Drug Interactions between allopurinol and ampicillin / probenecid
This report displays the potential drug interactions for the following 2 drugs:
- allopurinol
- ampicillin/probenecid
Interactions between your drugs
ampicillin allopurinol
Applies to: ampicillin / probenecid and allopurinol
Coadministration of allopurinol with ampicillin or amoxicillin may increase the risk of skin rash. The mechanism of interaction is unknown, and it is unclear whether the condition of hyperuricemia or the actual exposure to allopurinol is responsible. In a retrospective study, 15 out of 67 patients (22%) who took ampicillin with allopurinol developed a skin rash, compared to 94 out of 1257 patients (7.5%) who took ampicillin without allopurinol. An updated study by the same group of investigators consisted of 252 patients who took ampicillin with allopurinol and 4434 who took ampicillin alone. The incidence of rash was 13.9% in the allopurinol group and 5.7% in the ampicillin-only group. Similar results were reported for amoxicillin. Specifically, 8 out of 36 patients (22%) treated concomitantly with allopurinol developed a rash, compared to 52 out of 887 patients (5.9%) on amoxicillin without allopurinol. There is probably no need to avoid concomitant use of these drugs in patients who otherwise can take these drugs individually.
References
- Singer JZ, Wallace SL (1986) "The allopurinol hypersensitivity syndrome." Arthritis Rheum, 29, p. 82-7
- Boston Collaborative Drug Surveillance Program (1972) "Excess of ampicillin rashes associated with allopurinol or hyperuricemia." N Engl J Med, 286, p. 505-7
- (2022) "Product Information. Zyloprim (allopurinol)." Glaxo Wellcome
- Jick H, Porter JB (1981) "Potentiation of ampicillin skin reactions by allopurinol or hyperuricemia." J Clin Pharmacol, 21, p. 456-8
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
- Sommers DK, Schoeman HS (1987) "Drug interactions with urate excretion in man?" Eur J Clin Pharmacol, 32, p. 499-502
- Waller ES, Sharanevych MA, Yakatan GJ (1982) "The effect of probenecid on nafcillin disposition." J Clin Pharmacol, 22, p. 482-9
- 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
- Sutherland R, Croydon EA, Rolinson GN (1972) "Amoxycillin: a new semi-synthetic penicillin." Br Med J, 3, p. 13-6
- 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
- Gibaldi M, Schwartz MA (1968) "Apparent effect of probenecid on the distribution of penicillins in man." Clin Pharmacol Ther, 9, p. 345-9
allopurinol probenecid
Applies to: allopurinol and ampicillin / probenecid
Probenecid may increase the renal excretion of oxypurinol, the active metabolite of allopurinol, while allopurinol may inhibit probenecid metabolism. The clinical significance is unknown. Patients should be monitored for altered effects of both drugs.
References
- Elion GB, Yu TF, Gutman AB, Hitchings GH (1968) "Renal clearance of oxipurinol, the chief metabolite of allopurinol." Am J Med, 45, p. 69-77
- Tjandramaga TB, Cucinell SA, Israili ZH, et al. (1972) "Observations on the disposition of probenecid in patients receiving allopurinol." Pharmacology, 8, p. 259-72
- Kelley WN (1976) "Current therapy of gout and hyperuricemia." Hosp Pract, 11, p. 69-76
Drug and food interactions
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
- Neu HC (1974) "Antimicrobial activity and human pharmacology of amoxicillin." J Infect Dis, 129, s123-31
- 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
- McCarthy CG, Finland M (1960) "Absorption and excretion of four penicillins." N Engl J Med, 263, p. 315-26
- 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
- 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
- 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
Therapeutic duplication warnings
Therapeutic duplication is the use of more than one medicine from the same drug category or therapeutic class to treat the same condition. This can be intentional in cases where drugs with similar actions are used together for demonstrated therapeutic benefit. It can also be unintentional in cases where a patient has been treated by more than one doctor, or had prescriptions filled at more than one pharmacy, and can have potentially adverse consequences.
Anti-gout agents
Therapeutic duplication
The recommended maximum number of medicines in the 'anti-gout agents' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'anti-gout agents' category:
- allopurinol
- ampicillin/probenecid
Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.
See also
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
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. | |
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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