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Drug Interactions between amoxicillin / clarithromycin / omeprazole and Peganone

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

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Interactions between your drugs

Moderate

clarithromycin ethotoin

Applies to: amoxicillin / clarithromycin / omeprazole and Peganone (ethotoin)

MONITOR: Coadministration with phenytoin may reduce the plasma concentrations and antimicrobial efficacy of erythromycin and other macrolide antibiotics. The mechanism is induction of CYP450 3A metabolism by phenytoin. Additionally, plasma concentrations of phenytoin may be increased. One study has suggested that the pharmacokinetic disposition of phenytoin is not significantly altered in patients receiving erythromycin. However, occasional large changes in phenytoin clearance were noted in some patients.

MANAGEMENT: If concomitant use is medically necessary, caution and monitoring for altered efficacy and safety of both medications is recommended.

References

  1. Bachmann K, Schwartz JI, Forney RB Jr, Jauregui L "Single dose phenytoin clearance during erythromycin treatment." Res Commun Chem Pathol Pharmacol 46 (1984): 207-17
  2. Milne RW, Coulthard K, Nation RL, et al. "Lack of effect of erythromycin on the pharmacokinetics of single oral doses of phenytoin." Br J Clin Pharmacol 26 (1988): 330-3
  3. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  4. Canadian Pharmacists Association "e-CPS. http://www.pharmacists.ca/function/Subscriptions/ecps.cfm?link=eCPS_quikLink" (2006):
  5. Cerner Multum, Inc. "Australian Product Information." O 0
View all 5 references

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Moderate

omeprazole ethotoin

Applies to: amoxicillin / clarithromycin / omeprazole and Peganone (ethotoin)

MONITOR: Omeprazole may increase phenytoin serum concentrations and the risk of toxicity. The proposed mechanism is decreased clearance due to omeprazole-mediated inhibition of CYP450 2C19. Omeprazole may interact in a similar manner with other hydantoins. The clinical significance is unknown; however, higher omeprazole doses (more than 40 mg/day) may be more likely to interact.

MANAGEMENT: Clinical and laboratory monitoring may be appropriate whenever omeprazole is added to or withdrawn from therapy with phenytoin. Dosage adjustments may be considered if an interaction is suspected. Patients should be advised to notify their doctor if they experience symptoms of phenytoin toxicity (e.g., drowsiness, visual disturbances, change in mental status, seizures, nausea, or ataxia).

References

  1. Andersson T "Omeprazole drug interaction studies." Clin Pharmacokinet 21 (1991): 195-212
  2. Gugler R, Jensen JC "Omeprazole inhibits oxidative drug metabolism: studies with diazepam and phenytoin in vivo and 7-ethoxycoumarin in vitro." Gastroenterology 89 (1985): 1235-41
  3. Prichard PJ, Walt RP, Kitchingman GK, et al. "Oral phenytoin pharmacokinetics during omeprazole therapy." Br J Clin Pharmacol 24 (1987): 543-5
  4. "Product Information. PriLOSEC (omeprazole)." Merck & Co., Inc (2022):
  5. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  6. Cerner Multum, Inc. "Australian Product Information." O 0
View all 6 references

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Minor

amoxicillin clarithromycin

Applies to: amoxicillin / clarithromycin / omeprazole and amoxicillin / clarithromycin / omeprazole

Although some in vitro data indicate synergism between macrolide antibiotics and penicillins, other in vitro data indicate antagonism. When these drugs are given together, neither has predictable therapeutic efficacy. Data are available for erythromycin, although theoretically this interaction could occur with any macrolide. Except for monitoring of the effectiveness of antibiotic therapy, no special precautions appear to be necessary.

References

  1. Strom J "Penicillin and erythromycin singly and in combination in scarlatina therapy and the interference between them." Antibiot Chemother 11 (1961): 694-7
  2. Cohn JR, Jungkind DL, Baker JS "In vitro antagonism by erythromycin of the bactericidal action of antimicrobial agents against common respiratory pathogens." Antimicrob Agents Chemother 18 (1980): 872-6
  3. Penn RL, Ward TT, Steigbigel RT "Effects of erythromycin in combination with penicillin, ampicillin, or gentamicin on the growth of listeria monocytogenes." Antimicrob Agents Chemother 22 (1982): 289-94

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Minor

clarithromycin omeprazole

Applies to: amoxicillin / clarithromycin / omeprazole and amoxicillin / clarithromycin / omeprazole

Clarithromycin may increase and prolong the omeprazole plasma concentration. The mechanism may be related to clarithromycin inhibition of hepatic cytochrome P450 enzymes responsible for omeprazole metabolism. Coadministration of omeprazole may result in an increase in clarithromycin and 14-(R)-hydroxyclarithromycin plasma concentrations. These increases may be due to the effect of omeprazole on gastric pH.

