Drug Interaction Report
1 drug interaction and 22 additional warnings found for the following 2 drugs:
- lonafarnib
- mephobarbital
Drug interactions
Minor drug interactions
Minor:mephobarbital lonafarnib
Applies to: mephobarbital, lonafarnib
Information for this minor interaction is available on the professional version.
Food/lifestyle interactions
Major food/lifestyle interactions
Major:Alcohol (Ethanol) mephobarbital
Applies to: mephobarbital
Ask your doctor before using mephobarbital together with ethanol (alcohol), this can add to dizziness, drowsiness and other side effects of mephobarbital. Be careful if you drive or do activities that require you to be awake and alert. Talk with your doctor before using any medications together, or drinking alcohol with mephobarbital. 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.
Major:Food/Lifestyle lonafarnib
Applies to: lonafarnib
Consuming grapefruit, grapefruit juice, grapefruit hybrids, starfruit, and Seville oranges (also known as bitter or sour oranges) during treatment with lonafarnib is not recommended. Doing so may significantly increase the blood levels and effects of lonafarnib. This may increase the risk of an irregular heart rhythm that may be serious and potentially life-threatening. You may be more susceptible if you have a heart condition called congenital long QT syndrome, other cardiac diseases, conduction abnormalities, or electrolyte disturbances (for example, magnesium or potassium loss due to severe or prolonged diarrhea or vomiting). The risk and/or severity of other side effects may also increase, including nausea, vomiting, diarrhea, loss of appetite, electrolyte (e.G., calcium, magnesium, potassium, phosphate, sodium) abnormalities, liver problems, low red and white blood cell counts, infection, and high blood pressure. Additionally, you should take lonafarnib with the morning and evening meals and an adequate amount of water. You should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or heart palpitations during treatment. Talk to your doctor if you have any questions or concerns. 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.
Disease interactions
20 potential interactionsApplies to: 17 conditions, including Depression, Vitamin D Deficiency, Psychosis, Adrenal Insufficiency, and Liver Disease.
Acute Alcohol Intoxication
Major:mephobarbital
Mephobarbital has a major potential interaction with Acute Alcohol Intoxication.
The use of barbiturates is contraindicated in patients with acute alcohol intoxication exhibiting depressed vital signs. The central nervous system depressant effects of barbiturates may be additive with those of alcohol. Severe respiratory depression and death may occur. Therapy with barbiturates should be administered cautiously in patients who might be prone to acute alcohol intake.
Adrenal Insufficiency
Moderate:mephobarbital
Mephobarbital has a moderate potential interaction with Adrenal Insufficiency.
Barbiturates, especially phenobarbital, secobarbital and butabarbital, may diminish the systemic effects of exogenous and endogenous corticosteroids via induction of hepatic microsomal enzymes, thereby accelerating the metabolism of corticosteroids. In addition, barbiturates may interfere with pituitary corticotropin production. Therapy with barbiturates should be administered cautiously in patients with adrenal insufficiency. Patients with borderline hypoadrenalism should be monitored closely, and patients receiving steroid supplementation may require an adjustment in dosage when barbiturates are added to or withdrawn from their medication regimen.
Alcoholism
Major:mephobarbital
Mephobarbital has a major potential interaction with Alcoholism.
Barbiturates have the potential to cause dependence and abuse. Tolerance as well as physical and psychological dependence can develop, particularly after prolonged use of excessive dosages. Abrupt cessation and/or a reduction in dosage may precipitate withdrawal symptoms. In patients who have developed tolerance to a barbiturate, overdosage can still produce respiratory depression and death, and cross-tolerance usually will occur with other agents in the class. Addiction-prone individuals, such as those with a history of alcohol or substance abuse, should be under careful surveillance or medical supervision when treated with barbiturates. It may be prudent to refrain from dispensing large quantities of medication to these patients. After prolonged use or if dependency is suspected, withdrawal of barbiturates should be undertaken gradually using a dosage-tapering schedule.
Asphyxia
Major:mephobarbital
Mephobarbital has a major potential interaction with Asphyxia.
Barbiturates may produce severe respiratory depression, apnea, laryngospasm, bronchospasm and cough, particularly during rapid intravenous administration. In usual hypnotic dosages, the degree of respiratory depression produced is similar to that which occurs during physiologic sleep, while at higher dosages, the rate, depth and volume of respiration may be markedly decreased. However, some patients may be susceptible at commonly used dosages, including the elderly, debilitated or severely ill patients, those receiving other CNS depressants, and those with limited ventilatory reserve, chronic pulmonary insufficiency or other respiratory disorders. Therapy with barbiturates should be administered cautiously in these patients. Appropriate monitoring and individualization of dosage are particularly important, and equipment for resuscitation should be immediately available if the parenteral route is used. Barbiturates, especially injectable formulations, should generally be avoided in patients with sleep apnea, hypoxia, or severe pulmonary diseases in which dyspnea or obstruction is evident.
