution
Protein bound: 80% (ethinyl estradiol [active metabolite]); 61% (norethindrone)
Metabolism
Mestranol: Metabolized to ethinyl estradiol via demethylation
Norethindrone: Liver
Metabolites
- Mestranol metabolized to ethinyl estradiol; ethinyl estradiol further metabolized to estriol, estrone by liver CYP3A4
- Norethindrone: Sulfate and glucuronide metabolites (inactive)
Elimination
Half-life: 4-13 hr (norethindrone)
Excretion
- Ethinyl estradiol (active metabolite): in urine as conjugates, most estrogens are also excreted in the bile and undergo enterohepatic recycling
- Norethindrone: 33-81% urine; 35-43% feces
