Drug Interaction Report
1 drug interaction and 28 additional warnings found for the following 2 drugs:
- felbamate
- Opill (norgestrel)
Drug interactions
Major drug interactions
Major:norgestrel felbamate
Applies to: Opill (norgestrel), felbamate
Felbamate may reduce the blood levels and effects of norgestrel.
If you are using low-dose oral contraceptives, you may have an increased risk of breakthrough bleeding and unintended pregnancy. You should discuss the use of alternative or additional methods of birth control with your healthcare provider.
If you take hormone replacement for menopause, notify your doctor if your medication is no longer controlling your symptoms or you experience abnormal bleeding.
You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications.
It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
Food/lifestyle interactions
Moderate food/lifestyle interactions
Moderate:Food/Lifestyle norgestrel
Applies to: Opill (norgestrel)
Grapefruit juice may increase the blood levels of certain medications such as norgestrel.
You may want to limit your consumption of grapefruit and grapefruit juice during treatment with norgestrel. However, if you have been regularly consuming grapefruit or grapefruit juice with the medication, then it is advisable for you to talk with your doctor before changing the amounts of these products in your diet, as this may alter the effects of your medication.
Contact your doctor if your condition changes or you experience increased side effects.
Orange juice is not expected to interact.
Moderate:Food/Lifestyle felbamate
Applies to: felbamate
Alcohol can increase the nervous system side effects of felbamate such as:
- dizziness
- drowsiness
- difficulty concentrating
Some people may also experience impairment in thinking and judgment.
You should avoid or limit the use of alcohol while being treated with felbamate.
Do not use more than the recommended dose of felbamate, and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you.
Talk to your doctor or pharmacist if you have any questions or concerns.
Minor food/lifestyle interactions
Minor:Alcohol (Ethanol) norgestrel
Applies to: Opill (norgestrel)
Information for this minor interaction is available on the professional version.
Disease interactions
25 potential interactionsApplies to: 22 conditions, including High Blood Pressure, High Cholesterol, Depression, Migraine, and Weight Loss.
Anemia
Major:felbamate
Felbamate has a major potential interaction with Anemia.
The use of felbamate is contraindicated in patients with bone marrow suppression or a current or prior history of blood dyscrasias. A marked increase in the incidence of aplastic anemia has been associated with the use of felbamate, reportedly exceeding 100 times the incidence observed in the general population (2 to 5 per million persons per year). In the few cases that have been reported in felbamate patients, the onset of clinical manifestations of aplastic anemia ranged from 5 to 30 weeks. However, the injury to bone marrow stem cells that is believed to be ultimately responsible for the anemia may occur much earlier. Currently, it is not known whether the risk is related to dose, duration of exposure, and/or concomitant use of other antiepileptic or myelotoxic drugs. Expert hematologic consultation should be available for all patients treated with felbamate. Since aplastic anemia typically develops without premonitory clinical or laboratory signs, it should be borne in mind that routine blood testing may not be reliably used to prevent development of the syndrome. However, in some cases, it may allow the detection of hematologic changes before the condition is full-blown. Felbamate therapy should be withdrawn if evidence of bone marrow depression is observed. Patients who are discontinued from the drug may remain at risk for developing anemia for a variable and unknown period afterwards and should be monitored accordingly.
Asthma
Moderate:Opill
The norgestrel in Opill has a moderate potential interaction with Asthma.
Estrogens and progestogens may cause fluid retention, particularly when given in high dosages or for prolonged periods. Therapy with these agents should be administered cautiously in patients who have preexisting problems with excess fluid. In addition, patients with conditions that may be adversely affected by fluid accumulation, such as asthma, epilepsy, migraine, and cardiovascular or renal dysfunction, should be observed for exacerbation of their condition during estrogen and/or progestogen therapy.
Bone Marrow Depression/Low Blood Counts
Major:felbamate
Felbamate has a major potential interaction with Bone Marrow Depression/Low Blood Counts.
