Interactions between Afeditab CR and Ethotoin

Ethotoin has a moderate potential interaction with Abnormal Glucose Tolerance.

Phenytoin, particularly in high dosages, may cause hyperglycemia by inhibiting insulin release. The drug may also raise serum glucose levels in diabetic patients. Therapy with phenytoin should be administered cautiously in patients with diabetes mellitus, glucose intolerance, or a predisposition to hyperglycemia. Patients with diabetes mellitus should be monitored more closely during phenytoin therapy, and their antidiabetic regimen adjusted accordingly. The same precautions should also be observed with other hydantoin anticonvulsants (i.e. ethotoin and mephenytoin) because of their structural and pharmacological similarities to phenytoin.

Ethotoin has a moderate potential interaction with Anemia, Folate Deficiency.

Hydantoin anticonvulsants may interfere with folate metabolism and precipitate macrocytosis and megaloblastic anemia, which usually respond to folic acid therapy. These reactions have been fairly uncommon but may be of concern in patients with megaloblastic anemia or folate deficiency receiving hydantoin therapy.

The NIFEdipine in Afeditab CR has a major potential interaction with Aortic Stenosis.

The use of some calcium channel blockers (CCBs) is contraindicated in patients with advanced aortic stenosis. CCBs whose pharmacologic effect is partially dependent on their ability to reduce afterload (e.g., diltiazem, nicardipine, nifedipine, verapamil) may be of less benefit in these patients due to a fixed impedance to flow across the aortic valve and may, in fact, worsen rather than improve myocardial oxygen balance. Rarely, heart failure has developed following the initiation of these CCBs, particularly in patients receiving concomitant beta-blocker therapy.

Ethotoin has a major potential interaction with Bone Marrow Depression/Low Blood Counts.

Hematologic toxicities have been associated with the use of hydantoin anticonvulsants, particularly mephenytoin. Thrombocytopenia, leukopenia, neutropenia, agranulocytosis, pancytopenia and, rarely, hemolytic anemia, aplastic anemia and pure red cell aplasia have been reported. Therapy with hydantoin anticonvulsants should be administered cautiously in patients with preexisting blood dyscrasias and/or bone marrow depression. Complete blood counts, including platelets, should be performed prior to initiating therapy and regularly for several months thereafter. For mephenytoin, the manufacturer recommends performing counts after 2 weeks on a low dosage, after another 2 weeks when full dosage is reached, then monthly for a year, and every 3 months thereafter. Marked depression of blood counts may be indication for withdrawal of hydantoin therapy.

The NIFEdipine in Afeditab CR has a major potential interaction with Cardiogenic Shock.

In general, calcium channel blockers (CCBs) should not be used in patients with hypotension (systolic pressure < 90 mm Hg) or cardiogenic shock. Due to potential negative inotropic and peripheral vasodilating effects, the use of CCBs may further depress cardiac output and blood pressure, which can be detrimental in these patients. The use of verapamil and diltiazem is specifically contraindicated under these circumstances.

Ethotoin 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.

Ethotoin has a moderate potential interaction with Diabetes Mellitus.

Phenytoin, particularly in high dosages, may cause hyperglycemia by inhibiting insulin release. The drug may also raise serum glucose levels in diabetic patients. Therapy with phenytoin should be administered cautiously in patients with diabetes mellitus, glucose intolerance, or a predisposition to hyperglycemia. Patients with diabetes mellitus should be monitored more closely during phenytoin therapy, and their antidiabetic regimen adjusted accordingly. The same precautions should also be observed with other hydantoin anticonvulsants (i.e. ethotoin and mephenytoin) because of their structural and pharmacological similarities to phenytoin.

Ethotoin has a moderate potential interaction with Folic Acid/Cyanocobalamin Deficiency.

Hydantoin anticonvulsants may interfere with folate metabolism and precipitate macrocytosis and megaloblastic anemia, which usually respond to folic acid therapy. These reactions have been fairly uncommon but may be of concern in patients with megaloblastic anemia or folate deficiency receiving hydantoin therapy.

The NIFEdipine in Afeditab CR has a moderate potential interaction with Gastrointestinal Obstruction.

The extended-release formulation of nifedipine (Procardia XL) contains a non-deformable material. There have been rare reports of obstructive symptoms in patients with known strictures following the ingestion of similar sustained-release products. Therapy with the extended-release formulation of nifedipine should be administered cautiously in patients with preexisting severe gastrointestinal narrowing or obstruction, whether pathologic or iatrogenic.

The NIFEdipine in Afeditab CR has a major potential interaction with Heart Attack.

Nifedipine capsules should not be administered within the first two weeks after myocardial infarction, and they should also be avoided in the setting of acute coronary syndrome (when myocardial infarction may be imminent). Clinical trials studying the use of immediate-release nifedipine in patients who had just sustained myocardial infarctions have not demonstrated any benefit and in some cases patients had worse outcomes compared to those who received placebo.

The NIFEdipine in Afeditab CR has a moderate potential interaction with Heart Attack.

Calcium channel blockers (CCBs) may have varying degrees of negative inotropic effect. Congestive heart failure (CHF), worsening of CHF, and pulmonary edema have occurred in some patients treated with a CCB, primarily verapamil. Some CCBs have also caused mild to moderate peripheral edema due to localized vasodilation of dependent arterioles and small blood vessels, which can be confused with the effects of increasing left ventricular dysfunction. Although some CCBs have been used in the treatment of CHF, therapy with CCBs should be administered cautiously in patients with severe left ventricular dysfunction (e.g., ejection fraction < 30%) or moderate to severe symptoms of cardiac failure and in patients with any degree of ventricular dysfunction if they are receiving a beta-adrenergic blocker. Likewise, caution is advised in patients with acute myocardial infarction and pulmonary congestion documented by X-ray on admission, since associated heart failure may be acutely worsened by administration of a CCB.

