Skip to main content

Drug Interactions between IsonaRif and Zetran

This report displays the potential drug interactions for the following 2 drugs:

Edit list (add/remove drugs)

Interactions between your drugs

Major

rifAMPin isoniazid

Applies to: IsonaRif (isoniazid / rifampin) and IsonaRif (isoniazid / rifampin)

MONITOR CLOSELY: The risk of hepatotoxicity is greater when rifampin and isoniazid (INH) are given concomitantly, than when either drug is given alone. The proposed mechanism is rifampin's induction of isoniazid hydrolase, an enzyme involved in the conversion of INH to isonicotinic acid and hydrazine. Hydrazine is the proposed toxic metabolite of INH, which has been shown in animal studies to cause steatosis, hepatocyte vacuolation and glutathione depletion. Some studies have also shown that slow acetylators have a two-fold increased risk of developing antituberculosis drug-induced hepatotoxicity (ATDH) as compared with fast acetylators due to more available INH for direct hydrolysis to hydrazine. Theoretically, a similar reaction may occur with rifabutin and isoniazid. Additional risk factors for developing hepatotoxicity include patients with advanced age, malnutrition, existing hepatic impairment, daily alcohol consumption, female gender, HIV infection, extra-pulmonary tuberculosis and/or patients who are taking other potent CYP450-inducing agents.

MANAGEMENT: Caution and close monitoring should be considered if isoniazid (INH) is coadministered with rifampin or rifabutin. In cases where coadministration is required, careful monitoring of liver function, especially ALT and AST, should be done at baseline and then every 2 to 4 weeks during therapy, or in accordance with individual product labeling. Some manufacturers of INH recommend strongly considering its discontinuation if serum aminotransferase concentrations (AST or SGOT, ALT or SGPT) exceed 3 to 5 times the upper limit of normal. Product labeling for rifampin also recommends the immediate discontinuation of therapy if hepatic damage is suspected. INH product labeling suggests alternate drugs be used if hepatitis is attributed to INH in patients with tuberculosis. However, if INH must be used, it should only be resumed after the patient's symptoms and laboratory abnormalities have cleared. It should also be restarted in very small, gradually increasing doses and immediately withdrawn if there is any indication of recurrent liver involvement. Patients should be counseled to immediately report signs or symptoms consistent with liver damage and notified that prodromal symptoms usually consist of fatigue, weakness, malaise, anorexia, nausea, and/or vomiting.

