Estradiol Interactions

7 DRUG INTERACTIONS The sections below provide information on substances for which data on drug interactions with COCs are available. There is little information available about the clinical effect of most drug interactions that may affect COCs. However, based on the known pharmacokinetic effects of these drugs, clinical strategies to minimize any potential adverse effect on contraceptive effectiveness or safety are suggested. Consult the approved product labeling of all concurrently used drugs to obtain further information about interactions with COCs or the potential for metabolic enzyme or transporter system alterations. No drug-drug interaction studies were conducted with levonorgestrel and ethinyl estradiol tablets. Enzyme inducers (e.g.CYP3A4): May decrease the effectiveness of Iclevia or increase breakthrough bleeding. Counsel patients to use a back-up or alternative method of contraception when enzyme inducers are used with Iclevia. ( 7.1 ) 7.1 Effects of Other Drugs on Combined Oral Contraceptives Substances decreasing the plasma concentrations of COCs and potentially diminishing the efficacy of COCs: Table 5 includes substances that demonstrated an important drug interaction with levonorgestrel and ethinyl estradiol tablets. Table 5: Significant Drug Interactions Involving Substances That Affect COCs a Induction potency of St. John’s wort may vary widely based on preparation. Metabolic Enzyme Inducers Clinical effect Concomitant use of COCs with metabolic enzyme inducers may decrease the plasma concentrations of the estrogen and/or progestin component of COCs. Decreased exposure of the estrogen and/or progestin component of COCs may potentially diminish the effectiveness of COCs and may lead to contraceptive failure or an increase in breakthrough bleeding. Prevention or management Counsel females to use an alternative method of contraception or a backup method when enzyme inducers are used with COCs. Continue backup contraception for 28 days after discontinuing the enzyme inducer to maintain contraceptive reliability. Examples Aprepitant, barbiturates, bosentan, carbamazepine, efavirenz, felbamate, griseofulvin, oxcarbazepine, phenytoin, rifampin, rifabutin, rufinamide, topiramate, products containing St. John’s wort a , and certain protease inhibitors (see separate section on protease inhibitors below). Colesevelam Clinical effect Concomitant use of COCs with colesevelam significantly decreases systemic exposure of ethinyl estradiol [see Clinical Pharmacology (12.3) ] . Decreased exposure of the estrogen component of COCs may potentially reduce contraceptive efficacy or result in an increase in breakthrough bleeding, depending on the strength of ethinyl estradiol in the COC. Prevention or management Administer 4 or more hours apart to attenuate this drug interaction. Substances increasing the systemic exposure of COCs: Co-administration of atorvastatin or rosuvastatin and certain COCs containing ethinyl estradiol (EE) increase AUC values for EE by approximately 20 to 25%. Ascorbic acid and acetaminophen may increase systemic exposure of EE possibly by inhibition of conjugation. CYP3A4 inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice, or ketoconazole may increase systemic exposure of estrogen and/or progestin component of COCs. Human immunodeficiency virus (HIV)/ Hepatitis C virus (HCV) protease inhibitors and non-nucleoside reverse transcriptase inhibitors: Significant decreases in systemic exposure of the estrogen and/or progestin have been noted when COCs are co-administered with some HIV protease inhibitors (e.g., nelfinavir, ritonavir, darunavir/ritonavir, (fos)amprenavir/ritonavir, lopinavir/ritonavir, and tipranavir/ritonavir] or some HCV protease inhibitors (e.g. boceprevir and telaprevir) and some non-nucleosidase reverse transcriptase inhibitors (e.g. nevirapine) In contrast, significant increases in systemic exposure of the estrogen and/or progestin have been noted when COCs are co-administered with certain other HIV protease inhibitors (e.g. indinavir and atazanavir/ritonavir) and with other non-nucleoside reverse transcriptase inhibitors (e.g. etravirine). 