References

  1. Zhou Q, Yamamoto I, Fukuda T, Ohno M, Sumida A, Azuma J "CYP2C19 genotypes and omeprazole metabolism after single and repeated dosing when combined with clarithromycin." Eur J Clin Pharmacol 55 (1999): 43-7
  2. Gustavson LE, Kaiser JF, Edmonds AL, Locke CS, DeBartolo ML, Schneck DW "Effect of omeprazole on concentrations of clarithromycin in plasma and gastric tissue at steady state." Antimicrob Agents Chemother 39 (1995): 2078-83
  3. Furuta T, Ohashi K, Kobayashi K, Iida I, Yoshida H, Shirai N, Takashima M, Kosuge K, Hanai H, Chiba K, Ishizaki T, Kaneko E "Effects of clarithromycin on the metabolism of omeprazole in relation to CYP2C19 genotype status in humans." Clin Pharmacol Ther 66 (1999): 265-74

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Drug and food interactions

Moderate

ethotoin food

Applies to: Peganone (ethotoin)

ADJUST DOSING INTERVAL: Phenytoin bioavailability may decrease to subtherapeutic levels when the suspension is given concomitantly with enteral feedings. The mechanism may be related to phenytoin binding to substances in the enteral formula (e.g., calcium, protein) and/or binding to the tube lumen. Data have been conflicting and some studies have reported no changes in phenytoin levels, while others have reported significant reductions.

MONITOR: Acute consumption of alcohol may increase plasma phenytoin levels. Chronic consumption of alcohol may decrease plasma phenytoin levels. The mechanism of this interaction is related to induction of phenytoin metabolism by ethanol during chronic administration. Other hydantoin derivatives may be similarly affected by ethanol.

MANAGEMENT: Some experts have recommended interrupting the feeding for 2 hours before and after the phenytoin dose, giving the phenytoin suspension diluted in water, and flushing the tube with water after administration; however, this method may not entirely avoid the interaction and is not always clinically feasible. Patients should be closely monitored for clinical and laboratory evidence of altered phenytoin efficacy and levels upon initiation and discontinuation of enteral feedings. Dosage adjustments or intravenous administration may be required until therapeutic serum levels are obtained. In addition, patients receiving phenytoin therapy should be warned about the interaction between phenytoin and ethanol and they should be advised to notify their physician if they experience worsening of seizure control or symptoms of toxicity, including drowsiness, visual disturbances, change in mental status, nausea, or ataxia.

References

  1. Sandor P, Sellers EM, Dumbrell M, Khouw V "Effect of short- and long-term alcohol use on phenytoin kinetics in chronic alcoholics." Clin Pharmacol Ther 30 (1981): 390-7
  2. Holtz L, Milton J, Sturek JK "Compatibility of medications with enteral feedings." JPEN J Parenter Enteral Nutr 11 (1987): 183-6
  3. Sellers EM, Holloway MR "Drug kinetics and alcohol ingestion." Clin Pharmacokinet 3 (1978): 440-52
  4. "Product Information. Dilantin (phenytoin)." Parke-Davis PROD (2001):
  5. Doak KK, Haas CE, Dunnigan KJ, et al. "Bioavailability of phenytoin acid and phenytoin sodium with enteral feedings." Pharmacotherapy 18 (1998): 637-45
  6. Rodman DP, Stevenson TL, Ray TR "Phenytoin malabsorption after jejunostomy tube delivery." Pharmacotherapy 15 (1995): 801-5
  7. Au Yeung SC, Ensom MH "Phenytoin and enteral feedings: does evidence support an interaction?" Ann Pharmacother 34 (2000): 896-905
  8. Ozuna J, Friel P "Effect of enteral tube feeding on serum phenytoin levels." J Neurosurg Nurs 16 (1984): 289-91
  9. Faraji B, Yu PP "Serum phenytoin levels of patients on gastrostomy tube feeding." J Neurosci Nurs 30 (1998): 55-9
  10. Marvel ME, Bertino JS "Comparative effects of an elemental and a complex enteral feeding formulation on the absorption of phenytoin suspension." JPEN J Parenter Enteral Nutr 15 (1991): 316-8
  11. Fleisher D, Sheth N, Kou JH "Phenytoin interaction with enteral feedings administered through nasogastric tubes." JPEN J Parenter Enteral Nutr 14 (1990): 513-6
  12. Haley CJ, Nelson J "Phenytoin-enteral feeding interaction." DICP 23 (1989): 796-8
  13. Guidry JR, Eastwood TF, Curry SC "Phenytoin absorption in volunteers receiving selected enteral feedings." West J Med 150 (1989): 659-61
  14. Krueger KA, Garnett WR, Comstock TJ, Fitzsimmons WE, Karnes HT, Pellock JM "Effect of two administration schedules of an enteral nutrient formula on phenytoin bioavailability." Epilepsia 28 (1987): 706-12
  15. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  16. Cerner Multum, Inc. "Australian Product Information." O 0
View all 16 references

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Minor

clarithromycin food

Applies to: amoxicillin / clarithromycin / omeprazole

Grapefruit juice may delay the gastrointestinal absorption of clarithromycin but does not appear to affect the overall extent of absorption or inhibit the metabolism of clarithromycin. The mechanism of interaction is unknown but may be related to competition for intestinal CYP450 3A4 and/or absorptive sites. In an open-label, randomized, crossover study consisting of 12 healthy subjects, coadministration with grapefruit juice increased the time to reach peak plasma concentration (Tmax) of both clarithromycin and 14-hydroxyclarithromycin (the active metabolite) by 80% and 104%, respectively, compared to water. Other pharmacokinetic parameters were not significantly altered. This interaction is unlikely to be of clinical significance.

References

  1. Cheng KL, Nafziger AN, Peloquin CA, Amsden GW "Effect of grapefruit juice on clarithromycin pharmacokinetics." Antimicrob Agents Chemother 42 (1998): 927-9

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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.

See also

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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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