References

  1. O'Brien RJ, Long MW, Cross FS, et al. "Hepatotoxicity from isoniazid and rifampin among children treated for tuberculosis." Pediatrics 72 (1983): 491-9
  2. Kumar A, Misra PK, Mehotra R, et al. "Hepatotoxicity of rifampin and isoniazid." Am Rev Respir Dis 143 (1991): 1350-2
  3. Abadie-Kemmerly S, Pankey GA, Dalvisio JR "Failure of ketoconazole treatment of blastomyces dermatidis due to interaction of isoniazid and rifampin." Ann Intern Med 109 (1988): 844-5
  4. Acocella G, Bonollo L, Garimoldi M, et al. "Kinetics of rifampicin and isoniazid administered alone and in combination to normal subjects and patients with liver disease." Gut 13 (1972): 47-53
  5. Yamamoto T, Suou T, Hirayama C "Elevated serum aminotransferase induced by isoniazid in relation to isoniazid acetylator phenotype." Hepatology 6 (1986): 295-8
  6. Steele MA, Burk RF, Des Prez RM "Toxic hepatitis with isoniazid and rifampin." Chest 99 (1991): 465-71
  7. "Product Information. INH (isoniazid)." Ciba Pharmaceuticals, Summit, NJ.
  8. Sarma G, Immanuel C, Kailasam S, Narayana AS, Venkatesan P "Rifampin-induced release of hydrazine from isoniazid." Am Rev Respir Dis 133 (1986): 1072-5
  9. "Product Information. Mycobutin (rifabutin)." Pharmacia and Upjohn PROD (2001):
  10. "Product Information. Rifadin (rifampin)." Hoechst Marion Roussel PROD (2001):
  11. Askgaard DS, Wilcke T, Dossing M "Hepatotoxicity caused by the combined action of isoniazid and rifampicin." Thorax 50 (1995): 213-4
  12. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  13. Canadian Pharmacists Association "e-CPS. http://www.pharmacists.ca/function/Subscriptions/ecps.cfm?link=eCPS_quikLink" (2006):
  14. Cerner Multum, Inc. "Australian Product Information." O 0
  15. "Product Information. Isoniazid (isoniazid)." Chartwell RX, LLC. (2023):
  16. "Product Information. Isoniazid (Arrotex) (isoniazid)." Arrotex Pharmaceuticals Pty Ltd (2023):
  17. "Product Information. Isoniazid (isoniazid)." RPH Pharmaceuticals AB (2023):
  18. Sarma GR, Immanual C, Kailasam S, Narayana AS, Venkatesan P "Rifampin-induced release of hydrazine from isoniazid. A possible cause of hepatitis during treatment of tuberculosis with regimens containing isoniazid and rifampin https://pubmed.ncbi.nlm.nih.gov/3717759/" (2024):
  19. Tostmann A, Boeree MJ, Aarnoutse RE, De Lange WCM, Van Der Ven AJAM, Dekhuijzen R "Antituberculosis drug-induced hepatotoxicity: concise up-to-date review https://onlinelibrary.wiley.com/doi/10.1111/j.1440-1746.2007.05207.x" (2024):
  20. "Product Information. Isotamine (isoniazid)." Bausch Health, Canada Inc. (2021):
  21. "Product Information. Rifampin (rifAMPin)." Akorn Inc (2022):
  22. "Product Information. Rifampicin (rifampicin)." Mylan Pharmaceuticals Inc (2022):
  23. "Product Information. Rifadin (rifampicin)." Sanofi (2023):
  24. "Product Information. Rifadin (rifaMPICin)." Sanofi-Aventis Australia Pty Ltd (2024):
  25. "Product Information. Rofact (rifampin)." Bausch Health, Canada Inc. (2019):
View all 25 references

Switch to consumer interaction data

Moderate

isoniazid diazePAM

Applies to: IsonaRif (isoniazid / rifampin) and Zetran (diazepam)

MONITOR: Coadministration with isoniazid (INH) may increase the plasma concentrations and therapeutic effects of benzodiazepines and related drugs that are primarily metabolized by CYP450 3A4 (e.g., diazepam, flurazepam, triazolam, midazolam, zopiclone, eszopiclone) and to a lesser extent, 2C9, 2C19, and/or 2E1. Isoniazid has been shown to be an inhibitor of these isoenzymes, although some data is limited to in vitro studies. Inhibition of the relevant CYP450 isoenzyme by INH may decrease the clearance and prolong the half-life of the benzodiazepine, leading to an elevated risk of benzodiazepine CNS side effects (e.g., sedation, respiratory depression). According to triazolam product labeling, coadministration of INH increased the peak plasma concentration (Cmax) of triazolam by 20%, decreased the clearance by 42%, and increased the half-life by 31%. Clinical data are not available for all benzodiazepines. In addition, the net effect on benzodiazepines when coadministered with other anti-tuberculosis agents that have additional CYP450 drug interactions (i.e. CYP450 3A4 induction by rifampin) have not been evaluated.

MANAGEMENT: Caution and clinical monitoring are advised when isoniazid is coadministered with benzodiazepines and related drugs that are substrates of CYP450 3A4, 2C9, 2C19, and/or 2E1. If coadministration is required, close clinical monitoring for adverse effects (e.g., sedation, respiratory depression) is advised and benzodiazepine dose adjustments may be required, particularly when isoniazid is initiated or withdrawn from concomitant therapy. Individual product labeling for the coadministered benzodiazepine should be consulted. Additional caution and clinical monitoring may be advised if isoniazid is being used in conjunction with, or immediately following treatment with other anti-tuberculosis agents that have additional CYP450 drug interactions (i.e. CYP450 3A4 induction by rifampin), as this may change the nature and/or severity of this drug interaction.