7.2 Effects of Combined Oral Contraceptives on Other Drugs Table 6 provides significant drug interaction information for drugs co-administered with levonorgestrel and ethinyl estradiol tablets. Table 6: Significant Drug Interaction Information for Drugs Co-Administered With COCs Lamotrigine Clinical effect Concomitant use of COCs with lamotrigine may significantly decrease systemic exposure of lamotrigine due to induction of lamotrigine glucuronidation [See Clinical Pharmacology (12.3) ] . Decreased systemic exposure of lamotrigine may reduce seizure control. Prevention or management Dose adjustment may be necessary. Consult the approved product labeling for lamotrigine. Thyroid Hormone Replacement Therapy or Corticosteroid Replacement Therapy Clinical effect Concomitant use of COCs with thyroid hormone replacement therapy or corticosteroid replacement therapy may increase systemic exposure of thyroid-binding and cortisol-binding globulin [see Warnings and Precautions (5.12) ] . Prevention or management The dose of replacement thyroid hormone or cortisol therapy may need to be increased. Consult the approved product labeling for the therapy in use [see Warnings and Precautions (5.12) ] . Other Drugs Clinical effect Concomitant use of COCs may decrease systemic exposure of acetaminophen, morphine, salicylic acid, and temazepam. Concomitant use with ethinyl estradiol-containing COCs may increase systemic exposure of other drugs (e.g., cyclosporine, prednisolone, theophylline, tizanidine, and voriconazole). Prevention or management The dosage of drugs that can be affected by this interaction may need to be increased. Consult the approved product labeling for the concomitantly used drug. 7.3 Concomitant Use with Hepatitis C Virus (HCV) Combination Therapy-Liver Enzyme Elevation Co-administration of Iclevia with HCV drug combinations containing ombitasvir/paritaprevir/ritonavir, with or without dasabuvir is contraindicated due to potential for ALT elevations [see Warning and Precautions (5.3) ]. Co-administration of Iclevia and glecaprevir/pibrentasvir is not recommended due to potential for ALT elevations. 7.4 Effect on Laboratory Tests The use of COCs may influence the results of certain laboratory tests, such as coagulation factors, lipids, glucose tolerance, and binding proteins.

7 DRUG INTERACTIONS Consult the labeling of concurrently used drugs to obtain further information about interactions with hormonal contraceptives or the potential for enzyme alterations. No drug-drug interaction studies were conducted with Sprintec. Drugs or herbal products that induce certain enzymes including CYP3A4, may decrease the effectiveness of COCs or increase breakthrough bleeding. Counsel patients to use a back-up or alternative method of contraception when enzyme inducers are used with COCs. ( 7.1 ) 7.1 Effects of Other Drugs on Combined Oral Contraceptives Substances decreasing the plasma concentrations of COCs Drugs or herbal products that induce certain enzymes, including cytochrome P450 3A4 (CYP3A4), may decrease the plasma concentrations of COCs and potentially diminish the effectiveness of COCs or increase breakthrough bleeding. Some drugs or herbal products that may decrease the effectiveness of hormonal contraceptives include phenytoin, barbiturates, carbamazepine, bosentan, felbamate, griseofulvin, oxcarbazepine, rifampicin, topiramate, rifabutin, rufinamide, aprepitant, and products containing St. John’s wort. Interactions between hormonal contraceptives and other drugs may lead to breakthrough bleeding and/or contraceptive failure. Counsel women to use an alternative method of contraception or a back-up method when enzyme inducers are used with COCs, and to continue back-up contraception for 28 days after discontinuing the enzyme inducer to ensure contraceptive reliability. Colesevelam : Colesevelam, a bile acid sequestrant, given together with a COC, has been shown to significantly decrease the AUC of EE. The drug interaction between the contraceptive and colesevelam was decreased when the two drug products were given 4 hours apart. Substances