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Drug Interactions between ampicillin / probenecid and rifampin

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

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Interactions between your drugs

Minor

ampicillin probenecid

Applies to: ampicillin / probenecid and ampicillin / probenecid

Probenecid may increase the plasma concentrations and half-lives of penicillins. The mechanism is competitive inhibition by probenecid of the renal tubular secretion of penicillins. While this interaction is often exploited to enhance the antibacterial effect of penicillins, toxicity may occur and should be considered if high penicillin dosages are administered intravenously.

References

  1. Sommers DK, Schoeman HS (1987) "Drug interactions with urate excretion in man?" Eur J Clin Pharmacol, 32, p. 499-502
  2. Waller ES, Sharanevych MA, Yakatan GJ (1982) "The effect of probenecid on nafcillin disposition." J Clin Pharmacol, 22, p. 482-9
  3. Shanson DC, McNabb R, Hajipieris P (1984) "The effect of probenecid on serum amoxycillin concentrations up to 18 hours after a single 3g oral dose of amoxycillin: possible implications for preventing endocarditis." J Antimicrob Chemother, 13, p. 629-32
  4. Sutherland R, Croydon EA, Rolinson GN (1972) "Amoxycillin: a new semi-synthetic penicillin." Br Med J, 3, p. 13-6
  5. Allen MB, Fitzpatrick RW, Barratt A, Cole RB (1990) "The use of probenecid to increase the serum amoxycillin levels in patients with bronchiectasis." Respir Med, 84, p. 143-6
  6. Gibaldi M, Schwartz MA (1968) "Apparent effect of probenecid on the distribution of penicillins in man." Clin Pharmacol Ther, 9, p. 345-9
View all 6 references

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Minor

probenecid rifAMPin

Applies to: ampicillin / probenecid and rifampin

Probenecid may increase serum concentrations of rifampin, possibly by impairing hepatic uptake of rifampin. This effect appears to be inconsistent, occurring in some patients, but not in others.

References

  1. Venkatesan K (1992) "Pharmacokinetic drug interactions with rifampicin." Clin Pharmacokinet, 22, p. 47-65
  2. Kenwright S, Levi AJ (1973) "Impairment of hepatic uptake of rifamycin antibiotics by probenicid, and its therapeutic implications." Lancet, 21, p. 1401-5
  3. Allen BW, Ellard GA, Mitchison DA, Hatfield AR, Kenwright S, Levi AJ (1975) "Probenecid and serum-rifampicin." Lancet, 2, p. 1309
  4. Fallon RJ, Allan GW, Lees AW, Smith J, Tyrrell WF (1975) "Probenecid and rifampicin serum levels." Lancet, 2, p. 792-4
View all 4 references

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Drug and food interactions

Moderate

ampicillin food

Applies to: ampicillin / probenecid

ADJUST DOSING INTERVAL: Certain penicillins may exhibit reduced gastrointestinal absorption in the presence of food. The therapeutic effect of the antimicrobial may be reduced.

MANAGEMENT: The interacting penicillin should be administered one hour before or two hours after meals. Penicillin V and amoxicillin are not affected by food and may be given without regard to meals.

References

  1. Neu HC (1974) "Antimicrobial activity and human pharmacology of amoxicillin." J Infect Dis, 129, s123-31
  2. Welling PG, Huang H, Koch PA, Madsen PO (1977) "Bioavailability of ampicillin and amoxicillin in fasted and nonfasted subjects." J Pharm Sci, 66, p. 549-52
  3. McCarthy CG, Finland M (1960) "Absorption and excretion of four penicillins." N Engl J Med, 263, p. 315-26
  4. Cronk GA, Wheatley WB, Fellers GF, Albright H (1960) "The relationship of food intake to the absorption of potassium alpha-phenoxyethyl penicillin and potassium phenoxymethyl penicillin from the gastrointestinal tract." Am J Med Sci, 240, p. 219-25
  5. Klein JO, Sabath LD, Finland M (1963) "Laboratory studies on oxacillin. I: in vitro activity against staphylococci and some other bacterial pathogens. II: absorption and urinary excretion in normal young." Am J Med Sci, 245, p. 399-411
  6. Neuvonen PJ, Elonen E, Pentikainen PJ (1977) "Comparative effect of food on absorption of ampicillin and pivampicillin." J Int Med Res, 5, p. 71-6
View all 6 references

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Moderate

rifAMPin food

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

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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.