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penicillin G benzathine intramuscular


This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.

Medical warning:

Moderate. These medicines may cause some risk when taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

How the interaction occurs:

When these two medicines are taken together, penicillin may react with your aminoglycoside and cause the aminoglycoside to be less effective in treating your infection.

What might happen:

The beneficial effect of the aminoglycoside antibiotic may be decreased.

What you should do about this interaction:

Do not combine these antibiotics in the same intravenous solution.Tell your doctor if you now have kidney problems. This may put you at greater risk for this interaction.Make sure that your doctor knows all of the medicines that you are taking.Your healthcare professionals (e.g. doctor or pharmacist) may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.


1.Davies M, Morgan JR, Anand C. Interactions of carbenicillin and ticarcillin with gentamicin. Antimicrob Agents Chemother 1975 Apr; 7(4):431-4.
2.Riff LJ, Jackson GG. Laboratory and clinical conditions for gentamicin inactivation by carbenicillin. Arch Intern Med 1972 Dec;130(6):887-91.
3.Thompson MI, Russo ME, Saxon BJ, Atkin-Thor E, Matsen JM. Gentamicin inactivation by piperacillin or carbenicillin in patients with end-stage renal disease. Antimicrob Agents Chemother 1982 Feb;21(2):268-73.
4.Matzke GR, Halstenson CE, Heim KL, Abraham PA, Keane WF. Netilmicin disposition is not altered by concommitant piperacillin administration. Clin Pharmacol Ther 1985 Feb;37(2):210.
5.Viollier AF, Standiford HC, Drusano GL, Tatem BA, Moody MR, Schimpff SC. Comparative pharmacokinetics and serum bactericidal activity of mezlocillin, ticarcillin and piperacillin, with and without gentamicin. J Antimicrob Chemother 1985 May;15(5):597-606.
6.Fuursted K. Comparison of the post-antibiotic effect of Streptococcus faecalis and Streptococcus faecium with ampicillin alone or combined with streptomycin: studies on a novel type of antimicrobial interaction. Acta Pathol Microbiol Immunol Scand B 1987 Dec;95(6):351-4.
7.Lorian V, Ernst J. Activity of amikacin and ampicillin in succession and in combination. Diagn Microbiol Infect Dis 1988 Nov;11(3):163-9.
8.Bingen E, Lambert-Zechovsky N, Aujard Y, Mariani P, Lemer G, Sauzeau C, Mathieu H. Early synergistic killing activity at concentrations attainable in CSF of amoxicillin or cefotaxime and aminoglycosides against Haemophilus influenzae. Infection 1988 Mar-Apr;16(2):121-5.
9.Halstenson CE, Hirata CA, Heim-Duthoy KL, Abraham PA, Matzke GR. Effect of concomitant administration of piperacillin on the dispositions of netilmicin and tobramycin in patients with end-stage renal disease. Antimicrob Agents Chemother 1990 Jan;34(1):128-33.
10.Uber WE, Brundage RC, White RL, Brundage DM, Bromley HR. In vivo inactivation of tobramycin by piperacillin. DICP 1991 Apr;25(4):357-9.
11.Roberts GW, Nation RL, Jarvinen AO, Martin AJ. An in vivo assessment of the tobramycin/ticarcillin interaction in cystic fibrosis patients. Br J Clin Pharmacol 1993;36:372-5.

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