increasing the plasma concentrations of COCs Coadministration of atorvastatin or rosuvastatin and certain COCs containing ethinyl estradiol (EE) increase AUC values for EE by approximately 20 to 25%. Ascorbic acid and acetaminophen may increase plasma EE concentrations, possibly by inhibition of conjugation. CYP3A4 inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice, or ketoconazole may increase plasma hormone concentrations. Human immunodeficiency virus (HIV)/Hepatitis C virus (HCV) protease inhibitors, non-nucleoside reverse transcriptase inhibitors, and HIV/AIDS medications containing strong inhibitors or inducers of CYP3A Significant changes (increase or decrease) in the plasma concentrations of estrogen and/or progestin have been noted in some cases of coadministration with HIV protease inhibitors (decrease [e.g., nelfinavir, ritonavir, darunavir/ritonavir, (fos)amprenavir/ritonavir, lopinavir/ritonavir, and tipranavir/ritonavir] or increase [e.g., indinavir and atazanavir/ritonavir])/HCV protease inhibitors (decrease [e.g., boceprevir and telaprevir]) or with non-nucleoside reverse transcriptase inhibitors (decrease [e.g., nevirapine] or increase [e.g., etravirine]) or with HIV/AIDS medications containing strong inhibitors (e.g., cobicistat and ritonavir) or inducers of CYP3A. 7.2 Effects of Combined Oral Contraceptives on Other Drugs COCs containing EE may inhibit the metabolism of other compounds (e.g., cyclosporine, prednisolone, theophylline, tizanidine, and voriconazole) and increase their plasma concentrations. COCs have been shown to decrease plasma concentrations of acetaminophen, clofibric acid, morphine, salicylic acid, temazepam and lamotrigine. Significant decrease in plasma concentration of lamotrigine has been shown, likely due to induction of lamotrigine glucuronidation. This may reduce seizure control; therefore, dosage adjustments of lamotrigine may be necessary. Women on thyroid hormone replacement therapy may need increased doses of thyroid hormone because the serum concentration of thyroid-binding globulin increases with use of COCs. 7.3 Interference with Laboratory Tests The use of contraceptive steroids may influence the results of certain laboratory tests, such as coagulation factors, lipids, glucose tolerance, and binding proteins. 7.4 Concomitant Use with HCV Combination Therapy – Liver Enzyme Elevation Do not coadminister Sprintec with HCV drug combinations containing ombitasvir/paritaprevir/ritonavir, with or without dasabuvir, due to potential for ALT elevations [see Warnings and Precautions ( 5.3 )].

D. Drug-Laboratory Test Interactions 1. Accelerated prothrombin time, partial thromboplastin time, and platelet aggregation time; increased platelet count; increased factors II, VII antigen, VIII antigen, VIII coagulant activity, IX, X, XII, VII-X complex, II-VII-X complex, and beta-thromboglobulin; decreased levels of anti-factor Xa and antithrombin III, decreased antithrombin III activity; increased levels of fibrinogen and fibrinogen activity; increased plasminogen antigen and activity. 2. Increased thyroid-binding globulin (TBG) leading to increased circulating total thyroid hormone levels, as measured by protein-bound iodine (PBI), T 4 levels (by column or by radioimmunoassay) or T 3 levels by radioimmunoassay. T 3 resin uptake is decreased, reflecting the elevated TBG. Free T 4 and free T 3 concentrations are unaltered. Women on thyroid replacement therapy may require higher dose of thyroid hormone. 3. Other binding proteins may be elevated in serum, i.e., corticosteroid binding globulin (CBG), sex hormone-binding globulin (SHBG), leading to increased total circulating corticosteroids and sex steroids, respectively. Free hormone concentrations, such as testosterone and estradiol, may be decreased. Other plasma proteins may be increased (angiotensinogen/renin substrate, alpha-1-antitrypsin, ceruloplasmin). 4. Increased plasma high-density lipoprotein (HDL) and HDL 2 cholesterol subfraction concentrations, reduced low-density lipoprotein (LDL) cholesterol concentration, increased triglycerides levels. 5. Impaired glucose tolerance.