Bone Marrow Depression/Low Blood Counts
Moderate:mephobarbital
Mephobarbital has a moderate potential interaction with Bone Marrow Depression/Low Blood Counts.
Hematologic toxicity, including agranulocytosis, thrombocytopenic purpura and megaloblastic anemia, has been reported rarely during use of barbiturates. Therapy with barbiturates should be administered cautiously in patients with preexisting blood dyscrasias or bone marrow suppression. Blood counts are recommended prior to and periodically during long-term therapy, and patients should be instructed to immediately report any signs or symptoms suggestive of blood dyscrasia such as fever, sore throat, local infection, easy bruising, petechiae, bleeding, pallor, dizziness, or jaundice. Barbiturate therapy should be discontinued if blood dyscrasias occur.
Depression
Moderate:mephobarbital
Mephobarbital has a moderate potential interaction with Depression.
Barbiturates depress the central nervous system and may cause or exacerbate mental depression. Therapy with barbiturates should be administered cautiously in patients with a history of depression or suicidal tendencies. It may be prudent to refrain from dispensing large quantities of medication to these patients.
Moderate:mephobarbital
Mephobarbital 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.
Dermatitis, Drug-Induced
Major:mephobarbital
Mephobarbital has a major potential interaction with Dermatitis, Drug-Induced.
Skin eruptions may precede rare but potentially fatal barbiturate-induced reactions such as systemic lupus erythematosus and exfoliative dermatitis, the latter of which may be accompanied by hepatitis and jaundice. Therapy with barbiturates should be administered cautiously in patients with preexisting drug-induced dermatitis, since it may delay the recognition of a potential reaction to barbiturates. Barbiturate therapy should be withdrawn promptly at the first sign of a dermatologic adverse effect. However, cutaneous reactions may proceed to an irreversible stage even after cessation of medication due to the slow rate of metabolism and excretion of barbiturates. Patients should be advised to promptly report signs that may indicate impending development of barbiturate-related cutaneous lesions, including high fever, severe headache, stomatitis, conjunctivitis, rhinitis, urethritis, and balanitis. Rashes may be more likely to occur with phenobarbital and mephobarbital.
Drug Dependence
Major:mephobarbital
Mephobarbital has a major potential interaction with Drug Dependence.
Barbiturates have the potential to cause dependence and abuse. Tolerance as well as physical and psychological dependence can develop, particularly after prolonged use of excessive dosages. Abrupt cessation and/or a reduction in dosage may precipitate withdrawal symptoms. In patients who have developed tolerance to a barbiturate, overdosage can still produce respiratory depression and death, and cross-tolerance usually will occur with other agents in the class. Addiction-prone individuals, such as those with a history of alcohol or substance abuse, should be under careful surveillance or medical supervision when treated with barbiturates. It may be prudent to refrain from dispensing large quantities of medication to these patients. After prolonged use or if dependency is suspected, withdrawal of barbiturates should be undertaken gradually using a dosage-tapering schedule.
Hyperkinetic Syndrome of Childhood
Moderate:mephobarbital
Mephobarbital has a moderate potential interaction with Hyperkinetic Syndrome of Childhood.
Paradoxical reactions characterized by excitability and restlessness may occur in pediatric patients with hyperactive aggressive disorders. Such patients should be monitored for signs of paradoxical stimulation during therapy with barbiturates.
Liver Disease
Major:mephobarbital
Mephobarbital has a major potential interaction with Liver Disease.
Barbiturates are extensively metabolized by the liver. The plasma clearance of barbiturates may be decreased and the half-lives prolonged in patients with impaired hepatic function. Therapy with barbiturates should be administered cautiously and initiated at reduced dosages in patients with liver disease. Barbiturates are not recommended for use in patients with cirrhosis, hepatic failure, hepatic coma, or other severe hepatic impairment.
Moderate:lonafarnib
Lonafarnib has a moderate potential interaction with Liver Disease.
Hepatic transaminase elevations (i.e., aspartate aminotransferase AST] and alanine aminotransferase ([ALT]) have been reported during lonafarnib therapy. Often these elevations improve with continued therapy, but it is not possible to exclude this drug as a cause of the abnormalities. Liver enzymes should be monitored periodically during therapy.