The use of felbamate is contraindicated in patients with bone marrow suppression or a current or prior history of blood dyscrasias. A marked increase in the incidence of aplastic anemia has been associated with the use of felbamate, reportedly exceeding 100 times the incidence observed in the general population (2 to 5 per million persons per year). In the few cases that have been reported in felbamate patients, the onset of clinical manifestations of aplastic anemia ranged from 5 to 30 weeks. However, the injury to bone marrow stem cells that is believed to be ultimately responsible for the anemia may occur much earlier. Currently, it is not known whether the risk is related to dose, duration of exposure, and/or concomitant use of other antiepileptic or myelotoxic drugs. Expert hematologic consultation should be available for all patients treated with felbamate. Since aplastic anemia typically develops without premonitory clinical or laboratory signs, it should be borne in mind that routine blood testing may not be reliably used to prevent development of the syndrome. However, in some cases, it may allow the detection of hematologic changes before the condition is full-blown. Felbamate therapy should be withdrawn if evidence of bone marrow depression is observed. Patients who are discontinued from the drug may remain at risk for developing anemia for a variable and unknown period afterwards and should be monitored accordingly.
Breast Cancer
Major:Opill
The norgestrel in Opill has a major potential interaction with Breast Cancer.
The use of progestogens is considered by manufacturers to be contraindicated in patients with existing or suspected malignancy of the breast. Some supportive data are available for medroxyprogesterone. Specifically, medroxyprogesterone treatment may be associated with breast cancer, primarily when the drug is administered intramuscularly. A pooled analysis of two case-control studies, one from the World Health Organization and the other from New Zealand, revealed a small overall relative risk of breast cancer in women who have ever used intramuscular medroxyprogesterone acetate. The relative risk was higher in the subgroup of women who had initiated therapy within the previous 5 years. Thus, an increased risk (approximately 2-fold) is associated with intramuscular medroxyprogesterone use in the first 5 years. A more recent U.S. study also found a statistically significant increase in breast cancer risk among recent users (defined as last use within the past five years) who used depo-medroxyprogesterone acetate for 12 months or longer.
Cerebral Vascular Disorder
Major:Opill
The norgestrel in Opill has a major potential interaction with Cerebral Vascular Disorder.
The use of progestogens, in general, is considered by manufacturers to be contraindicated in patients with active thrombophlebitis, cerebrovascular disease, or a current or past history of thromboembolic disorders. While the role of progestogens in the development of thromboembolic events associated with hormonal therapy is often unclear and thought to be secondary to that of estrogens, it may not be insignificant. Medroxyprogesterone, a common progestational agent, has been shown to produce a hypercoagulable state in high dosages. Whether or not this effect contributes to the development of thrombotic events is unknown. However, thrombophlebitis and pulmonary embolism have been reported with megestrol, an antineoplastic and progestational agent. In addition, an increased risk of nonfatal venous thrombosis has been associated with oral contraceptive combinations containing desogestrel or gestodene relative to those that contain other progestins (e.g., levonorgestrel, norethindrone), suggesting some degree of hemostatic effect by progestogens.
Depression
Moderate:felbamate
Felbamate has a moderate potential interaction with Depression.
Antiepileptic drugs (AEDs) have been associated with an increased risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Pooled analyses of 199 placebo-controlled clinical studies involving the use of 11 different AEDs showed that patients receiving AEDs had approximately twice the risk of suicidal thinking or behavior compared to patients receiving placebo. AEDs should be administered cautiously in patients with depression or other psychiatric disorders; phentermine-topiramate should be avoided in patients with history of suicidal attempts or active suicidal ideation. The risk of suicidal thoughts and behavior should be carefully assessed against the risk of untreated illness, bearing in mind that epilepsy and many other conditions for which AEDs are prescribed are themselves associated with morbidity and mortality and an increased risk of suicidal thoughts and behavior. Patients, caregivers, and families should be alert to the emergence or worsening of signs and symptoms of depression, any unusual changes in mood or behavior, or the emergence of suicidal thoughts or behavior. If patients have symptoms of suicidal ideation or behavior, a dosage reduction or treatment discontinuation should be considered.
Moderate:Opill
The norgestrel in Opill has a moderate potential interaction with Depression.