No interactions listed

No interactions listed

Drug Interactions In vitro studies were conducted to investigate the potential of gabapentin to inhibit the major cytochrome P450 enzymes (CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4) that mediate drug and xenobiotic metabolism using isoform selective marker substrates and human liver microsomal preparations. Only at the highest concentration tested (171 mcg/mL; 1 mM) was a slight degree of inhibition (14% to 30%) of isoform CYP2A6 observed. No inhibition of any of the other isoforms tested was observed at gabapentin concentrations up to 171 mcg/mL (approximately 15 times the C max at 3600 mg/day). Gabapentin is not appreciably metabolized nor does it interfere with the metabolism of commonly coadministered antiepileptic drugs. The drug interaction data described in this section were obtained from studies involving healthy adults and adult patients with epilepsy.

7 DRUG INTERACTIONS Avoid concomitant use with aliskiren in patients with estimated glomerular filtration rate (eGFR) less than 60. ( 7.1 ) Potassium-sparing diuretics: May lead to increased serum potassium. ( 7.2 ) Nonsteroidal Anti-Inflammatory Drugs (NSAIDs): May lead to increased risk of renal impairment. ( 7.3 ) Lithium: Increased risk of lithium toxicity. ( 7.4 ) 7.1 Dual Blockade of the Renin-Angiotensin-Aldosterone System Concomitant use of ENTRESTO with an ACE inhibitor is contraindicated because of the increased risk of angioedema [see Contraindications (4)] . Avoid use of ENTRESTO with an ARB, because ENTRESTO contains the angiotensin II receptor blocker valsartan. The concomitant use of ENTRESTO with aliskiren is contraindicated in patients with diabetes [see Contraindications (4)] . Avoid use with aliskiren in patients with renal impairment (eGFR less than 60 mL/min/1.73 m 2 ). 7.2 Potassium-Sparing Diuretics As with other drugs that block angiotensin II or its effects, concomitant use of potassium-sparing diuretics (e.g., spironolactone, triamterene, amiloride), potassium supplements, or salt substitutes containing potassium may lead to increases in serum potassium [see Warnings and Precautions (5.5)] . 7.3 Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) Including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors) In patients who are elderly, volume-depleted (including those on diuretic therapy), or with compromised renal function, concomitant use of NSAIDs, including COX-2 inhibitors, with ENTRESTO may result in worsening of renal function, including possible acute renal failure. These effects are usually reversible. Monitor renal function periodically. 7.4 Lithium Increases in serum lithium concentrations and lithium toxicity have been reported during concomitant administration of lithium with angiotensin II receptor antagonists. Monitor serum lithium levels during concomitant use with ENTRESTO.

Drug Interactions Vitamin A: Because of the relationship of Amnesteem to vitamin A, patients should be advised against taking vitamin supplements containing vitamin A to avoid additive toxic effects. Tetracyclines: Concomitant treatment with Amnesteem and tetracyclines should be avoided because Amnesteem use has been associated with a number of cases of pseudotumor cerebri (benign intracranial hypertension), some of which involved concomitant use of tetracyclines. Micro-dosed Progesterone Preparations: Micro-dosed progesterone preparations (“minipills” that do not contain an estrogen) may be an inadequate method of contraception during Amnesteem therapy. Although other hormonal contraceptives are highly effective, there have been reports of pregnancy from female patients who have used combined oral contraceptives, as well as transdermal patch/injectable/implantable/vaginal ring hormonal birth control products. These reports are more frequent for female patients who use only a single method of contraception. It is not known if hormonal contraceptives differ in their effectiveness when used with Amnesteem. Therefore, it is critically important for female patients of childbearing potential to select and commit to use two forms of effective contraception simultaneously, at least one of which must be a primary form (see PRECAUTIONS ). Norethindrone/ethinyl estradiol: In a study of 31 premenopausal female patients with severe