Panhypopituitarism
Moderate:mephobarbital
Mephobarbital has a moderate potential interaction with Panhypopituitarism.
Barbiturates, especially phenobarbital, secobarbital and butabarbital, may diminish the systemic effects of exogenous and endogenous corticosteroids via induction of hepatic microsomal enzymes, thereby accelerating the metabolism of corticosteroids. In addition, barbiturates may interfere with pituitary corticotropin production. Therapy with barbiturates should be administered cautiously in patients with adrenal insufficiency. Patients with borderline hypoadrenalism should be monitored closely, and patients receiving steroid supplementation may require an adjustment in dosage when barbiturates are added to or withdrawn from their medication regimen.
Porphyria
Major:mephobarbital
Mephobarbital has a major potential interaction with Porphyria.
The use of barbiturates is contraindicated in patients with a history of porphyria. Barbiturates may exacerbate acute intermittent porphyria or porphyria variegata by inducing the enzymes responsible for porphyrin synthesis.
Psychosis
Moderate:mephobarbital
Mephobarbital 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.
Pulmonary Impairment
Major:mephobarbital
Mephobarbital has a major potential interaction with Pulmonary Impairment.
Barbiturates may produce severe respiratory depression, apnea, laryngospasm, bronchospasm and cough, particularly during rapid intravenous administration. In usual hypnotic dosages, the degree of respiratory depression produced is similar to that which occurs during physiologic sleep, while at higher dosages, the rate, depth and volume of respiration may be markedly decreased. However, some patients may be susceptible at commonly used dosages, including the elderly, debilitated or severely ill patients, those receiving other CNS depressants, and those with limited ventilatory reserve, chronic pulmonary insufficiency or other respiratory disorders. Therapy with barbiturates should be administered cautiously in these patients. Appropriate monitoring and individualization of dosage are particularly important, and equipment for resuscitation should be immediately available if the parenteral route is used. Barbiturates, especially injectable formulations, should generally be avoided in patients with sleep apnea, hypoxia, or severe pulmonary diseases in which dyspnea or obstruction is evident.
Renal Dysfunction
Major:mephobarbital
Mephobarbital has a major potential interaction with Renal Dysfunction.
The long-acting barbiturate, phenobarbital, is partially eliminated by the kidney. The plasma clearance of phenobarbital may be decreased and the half-life prolonged in patients with impaired renal function. Therapy with phenobarbital should be administered cautiously and initiated at reduced dosages in patients with renal impairment. Since approximately 75% of a mephobarbital dose is metabolized to phenobarbital, the same precaution should be observed with mephobarbital. The remaining barbiturates, which are short- and intermediate-acting, are all negligibly excreted in the urine and may be appropriate alternatives in these patients.
Moderate:lonafarnib
Lonafarnib has a moderate potential interaction with Renal Dysfunction.
Lonafarnib has not been studied in patients with renal impairment, however, this drug caused nephrotoxicity in rats at plasma drug exposures approximately equal to that achieved with the human dose. Renal function should be monitored at regular intervals during therapy.
Respiratory Arrest
Major:mephobarbital
Mephobarbital has a major potential interaction with Respiratory Arrest.
Barbiturates may produce severe respiratory depression, apnea, laryngospasm, bronchospasm and cough, particularly during rapid intravenous administration. In usual hypnotic dosages, the degree of respiratory depression produced is similar to that which occurs during physiologic sleep, while at higher dosages, the rate, depth and volume of respiration may be markedly decreased. However, some patients may be susceptible at commonly used dosages, including the elderly, debilitated or severely ill patients, those receiving other CNS depressants, and those with limited ventilatory reserve, chronic pulmonary insufficiency or other respiratory disorders. Therapy with barbiturates should be administered cautiously in these patients. Appropriate monitoring and individualization of dosage are particularly important, and equipment for resuscitation should be immediately available if the parenteral route is used. Barbiturates, especially injectable formulations, should generally be avoided in patients with sleep apnea, hypoxia, or severe pulmonary diseases in which dyspnea or obstruction is evident.
Vitamin D Deficiency
Moderate:mephobarbital
Mephobarbital has a moderate potential interaction with Vitamin D Deficiency.
Rickets and osteomalacia have rarely been reported following prolonged use of barbiturates, possibly due to increased metabolism of vitamin D as a result of enzyme induction by barbiturates. Long-term therapy with barbiturates should be administered cautiously in patients with vitamin D deficiency.
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. |
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