The use of oral contraceptives has been associated with an increased incidence of depression. It is uncertain whether this effect is related to the estrogenic or the progestogenic component of the contraceptive, although excess progesterone activity is associated with depression. Patients with a history of depression receiving estrogen and/or progestogen therapy should be followed closely. The manufacturer of medroxyprogesterone recommends monitoring patients who have a history of depression and to not re- administer medroxyprogesterone if depression recurs.
Diabetes Mellitus
Moderate:Opill
The norgestrel in Opill has a moderate potential interaction with Diabetes Mellitus.
Impaired glucose tolerance has been observed in some patients administered oral contraceptives and appears to be related primarily to the estrogen dose. However, progestogens can increase insulin secretion and produce insulin resistance to varying degrees, depending on the agent. Caution and close monitoring are recommended in patients with diabetes mellitus during therapy with estrogens and/or progestogens, and adjustments made accordingly in their antidiabetic regimen.
Fluid Retention
Moderate:Opill
The norgestrel in Opill has a moderate potential interaction with Fluid Retention.
Estrogens and progestogens may cause fluid retention, particularly when given in high dosages or for prolonged periods. Therapy with these agents should be administered cautiously in patients who have preexisting problems with excess fluid. In addition, patients with conditions that may be adversely affected by fluid accumulation, such as asthma, epilepsy, migraine, and cardiovascular or renal dysfunction, should be observed for exacerbation of their condition during estrogen and/or progestogen therapy.
Heart Failure
Moderate:Opill
The norgestrel in Opill has a moderate potential interaction with Heart Failure.
Estrogens and progestogens may cause fluid retention, particularly when given in high dosages or for prolonged periods. Therapy with these agents should be administered cautiously in patients who have preexisting problems with excess fluid. In addition, patients with conditions that may be adversely affected by fluid accumulation, such as asthma, epilepsy, migraine, and cardiovascular or renal dysfunction, should be observed for exacerbation of their condition during estrogen and/or progestogen therapy.
Hepatic Tumor
Major:Opill
The norgestrel in Opill has a major potential interaction with Hepatic Tumor.
The use of oral contraceptives is contraindicated in patients with liver tumors. An increased risk of benign hepatic adenomas and hepatocellular carcinomas has been associated with long-term, oral estrogen- progestin contraceptive use of at least 4 years and 8 years, respectively. Although these tumors are rare and have not been reported with other types of estrogen or progestogen therapies, any preparation containing estrogens and/or progestogens should probably be avoided in patients with existing tumors of the liver. Hepatic hemangiomas and nodular hyperplasia of the liver have been reported with isolated estrogen therapy.
High Blood Pressure
Moderate:Opill
The norgestrel in Opill has a moderate potential interaction with High Blood Pressure.
Estrogens and progestogens may cause fluid retention, particularly when given in high dosages or for prolonged periods. Therapy with these agents should be administered cautiously in patients who have preexisting problems with excess fluid. In addition, patients with conditions that may be adversely affected by fluid accumulation, such as asthma, epilepsy, migraine, and cardiovascular or renal dysfunction, should be observed for exacerbation of their condition during estrogen and/or progestogen therapy.
High Cholesterol
Moderate:Opill
The norgestrel in Opill has a moderate potential interaction with High Cholesterol.
Some progestogenic agents may elevate plasma LDL levels and/or lower HDL levels, although data have been inconsistent. Patients with preexisting hyperlipidemia may require closer monitoring during progestogen therapy, and adjustments made accordingly in their lipid-lowering regimen.
History, Thrombotic/Thromboembolic Disorder
Major:Opill
The norgestrel in Opill has a major potential interaction with History, Thrombotic/Thromboembolic Disorder.