recalcitrant nodular acne receiving OrthoNovum ® 7/7/7 Tablets as an oral contraceptive agent, Amnesteem at the recommended dose of 1 mg/kg/day, did not induce clinically relevant changes in the pharmacokinetics of ethinyl estradiol and norethindrone and in the serum levels of progesterone, follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Prescribers are advised to consult the package insert of medication administered concomitantly with hormonal contraceptives, since some medications may decrease the effectiveness of these birth control products. St. John’s Wort: Amnesteem use is associated with depression in some patients (see WARNINGS: Psychiatric Disorders and ADVERSE REACTIONS: Psychiatric ). Patients should be prospectively cautioned not to self-medicate with the herbal supplement St. John’s Wort because a possible interaction has been suggested with hormonal contraceptives based on reports of breakthrough bleeding on oral contraceptives shortly after starting St. John's Wort. Pregnancies have been reported by users of combined hormonal contraceptives who also used some form of St. John's Wort. Phenytoin: Amnesteem has not been shown to alter the pharmacokinetics of phenytoin in a study in seven healthy volunteers. These results are consistent with the in vitro finding that neither isotretinoin nor its metabolites induce or inhibit the activity of the CYP 2C9 human hepatic P450 enzyme. Phenytoin is known to cause osteomalacia. No formal clinical studies have been conducted to assess if there is an interactive effect on bone loss between phenytoin and Amnesteem. Therefore, caution should be exercised when using these drugs together. Systemic Corticosteroids: Systemic corticosteroids are known to cause osteoporosis. No formal clinical studies have been conducted to assess if there is an interactive effect on bone loss between systemic corticosteroids and Amnesteem. Therefore, caution should be exercised when using these drugs together.

7 DRUG INTERACTIONS Probenicid decreases renal tubular secretion of amoxicillin which may result in increased blood levels of amoxicillin. ( 7.1 ) Concomitant use of Amoxicillin and oral anticoagulants may increase the prolongation of prothrombin time. ( 7.2 ) Coadministration with allopurinol increases the risk of rash. ( 7.3 ) Amoxicillin may reduce the efficacy of oral contraceptives. ( 7.4 ) 7.1 Probenecid Probenecid decreases the renal tubular secretion of amoxicillin. Concurrent use of amoxicillin and probenecid may result in increased and prolonged blood levels of amoxicillin. 7.2 Oral Anticoagulants Abnormal prolongation of prothrombin time (increased international normalized ratio [INR]) has been reported in patients receiving amoxicillin and oral anticoagulants. Appropriate monitoring should be undertaken when anticoagulants are prescribed concurrently. Adjustments in the dose of oral anticoagulants may be necessary to maintain the desired level of anticoagulation. 7.3 Allopurinol The concurrent administration of allopurinol and amoxicillin increases the incidence of rashes in patients receiving both drugs as compared to patients receiving amoxicillin alone. It is not known whether this potentiation of amoxicillin rashes is due to allopurinol or the hyperuricemia present in these patients. 7.4 Oral Contraceptives AMOXICILLIN may affect the gut flora, leading to lower estrogen reabsorption and reduced efficacy of combined oral estrogen/progesterone contraceptives. 7.5 Other Antibacterials Chloramphenicol, macrolides, sulfonamides, and tetracyclines may interfere with the bactericidal effects of penicillin. This has been demonstrated in vitro; however, the clinical significance of this interaction is not well documented. 7.6 Effects on Laboratory Tests High urine concentrations of ampicillin may result in false-positive reactions when testing for the presence of glucose in urine using CLINITEST ® , Benedict’s Solution, or Fehling’s Solution. Since this effect may also occur with amoxicillin, it is recommended that glucose tests based on enzymatic glucose oxidase reactions (such as CLINISTIX ® ) be used. Following administration of ampicillin or amoxicillin to pregnant women, a transient decrease in plasma concentration of total conjugated estriol, estriol-glucuronide, conjugated estrone, and estradiol has been noted.