References

  1. Ochs HR, Greenblatt DJ, Knuchel M "Differential effect of isoniazid on triazolam oxidation and oxazepam conjugation." Br J Clin Pharmacol 16 (1983): 743-6
  2. Desta Z, Soukhova NV, Flockhart DA "Inhibition of cytochrome P450 (CYP450) isoforms by isoniazid: Potent inhibition of CYP2C19 and CYP3A." Antimicrob Agents Chemother 45 (2001): 382-92
  3. "Product Information. Isoniazid/Rifapentine 300 mg/300 mg (Macleods) (isoniazid-rifapentine)." Imported (India) 2 (2021):
  4. "Product Information. Isoniazid (isoniazid)." Chartwell RX, LLC. (2023):
  5. "Product Information. Isoniazid (Arrotex) (isoniazid)." Arrotex Pharmaceuticals Pty Ltd (2023):
  6. "Product Information. Isoniazid (isoniazid)." RPH Pharmaceuticals AB (2023):
  7. "Product Information. Triazolam (triazolam)." Greenstone LLC (2023):
View all 7 references

Switch to consumer interaction data

Minor

rifAMPin diazePAM

Applies to: IsonaRif (isoniazid / rifampin) and Zetran (diazepam)

Rifampin may decrease benzodiazepine serum levels. The mechanism is probably related to stimulation of the hepatic metabolism of benzodiazepines. Diazepam and triazolam have been specifically studied in this regard, although other benzodiazepines also may interact with rifampin. Additionally, rifabutin may have an interaction with benzodiazepines similar to that of rifampin.

References

  1. Ochs HR, Greenblatt DJ, Roberts GM, Dengler HJ "Diazepam interaction with antituberculosis drugs." Clin Pharmacol Ther 29 (1981): 671-8
  2. Villikka K, Kivisto KT, Backman JT, Olkkola KT, Neuvonen PJ "Triazolam is ineffective in patients taking rifampin." Clin Pharmacol Ther 61 (1997): 8-14
  3. Strayhorn VA, Baciewicz AM, Self TH "Update on rifampin drug interactions, III." Arch Intern Med 157 (1997): 2453-8

Switch to consumer interaction data

Drug and food interactions

Moderate

rifAMPin food

Applies to: IsonaRif (isoniazid / rifampin)

GENERALLY AVOID: Concurrent use of rifampin in patients who ingest alcohol daily may result in an increased incidence of hepatotoxicity. The increase in hepatotoxicity may be due to an additive risk as both alcohol and rifampin are individually associated with this adverse reaction. However, the exact mechanism has not been established.

ADJUST DOSING INTERVAL: Administration with food may reduce oral rifampin absorption, increasing the risk of therapeutic failure or resistance. In a randomized, four-period crossover phase I study of 14 healthy male and female volunteers, the pharmacokinetics of single dose rifampin 600 mg were evaluated under fasting conditions and with a high-fat meal. Researchers observed that administration of rifampin with a high-fat meal reduced rifampin peak plasma concentration (Cmax) by 36%, nearly doubled the time to reach peak plasma concentration (Tmax) but reduced overall exposure (AUC) by only 6%.

MANAGEMENT: The manufacturer of oral forms of rifampin recommends administration on an empty stomach, 30 minutes before or 2 hours after meals. Patients should be encouraged to avoid alcohol or strictly limit their intake. Patients who use alcohol and rifampin concurrently or have a history of alcohol use disorder may require additional monitoring of their liver function during treatment with rifampin.

References

  1. "Product Information. Rifampin (rifAMPin)." Akorn Inc (2022):
  2. "Product Information. Rifampicin (rifampicin)." Mylan Pharmaceuticals Inc (2022):
  3. "Product Information. Rifadin (rifampicin)." Sanofi (2023):
  4. "Product Information. Rifadin (rifaMPICin)." Sanofi-Aventis Australia Pty Ltd (2024):
  5. Peloquin CA, Namdar R, Singleton MD, Nix DE "Pharmacokinetics of rifampin under fasting conditions, with food, and with antacids https://pubmed.ncbi.nlm.nih.gov/9925057/" (2024):
  6. "Product Information. Rofact (rifampin)." Bausch Health, Canada Inc. (2019):
View all 6 references