The use of progestogens, in general, is considered by manufacturers to be contraindicated in patients with active thrombophlebitis, cerebrovascular disease, or a current or past history of thromboembolic disorders. While the role of progestogens in the development of thromboembolic events associated with hormonal therapy is often unclear and thought to be secondary to that of estrogens, it may not be insignificant. Medroxyprogesterone, a common progestational agent, has been shown to produce a hypercoagulable state in high dosages. Whether or not this effect contributes to the development of thrombotic events is unknown. However, thrombophlebitis and pulmonary embolism have been reported with megestrol, an antineoplastic and progestational agent. In addition, an increased risk of nonfatal venous thrombosis has been associated with oral contraceptive combinations containing desogestrel or gestodene relative to those that contain other progestins (e.g., levonorgestrel, norethindrone), suggesting some degree of hemostatic effect by progestogens.
History of Blood Dyscrasias
Major:felbamate
Felbamate has a major potential interaction with History of Blood Dyscrasias.
The use of felbamate is contraindicated in patients with bone marrow suppression or a current or prior history of blood dyscrasias. A marked increase in the incidence of aplastic anemia has been associated with the use of felbamate, reportedly exceeding 100 times the incidence observed in the general population (2 to 5 per million persons per year). In the few cases that have been reported in felbamate patients, the onset of clinical manifestations of aplastic anemia ranged from 5 to 30 weeks. However, the injury to bone marrow stem cells that is believed to be ultimately responsible for the anemia may occur much earlier. Currently, it is not known whether the risk is related to dose, duration of exposure, and/or concomitant use of other antiepileptic or myelotoxic drugs. Expert hematologic consultation should be available for all patients treated with felbamate. Since aplastic anemia typically develops without premonitory clinical or laboratory signs, it should be borne in mind that routine blood testing may not be reliably used to prevent development of the syndrome. However, in some cases, it may allow the detection of hematologic changes before the condition is full-blown. Felbamate therapy should be withdrawn if evidence of bone marrow depression is observed. Patients who are discontinued from the drug may remain at risk for developing anemia for a variable and unknown period afterwards and should be monitored accordingly.
Liver Disease
Major:felbamate
Felbamate has a major potential interaction with Liver Disease.
The use of felbamate is contraindicated in patients with a history of hepatic impairment. A marked increase in the incidence of hepatic failure, some resulting in fatality, has been associated with the use of felbamate relative to that expected in the general population (approximately 2000 cases per year). Currently, it is not known whether the risk is related to dose, duration of exposure, and/or concomitant use of other antiepileptic or hepatotoxic drugs. All patients treated with felbamate should have serum transaminase and bilirubin levels checked prior to initiating therapy and at 1- to 2-week intervals while treatment continues. Felbamate therapy should be withdrawn if abnormal liver function tests occur.
Major:Opill
The norgestrel in Opill has a major potential interaction with Liver Disease.
The use of progestogens, in general, is contraindicated in patients with impaired hepatic function or liver disease. There are little or no data concerning the pharmacokinetic disposition of the different progestogens in patients with hepatic disease. However, most hormones, including progestational hormones, are known to be extensively metabolized by the liver. Medroxyprogesterone should not be used by women with significant liver disease and should be discontinued if jaundice or disturbances of liver function occur.
Migraine
Moderate:Opill
The norgestrel in Opill has a moderate potential interaction with Migraine.
Estrogens and progestogens may cause fluid retention, particularly when given in high dosages or for prolonged periods. Therapy with these agents should be administered cautiously in patients who have preexisting problems with excess fluid. In addition, patients with conditions that may be adversely affected by fluid accumulation, such as asthma, epilepsy, migraine, and cardiovascular or renal dysfunction, should be observed for exacerbation of their condition during estrogen and/or progestogen therapy.
Psychosis
Moderate:felbamate
Felbamate has a moderate potential interaction with Psychosis.
Antiepileptic drugs (AEDs) have been associated with an increased risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Pooled analyses of 199 placebo-controlled clinical studies involving the use of 11 different AEDs showed that patients receiving AEDs had approximately twice the risk of suicidal thinking or behavior compared to patients receiving placebo. AEDs should be administered cautiously in patients with depression or other psychiatric disorders; phentermine-topiramate should be avoided in patients with history of suicidal attempts or active suicidal ideation. The risk of suicidal thoughts and behavior should be carefully assessed against the risk of untreated illness, bearing in mind that epilepsy and many other conditions for which AEDs are prescribed are themselves associated with morbidity and mortality and an increased risk of suicidal thoughts and behavior. Patients, caregivers, and families should be alert to the emergence or worsening of signs and symptoms of depression, any unusual changes in mood or behavior, or the emergence of suicidal thoughts or behavior. If patients have symptoms of suicidal ideation or behavior, a dosage reduction or treatment discontinuation should be considered.
