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Drug Interactions between ampicillin / probenecid and famotidine

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 (6)
  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
Minor

probenecid famotidine

Applies to: ampicillin / probenecid and famotidine

Probenecid may inhibit the tubular secretion of famotidine and thereby increase its pharmacologic effects. The clinical significance of this interaction is uncertain.

References (1)
  1. Inotsume N, Nishimura M, Nakano M, Fujiyama S, Sato T (1990) "The inhibitory effect of probenecid on renal excretion of famotidine in young, healthy volunteers." J Clin Pharmacol, 30, p. 50-6

Drug and food/lifestyle interactions

Moderate

ampicillin food/lifestyle

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 (6)
  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
Minor

famotidine food/lifestyle

Applies to: famotidine

H2 antagonists may reduce the clearance of nicotine. Cimetidine, 600 mg given twice a day for two days, reduced clearance of an intravenous nicotine dose by 30%. Ranitidine, 300 mg given twice a day for two days, reduced clearance by 10%. The clinical significance of this interaction is not known. Patients should be monitored for increased nicotine effects when using the patches or gum for smoking cessation and dosage adjustments should be made as appropriate.

References (1)
  1. Bendayan R, Sullivan JT, Shaw C, Frecker RC, Sellers EM (1990) "Effect of cimetidine and ranitidine on the hepatic and renal elimination of nicotine in humans." Eur J Clin Pharmacol, 38, p. 165-9

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.