Switch to consumer interaction data

Moderate

isoniazid food

Applies to: IsonaRif (isoniazid / rifampin)

GENERALLY AVOID: Concurrent use of isoniazid (INH) in patients who ingest alcohol daily may result in an increased incidence of both hepatotoxicity and peripheral neuropathy. The increase in hepatotoxicity may be due to an additive risk as both alcohol and INH are individually associated with this adverse reaction. INH-associated hepatotoxicity is believed to be due to an accumulation of toxic metabolites and may also be partly immune mediated, though the exact mechanisms are not universally agreed upon. INH is metabolized by N-acetyltransferase and CYP450 2E1. The rate of acetylation is genetically determined and generally classified as slow or rapid. Slow acetylators have been identified by some studies as having a higher risk of hepatotoxicity; therefore, this interaction may be more significant for patients who fall into this category. Other studies have postulated that alcohol-mediated CYP450 2E1 induction may play a role, as this isoenzyme is involved in INH metabolism and may be responsible for producing hepatotoxic metabolites. However, available literature is conflicting. The labeling for some INH products lists daily alcohol use or chronic alcoholism as a risk factor for hepatitis, but not all studies have found a significant association between alcohol use and INH-induced hepatotoxicity. Additionally, INH and alcohol are both associated with pyridoxine (B6) deficiency, which may increase the risk of peripheral neuropathy.

GENERALLY AVOID: Concomitant administration of isoniazid (INH) with foods containing tyramine and/or histamine may increase the risk of symptoms relating to tyramine- and/or histamine toxicity (e.g., headache, diaphoresis, flushing, palpitations, and hypotension). The proposed mechanism is INH-mediated inhibition of monoamine oxidase (MAO) and diamine oxidase (DAO), enzymes responsible for the metabolism of tyramine and histamine, respectively. Some authors have suggested that the reactions observed are mainly due to INH's effects on DAO instead of MAO or the amounts of histamine instead of tyramine present in the food. A Japanese case report recorded an example in 8 out of 25 patients on the tuberculosis ward who developed an accidental histamine poisoning after ingesting a fish paste (saury). Patients developed allergy-like symptoms, which started between 20 minutes and 2 hours after ingesting the food. A high-level of histamine (32 mg/100 g of fish) was confirmed in the saury paste and all 8 patients were both on INH and had reduced MAO concentrations. The 17 remaining patients were not on INH (n=5) or reported not eating the saury paste (n=12).

ADJUST DOSING INTERVAL: Administration with food significantly reduces oral isoniazid (INH) absorption, increasing the risk of therapeutic failure or resistance. The mechanism is unknown. Pharmacokinetic studies completed in both healthy volunteers (n=14) and tuberculosis patients (n=20 treatment-naive patients during days 1 to 3 of treatment) have resulted in almost doubling the time to reach INH's maximum concentration (tmax) and a reduction in isoniazid's maximum concentration (Cmax) of 42%-51% in patients who consumed high-fat or high-carbohydrate meals prior to INH treatment.

MANAGEMENT: The manufacturer of oral forms of isoniazid (INH) recommends administration on an empty stomach (i.e., 30 minutes before or 2 hours after meals). Patients should be encouraged to avoid alcohol or strictly limit their intake. Patients who use alcohol and INH concurrently or have a history of alcohol use disorder may require additional monitoring of their liver function during treatment with INH. Concomitant pyridoxine (B6) administration is also recommended to reduce the risk of peripheral neuropathy, with some authorities suggesting a dose of at least 10 mg/day. Patients should be advised to avoid foods containing tyramine (e.g., aged cheese, cured meats such as sausages and salami, fava beans, sauerkraut, soy sauce, beer, or red wine) or histamine (e.g., skipjack, tuna, mackerel, salmon) during treatment with isoniazid. Consultation of product labeling for combination products containing isoniazid and/or relevant guidelines may be helpful for more specific recommendations.

