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Drug Interactions between diazepam and mefloquine

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

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Interactions between your drugs

Moderate

diazePAM mefloquine

Applies to: diazepam and mefloquine

GENERALLY AVOID: Mefloquine may increase the risk of seizures and decrease the effectiveness of anticonvulsant drugs in patients with epilepsy. The use of mefloquine alone and in combination with other related antimalarial agents (e.g., quinine, quinidine, chloroquine) has been associated with convulsions in some patients. Coadministration of mefloquine with certain anticonvulsant medications may also result in reduced seizure control by lowering the plasma levels of the anticonvulsant. In one case report, a patient with a seizure disorder previously well controlled on valproic acid and carbamazepine experienced several seizure episodes after taking mefloquine (250 mg weekly) for malaria prophylaxis. A subsequent kinetics study performed on the patient revealed a significant reduction in sodium valproate half-life (5.65 hours vs. reported normal of 8 to 20 hours) and no change in carbamazepine half-life. The author suggested that mefloquine be administered to epileptic patients with caution, particularly if being treated with sodium valproate. Additional clinical data with other antiepileptics are unavailable.

MANAGEMENT: According to product labeling, mefloquine may precipitate convulsions in patients with a history of seizure disorder and should not be used for malaria prophylaxis in such patients. If mefloquine administration is required for curative treatment of malaria, anticonvulsant blood levels should be closely monitored and the anticonvulsant dosage adjusted accordingly as needed. Patients should be advised to notify their physician if they experience a loss of seizure control.

References

  1. Singh K, Shanks GD, Wilde H (1991) "Seizures after mefloquine." Ann Intern Med, 114, p. 994
  2. Weinke T, Trautmann M, Held T, et al. (1991) "Neuropsychiatric side effects after the use of mefloquine." Am J Trop Med Hyg, 45, p. 86-91
  3. Bem JL, Kerr L, Stuerchler D (1992) "Mefloquine prophylaxis: an overview of spontaneous reports of severe psychiatric reactions and convulsions." J Trop Med Hyg, 95, p. 167-79
  4. Jallon P (1988) "Use of mefloquine in epileptic patients." J Neurol Neurosurg Psychiatry, 51, p. 732
  5. (2021) "Product Information. Mefloquine Hydrochloride (mefloquine)." Hikma USA (formerly West-Ward Pharmaceutical Corporation)
  6. Ries S, Pohlmanneden B (1993) "Seizures during malaria prophylaxis with mefloquine." Dtsch Med Wochenschr, 118, p. 1911-2
  7. Ruff TA, Sherwen SJ, Donnan GA (1994) "Seizure associated with mefloquine for malaria prophylaxis." Med J Aust, 161, p. 453
  8. Pous E, Gascon J, Obach J, Corachan M (1995) "Mefloquine-induced grand mal seizure during malaria chemoprophylaxis in a non-epileptic subject." Trans R Soc Trop Med Hyg, 89, p. 434
  9. Potasman I, Juven Y, Weller B, Schwartz E (2002) "Does mefloquine prophylaxis affect electroencephalographic patterns?" Am J Med, 112, p. 147-9
  10. Jimenez-Huete A, Gil-Nagel A, Franch O (2002) "Multifocal myoclonus associated with mefloquine chemoprophylaxis." Clin Neuropharmacol, 25, p. 243
  11. Ridtitid W, Wongnawa M, Mahatthanatrakul W, Chaipol P, Sunbhanich M (2000) "Effect of rifampin on plasma concentrations of mefloquine in healthy volunteers." J Pharm Pharmacol, 52, p. 1265-9
  12. (2022) "Product Information. Lariam (mefloquine)." Pharmaco Australia Ltd
  13. (2017) "Product Information. Mefloquine (mefloquine)." AA Pharma Inc
  14. (2022) "Product Information. Lariam (mefloquine)." Neon Healthcare Ltd
View all 14 references

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Drug and food interactions

Moderate

diazePAM food

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

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Moderate

mefloquine food

Applies to: mefloquine

ADJUST DOSING INTERVAL: Food enhances the oral absorption and bioavailability of mefloquine. The proposed mechanism is increased drug solubility in the presence of food. In 20 healthy volunteers, administration of a single 750 mg oral dose of mefloquine 30 minutes following a high-fat meal increased the mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of mefloquine by 73% and 40%, respectively, compared to administration in the fasting state. The Cmax and AUC of the carboxylic acid metabolite were also increased by 35% and 33%, respectively, compared to fasting. In addition, the time to reach peak plasma concentration (Tmax) of mefloquine was significantly shorter after food intake (17 hours) than in the fasting state (36 hours). There was no difference in the elimination half-life of mefloquine and metabolite, or the Tmax for the metabolite.

MANAGEMENT: To ensure maximal oral absorption, mefloquine should be administered immediately after a meal with at least 8 ounces of water.

References

  1. (2021) "Product Information. Mefloquine Hydrochloride (mefloquine)." Hikma USA (formerly West-Ward Pharmaceutical Corporation)
  2. Schmidt LE, Dalhoff K (2002) "Food-drug interactions." Drugs, 62, p. 1481-502

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Minor

diazePAM food

Applies to: 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 (1986) "Pharmacokinetic and pharmacodynamic interactions between caffeine and diazepam." J Clin Psychopharmacol, 6, p. 75-80

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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.

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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.

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