Renal Dysfunction
Major:felbamate
Felbamate has a major potential interaction with Renal Dysfunction.
Felbamate is partially eliminated by the kidney as unchanged drug (approximately 40% to 50% of absorbed dose). The plasma clearance of felbamate may be decreased and the half-life prolonged in patients with impaired renal function. Therapy with felbamate should be administered cautiously in patients with renal impairment.
Moderate:Opill
The norgestrel in Opill has a moderate potential interaction with Renal Dysfunction.
Estrogens and progestogens may cause fluid retention, particularly when given in high dosages or for prolonged periods. Therapy with these agents should be administered cautiously in patients who have preexisting problems with excess fluid. In addition, patients with conditions that may be adversely affected by fluid accumulation, such as asthma, epilepsy, migraine, and cardiovascular or renal dysfunction, should be observed for exacerbation of their condition during estrogen and/or progestogen therapy.
Seizures
Moderate:Opill
The norgestrel in Opill has a moderate potential interaction with Seizures.
Estrogens and progestogens may cause fluid retention, particularly when given in high dosages or for prolonged periods. Therapy with these agents should be administered cautiously in patients who have preexisting problems with excess fluid. In addition, patients with conditions that may be adversely affected by fluid accumulation, such as asthma, epilepsy, migraine, and cardiovascular or renal dysfunction, should be observed for exacerbation of their condition during estrogen and/or progestogen therapy.
Thrombotic/Thromboembolic Disorder
Major:Opill
The norgestrel in Opill has a major potential interaction with Thrombotic/Thromboembolic Disorder.
The use of progestogens, in general, is considered by manufacturers to be contraindicated in patients with active thrombophlebitis, cerebrovascular disease, or a current or past history of thromboembolic disorders. While the role of progestogens in the development of thromboembolic events associated with hormonal therapy is often unclear and thought to be secondary to that of estrogens, it may not be insignificant. Medroxyprogesterone, a common progestational agent, has been shown to produce a hypercoagulable state in high dosages. Whether or not this effect contributes to the development of thrombotic events is unknown. However, thrombophlebitis and pulmonary embolism have been reported with megestrol, an antineoplastic and progestational agent. In addition, an increased risk of nonfatal venous thrombosis has been associated with oral contraceptive combinations containing desogestrel or gestodene relative to those that contain other progestins (e.g., levonorgestrel, norethindrone), suggesting some degree of hemostatic effect by progestogens.
Thyroid Disease
Moderate:Opill
The norgestrel in Opill has a moderate potential interaction with Thyroid Disease.
When administering estrogen and/or progestogen therapy in patients with thyroid disorders, clinicians should be aware that these hormones may affect thyroid function tests. Patients on thyroid replacement therapy may require higher doses of thyroid hormone and appropriate monitoring. Changes have mostly been reported with the use of combination oral contraceptives. Specifically, thyroid-binding globulin (TBG) may be increased, resulting in elevated circulating total thyroid hormone, as measured by PBI (protein-bound iodine), T4 by column or radioimmunoassay, or T3 by radioimmunoassay. Free T3 resin uptake may be decreased. On the contrary, a decrease in TBG and, consequently, thyroxine concentration, has been reported by the manufacturers of the progestin-only (norethindrone) oral contraceptives.
Weight Loss
Minor:Opill
The norgestrel in Opill has a minor potential interaction with Weight Loss.
Progestogens can cause weight gain, which may be significant (as is the case with parenteral medroxyprogesterone) and undesirable in obese patients attempting to lose weight.
Drug Interaction Classification
| Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
| Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
| Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. | |
| No interaction information available. |
See also:
Learn more
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.