References

  1. Smith CK, Durack DT "Isoniazid and reaction to cheese." Ann Intern Med 88 (1978): 520-1
  2. Dimartini A "Isoniazid, tricyclics and the ''cheese reaction''." Int Clin Psychopharmacol 10 (1995): 197-8
  3. Uragoda CG, Kottegoda SR "Adverse reactions to isoniazid on ingestion of fish with a high histamine content." Tubercle 58 (1977): 83-9
  4. Self TH, Chrisman CR, Baciewicz AM, Bronze MS "Isoniazid drug and food interactions." Am J Med Sci 317 (1999): 304-11
  5. "Product Information. Isoniazid/Rifapentine 300 mg/300 mg (Macleods) (isoniazid-rifapentine)." Imported (India) 2 (2021):
  6. "Product Information. Isoniazid (isoniazid)." Chartwell RX, LLC. (2023):
  7. "Product Information. Isoniazid (Arrotex) (isoniazid)." Arrotex Pharmaceuticals Pty Ltd (2023):
  8. "Product Information. Isoniazid (isoniazid)." RPH Pharmaceuticals AB (2023):
  9. Saukkonen JJ, Cohn DL, Jasmer RM, et al. "An official ATS statement: hepatotoxicity of antituberculosis therapy." Am J Respir Crit Care Med 174 (2006): 935-52
  10. Bouazzi OE, Hammi S, Bourkadi JE, et al. "First line anti-tuberculosis induced hepatotoxicity: incidence and risk factors. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5326068/" (2024):
  11. Wang P, Pradhan K, Zhong XB, Ma X "Isoniazid metabolism and hepatoxicity." Acta Pharm Sin B 6 (2016): 384-92
  12. Saktiawati AM, Sturkenboom MG, Stienstra Y, et al. "Impact of food on the pharmacokinetics of first-line anti-TB drugs in treatment naive TB patients: a randomized cross-over trial." J Antimicrob Chemother 71 (2016): 703-10
  13. Hahn JA, Ngabirano C, Fatch R, et al. "Safety and tolerability of isoniazid preventive therapy for tuberculosis for persons with HIV with and without alcohol use." AIDS 37 (2023): 1535-43
  14. Huang YS, Chern HD, Su WJ, et al. "Cytochrome P450 2E1 genotype and the susceptibility to antituberculosis drug-induced hepatitis." Hepatology 37 (2003): 924-30
  15. Sousou JM, Griffith EM, Marsalisi C, Reddy P "Pyridoxine deficiency and neurologic dysfunction: an unlikely association. https://www.cureus.com/articles/188310-pyridoxine-deficiency-and-neurologic-dysfunction-an-unlikely-association?score_article=true#!/" (2024):
  16. Miki M, Ishikawa T, Okayama H "An outbreak of histamine poisoning after ingestion of the ground saury paste in eight patients taking isoniazid in tuberculous ward." Intern Med 44 (2005): 1133-6
  17. "Product Information. Isotamine (isoniazid)." Bausch Health, Canada Inc. (2021):
View all 17 references

Switch to consumer interaction data

Moderate

diazePAM food

Applies to: Zetran (diazepam)

GENERALLY AVOID: Acute alcohol ingestion may potentiate the CNS depression and other CNS effects of many benzodiazepines. Tolerance may develop with chronic ethanol use. The mechanism may be decreased clearance of the benzodiazepines because of CYP450 hepatic enzyme inhibition. Also, it has been suggested that the cognitive deficits induced by benzodiazepines may be increased in patients who chronically consume large amounts of alcohol.

MONITOR: Grapefruit juice may increase the plasma concentrations of orally administered drugs that are substrates of the CYP450 3A4 isoenzyme. However, the interaction seems to affect primarily those drugs that undergo significant presystemic metabolism by CYP450 3A4 (i.e., drugs with low oral bioavailability), presumably due to the fact that grapefruit juice inhibits intestinal rather than hepatic CYP450 3A4. Because pharmacokinetic interactions involving grapefruit juice are often subject to a high degree of interpatient variability, the extent to which a given patient may be affected is difficult to predict.