7 DRUG INTERACTIONS Table 2 includes drugs with clinically important drug interactions when administered concomitantly with ACIPHEX delayed-release tablets and instructions for preventing or managing them. Consult the labeling of concomitantly used drugs to obtain further information about interactions with PPIs. Table 2: Clinically Relevant Interactions Affecting Drugs Co-Administered with ACIPHEX Delayed-Release Tablets Antiretrovirals Clinical Impact: The effect of PPI on antiretroviral drugs is variable. The clinical importance and the mechanisms behind these interactions are not always known. Decreased exposure of some antiretroviral drugs (e.g., rilpivirine, atazanavir, and nelfinavir) when used concomitantly with rabeprazole may reduce antiviral effect and promote the development of drug resistance. Increased exposure of other antiretroviral drugs (e.g., saquinavir) when used concomitantly with rabeprazole may increase toxicity . There are other antiretroviral drugs which do not result in clinically relevant interactions with rabeprazole. Intervention: Rilpivirine -containing products : Concomitant use with ACIPHEX delayed-release tablets is contraindicated [see Contraindications (4) ] . See prescribing information. Atazanavir : See prescribing information for atazanavir for dosing information. Nelfinavir : Avoid concomitant use with ACIPHEX delayed-release tablets. See prescribing information for nelfinavir. Saquinavir: See the prescribing information for saquinavir and monitor for potential saquinavir toxicities. Other antiretrovirals : See prescribing information. Warfarin Clinical Impact: Increased INR and prothrombin time in patients receiving PPIs, including rabeprazole, and warfarin concomitantly. Increases in INR and prothrombin time may lead to abnormal bleeding and even death [see Warnings and Precautions (5.2) ] . Intervention: Monitor INR and prothrombin time. Dose adjustment of warfarin may be needed to maintain target INR range. See prescribing information for warfarin. Methotrexate Clinical Impact: Concomitant use of rabeprazole with methotrexate (primarily at high dose) may elevate and prolong serum levels of methotrexate and/or its metabolite hydroxymethotrexate, possibly leading to methotrexate toxicities. No formal drug interaction studies of methotrexate with PPIs have been conducted [see Warnings and Precautions (5.8) ]. Intervention: A temporary withdrawal of ACIPHEX delayed-release tablets may be considered in some patients receiving high dose methotrexate administration. Digoxin Clinical Impact: Potential for increased exposure of digoxin [ see Clinical Pharmacology (12.3) ] . Intervention: Monitor digoxin concentrations. Dose adjustment of digoxin may be needed to maintain therapeutic drug concentrations. See prescribing information for digoxin. Drugs Dependent on Gastric pH for Absorption (e.g., ir on salts, erlotinib, dasatinib, nilotinib, mycophenol ate mofetil, ketoconazole , itraconazole ) Clinical Impact: Rabeprazole can reduce the absorption of drugs due to its effect on reducing intragastric acidity. Intervention: Mycophenolate mofetil (MMF): Co-administration of PPIs in healthy subjects and in transplant patients receiving MMF has been reported to reduce the exposure to the active metabolite, mycophenolic acid (MPA), possibly due to a decrease in MMF solubility at an increased gastric pH. The clinical relevance of reduced MPA exposure on organ rejection has not been established in transplant patients receiving PPIs and MMF. Use ACIPHEX delayed-release tablets with caution in transplant patients receiving MMF. See the prescribing information for other drugs dependent on gastric pH for absorption. Combination Therapy with Clarithromycin and Amoxicillin Clinical Impact: Concomitant administration of clarithromycin with other drugs can lead to serious adverse reactions, including potentially fatal arrhythmias, and are contraindicated . Amoxicillin also has drug interactions. Intervention: See Contraindications and Warnings and Precautions in prescribing information for clarithromycin. See Drug Interactions in prescribing information for amoxicillin. See full prescribing information for a list of clinically important drug interactions ( 7 ).