The NIFEdipine in Afeditab CR has a moderate potential interaction with Heart Failure.

Calcium channel blockers (CCBs) may have varying degrees of negative inotropic effect. Congestive heart failure (CHF), worsening of CHF, and pulmonary edema have occurred in some patients treated with a CCB, primarily verapamil. Some CCBs have also caused mild to moderate peripheral edema due to localized vasodilation of dependent arterioles and small blood vessels, which can be confused with the effects of increasing left ventricular dysfunction. Although some CCBs have been used in the treatment of CHF, therapy with CCBs should be administered cautiously in patients with severe left ventricular dysfunction (e.g., ejection fraction < 30%) or moderate to severe symptoms of cardiac failure and in patients with any degree of ventricular dysfunction if they are receiving a beta-adrenergic blocker. Likewise, caution is advised in patients with acute myocardial infarction and pulmonary congestion documented by X-ray on admission, since associated heart failure may be acutely worsened by administration of a CCB.

The NIFEdipine in Afeditab CR has a major potential interaction with High Blood Pressure.

For the long-term treatment of hypertension, only the extended-release formulations of nifedipine should be used. The US National Heart, Lung, and Blood Institute and the FDA Cardiovascular and Renal Drug Advisory Committee have issued warnings against the use of immediate-release nifedipine for this purpose based on review of three epidemiologic studies of patients with hypertension and unstable angina who were treated with calcium channel blockers (CCBs) and at least two meta-analyses of randomized, controlled trials that included patients receiving CCBs. Two of the case-control studies found an increased risk of myocardial infarction (MI) in patients taking immediate-release nifedipine, although the third did not.

The use of immediate-release nifedipine (orally or sublingually) is also contraindicated for acute reduction of blood pressure. Profound hypotension, acute myocardial infarction, and deaths have been reported when nifedipine was used in this manner.

The NIFEdipine in Afeditab CR has a major potential interaction with Hypotension.

In general, calcium channel blockers (CCBs) should not be used in patients with hypotension (systolic pressure < 90 mm Hg) or cardiogenic shock. Due to potential negative inotropic and peripheral vasodilating effects, the use of CCBs may further depress cardiac output and blood pressure, which can be detrimental in these patients. The use of verapamil and diltiazem is specifically contraindicated under these circumstances.

The NIFEdipine in Afeditab CR has a major potential interaction with Ischemic Heart Disease.

Increased frequency, duration, and/or severity of angina, as well as acute myocardial infarction, have rarely developed during initiation or dosage increase of calcium channel blockers (CCBs), particularly in patients with severe obstructive coronary artery disease and those treated with immediate-release formulations. The mechanism of this effect is not established. Therapy with CCBs should be administered cautiously in patients with significant coronary artery disease.

The NIFEdipine in Afeditab CR has a major potential interaction with Liver Disease.

Calcium channel blockers (CCBs) are extensively metabolized by the liver. The half-lives of CCBs may be prolonged substantially in patients with severe hepatic impairment, with the potential for significant drug accumulation. In addition, the use of some CCBs has been associated with elevations in serum transaminases, both with and without concomitant elevations in alkaline phosphatase and bilirubin. While these effects may be transient and reversible, some patients have developed cholestasis or hepatocellular injury. Therapy with CCBs should be administered cautiously and often at reduced dosages in patients with significantly impaired hepatic function. Periodic monitoring of liver function is advised.

Ethotoin has a major potential interaction with Liver Disease.

Hydantoin anticonvulsants are primarily metabolized by the liver. Both metabolic activity and plasma protein binding may be significantly altered in patients with liver disease, resulting in elevated drug levels (total and unbound fraction) and increased risk of toxicity. Therapy with hydantoin anticonvulsants should be administered cautiously in patients with impaired hepatic function. Reduced dosages and slower titration may be necessary. In addition, periodic monitoring of liver function is recommended, since the use of anticonvulsants, including hydantoins, has been associated with hepatotoxicity related to drug hypersensitivity. Hepatic failure and death have occurred. Hydantoin therapy should be discontinued and not readministered if evidence of liver damage is observed and felt to be drug-related.

Ethotoin has a major potential interaction with Porphyria.

The use of phenytoin has rarely been associated with exacerbation of porphyria. Therapy with phenytoin should be administered cautiously in patients with porphyria. The same precaution should also be observed with other hydantoin anticonvulsants (i.e. ethotoin and mephenytoin) because of their structural and pharmacological similarities to phenytoin.

Ethotoin 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.

The NIFEdipine in Afeditab CR has a moderate potential interaction with Renal Dysfunction.

Although the clearance of nifedipine is not dependent on renal function, use of the drug in patients with uremia has been associated with enhanced pharmacologic effects, possibly due to increased sensitivity to the drug or reduced protein binding. Rarely, reversible elevations in BUN and serum creatinine have been reported in patients with preexisting chronic renal insufficiency given nifedipine, although a causal relationship has not been established. Nephritis and renal failure have also been observed. Therapy with nifedipine should be administered cautiously in patients with significantly impaired renal function.

Ethotoin has a moderate potential interaction with Vitamin D Deficiency.

Phenytoin may interfere with vitamin D metabolism. Hypocalcemia and osteomalacia have been reported. Therapy with phenytoin should be administered cautiously in patients with preexisting vitamin D deficiency. The same precaution should also be observed with other hydantoin anticonvulsants (i.e. ethotoin and mephenytoin) because of their structural and pharmacological similarities to phenytoin.