MANAGEMENT: Patients should be advised to avoid alcohol during benzodiazepine therapy. Patients who regularly consume grapefruit or grapefruit juice should be monitored for adverse effects and altered plasma concentrations of drugs that undergo significant presystemic metabolism by CYP450 3A4. Grapefruit and grapefruit juice should be avoided if an interaction is suspected. Orange juice is not expected to interact with these drugs.

References

  1. Edgar B, Bailey D, Bergstrand R, et al. "Acute effects of drinking grapefruit juice on the pharmacokinetics and dynamics on felodipine and its potential clinical relevance." Eur J Clin Pharmacol 42 (1992): 313-7
  2. Jonkman JH, Sollie FA, Sauter R, Steinijans VW "The influence of caffeine on the steady-state pharmacokinetics of theophylline." Clin Pharmacol Ther 49 (1991): 248-55
  3. "Product Information. Valium (diazepam)." Roche Laboratories PROD (2002):
  4. Bailey DG, Arnold JM, Munoz C, Spence JD "Grapefruit juice--felodipine interaction: mechanism, predictability, and effect of naringin." Clin Pharmacol Ther 53 (1993): 637-42
  5. Bailey DG, Arnold JMO, Spence JD "Grapefruit juice and drugs - how significant is the interaction." Clin Pharmacokinet 26 (1994): 91-8
  6. "Product Information. Doral (quazepam)." Wallace Laboratories PROD (2001):
  7. Sigusch H, Hippius M, Henschel L, Kaufmann K, Hoffmann A "Influence of grapefruit juice on the pharmacokinetics of a slow release nifedipine formulation." Pharmazie 49 (1994): 522-4
  8. Bailey DG, Arnold JM, Strong HA, Munoz C, Spence JD "Effect of grapefruit juice and naringin on nisoldipine pharmacokinetics." Clin Pharmacol Ther 54 (1993): 589-94
  9. Yamreudeewong W, Henann NE, Fazio A, Lower DL, Cassidy TG "Drug-food interactions in clinical practice." J Fam Pract 40 (1995): 376-84
  10. "Grapefruit juice interactions with drugs." Med Lett Drugs Ther 37 (1995): 73-4
  11. Hukkinen SK, Varhe A, Olkkola KT, Neuvonen PJ "Plasma concentrations of triazolam are increased by concomitant ingestion of grapefruit juice." Clin Pharmacol Ther 58 (1995): 127-31
  12. Min DI, Ku YM, Geraets DR, Lee HC "Effect of grapefruit juice on the pharmacokinetics and pharmacodynamics of quinidine in healthy volunteers." J Clin Pharmacol 36 (1996): 469-76
  13. Majeed A, Kareem A "Effect of grapefruit juice on cyclosporine pharmacokinetics." Pediatr Nephrol 10 (1996): 395
  14. Clifford CP, Adams DA, Murray S, Taylor GW, Wilkins MR, Boobis AR, Davies DS "Pharmacokinetic and cardiac effects of terfenadine after inhibition of its metabolism by grapefruit juice." Br J Clin Pharmacol 42 (1996): p662
  15. Josefsson M, Zackrisson AL, Ahlner J "Effect of grapefruit juice on the pharmacokinetics of amlodipine in healthy volunteers." Eur J Clin Pharmacol 51 (1996): 189-93
  16. Kantola T, Kivisto KT, Neuvonen PJ "Grapefruit juice greatly increases serum concentrations of lovastatin and lovastatin acid." Clin Pharmacol Ther 63 (1998): 397-402
  17. Ozdemir M, Aktan Y, Boydag BS, Cingi MI, Musmul A "Interaction between grapefruit juice and diazepam in humans." Eur J Drug Metab Pharmacokinet 23 (1998): 55-9
  18. Bailey DG, Malcolm J, Arnold O, Spence JD "Grapefruit juice-drug interactions." Br J Clin Pharmacol 46 (1998): 101-10
  19. Bailey DG, Kreeft JH, Munoz C, Freeman DJ, Bend JR "Grapefruit juice felodipine interaction: Effect of naringin and 6',7'-dihydroxybergamottin in humans." Clin Pharmacol Ther 64 (1998): 248-56
  20. Garg SK, Kumar N, Bhargava VK, Prabhakar SK "Effect of grapefruit juice on carbamazepine bioavailability in patients with epilepsy." Clin Pharmacol Ther 64 (1998): 286-8
  21. Lilja JJ, Kivisto KT, Neuvonen PJ "Grapefruit juice-simvastatin interaction: Effect on serum concentrations of simvastatin, simvastatin acid, and HMG-CoA reductase inhibitors." Clin Pharmacol Ther 64 (1998): 477-83
  22. Fuhr U, Maier-Bruggemann A, Blume H, et al. "Grapefruit juice increases oral nimodipine bioavailability." Int J Clin Pharmacol Ther 36 (1998): 126-32
  23. Lilja JJ, Kivisto KT, Neuvonen PJ "Grapefruit juice increases serum concentrations of atorvastatin and has no effect on pravastatin." Clin Pharmacol Ther 66 (1999): 118-27
  24. Eagling VA, Profit L, Back DJ "Inhibition of the CYP3A4-mediated metabolism and P-glycoprotein-mediated transport of the HIV-I protease inhibitor saquinavir by grapefruit juice components." Br J Clin Pharmacol 48 (1999): 543-52
  25. Damkier P, Hansen LL, Brosen K "Effect of diclofenac, disulfiram, itraconazole, grapefruit juice and erythromycin on the pharmacokinetics of quinidine." Br J Clin Pharmacol 48 (1999): 829-38
  26. Lee AJ, Chan WK, Harralson AF, Buffum J, Bui BCC "The effects of grapefruit juice on sertraline metabolism: An in vitro and in vivo study." Clin Ther 21 (1999): 1890-9
  27. Dresser GK, Spence JD, Bailey DG "Pharmacokinetic-pharmacodynamic consequences and clinical relevance of cytochrome P450 3A4 inhibition." Clin Pharmacokinet 38 (2000): 41-57
  28. Gunston GD, Mehta U "Potentially serious drug interactions with grapefruit juice." S Afr Med J 90 (2000): 41
  29. Takanaga H, Ohnishi A, Maatsuo H, et al. "Pharmacokinetic analysis of felodipine-grapefruit juice interaction based on an irreversible enzyme inhibition model." Br J Clin Pharmacol 49 (2000): 49-58
  30. Libersa CC, Brique SA, Motte KB, et al. "Dramatic inhibition of amiodarone metabolism induced by grapefruit juice." Br J Clin Pharmacol 49 (2000): 373-8
  31. Bailey DG, Dresser GR, Kreeft JH, Munoz C, Freeman DJ, Bend JR "Grapefruit-felodipine interaction: Effect of unprocessed fruit and probable active ingredients." Clin Pharmacol Ther 68 (2000): 468-77
  32. Zaidenstein R, Soback S, Gips M, Avni B, Dishi V, Weissgarten Y, Golik A, Scapa E "Effect of grapefruit juice on the pharmacokinetics of losartan and its active metabolite E3174 in healthy volunteers." Ther Drug Monit 23 (2001): 369-73
  33. Sato J, Nakata H, Owada E, Kikuta T, Umetsu M, Ito K "Influence of usual intake of dietary caffeine on single-dose kinetics of theophylline in healthy human subjects." Eur J Clin Pharmacol 44 (1993): 295-8
  34. Flanagan D "Understanding the grapefruit-drug interaction." Gen Dent 53 (2005): 282-5; quiz 286
View all 34 references

Switch to consumer interaction data

Minor

diazePAM food

Applies to: Zetran (diazepam)

One study has reported a 22% reduction in diazepam plasma levels when coadministered with caffeine. The exact mechanism of this interaction has not been specified. Physicians and patients should be aware that changes to caffeine consumption habits may impact the efficacy of diazepam therapy.

References

  1. Ghoneim MM, Hinrichs JV, Chiang CK, Loke WH "Pharmacokinetic and pharmacodynamic interactions between caffeine and diazepam." J Clin Psychopharmacol 6 (1986): 75-80

Switch to consumer interaction data

Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.

See also

Report options

Loading...
QR code containing a link to this page

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor 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.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer