Skip to main content

Drug Interactions between Folex PFS and Moxilin

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

Edit list (add/remove drugs)

Interactions between your drugs

Major

methotrexate amoxicillin

Applies to: Folex PFS (methotrexate) and Moxilin (amoxicillin)

MONITOR CLOSELY: Concomitant use of large doses of penicillins may elevate serum methotrexate concentrations. The mechanism may involve competitive inhibition of renal tubular secretion of methotrexate. In one study, methotrexate clearance reductions were 35%, 40%, and 66% with penicillin, ticarcillin, and piperacillin, respectively. Serious adverse effects, primarily hematologic, have been described with concurrent penicillins and high or low-dose methotrexate regimens. Fatalities have occurred with both types of methotrexate regimens.

MANAGEMENT: If a penicillin must be used concurrently, close monitoring of methotrexate serum concentrations and of the patient for evidence of serious methotrexate toxicity are recommended. Leucovorin rescue should be available. Methotrexate dose reductions may be necessary. If broad-spectrum antibiotic coverage is needed during high-dose methotrexate therapy, use of other antimicrobials may be preferable. Patients should be advised to promptly report symptoms including fever, chills, sore throat, bruising, bleeding, stomatitis, or malaise to their physician.

References

  1. Bloom EJ, Ignoffo RJ, Reis CA, Cadman E "Delayed clearance (CL) of methotrexate (MTX) associated with antibiotics and antiinflammatory agents." Clin Res 34 (1986): a560
  2. Nierenberg DW, Mamelok RD "Toxic reaction to methotrexate in a patient receiving penicillin and furosemide: a possible interaction." Arch Dermatol 119 (1983): 449-50
  3. Mayall B, Poggi G, Parkin JD "Neutropenia due to low-dose methotrexate therapy for psoriasis and rheumatoid arthritis may be fatal." Med J Aust 155 (1991): 480-4
  4. "Product Information. Methotrexate (methotrexate)." Lederle Laboratories PROD (2002):
  5. "Product Information. Zosyn (piperacillin-tazobactam)." Lederle Laboratories PROD (2001):
  6. Ronchera CL, Hernandez T, Peris JE, Torres F, et al. "Pharmacokinetic interaction between high-dose methotrexate and amoxycillin." Ther Drug Monit 15 (1993): 375-9
  7. "Product Information. Methotrexate (methotrexate)." Lederle Laboratories PROD
  8. Yamamoto K, Sawada Y, Matsushita Y, Moriwaki K, Bessho F, Iga T "Delayed elimination of methotrexate associated with piperacillin administration." Ann Pharmacother 31 (1997): 1261-2
  9. Dean R, Nachman J, Lorenzana AN "Possible methotrexate-mezlocillin interaction." Am J Pediatr Hematol Oncol 14 (1992): 88-92
  10. Titier K, Lagrange F, Pehourcq F, Moore N, Molimard M "Pharmacokinetic interaction between high-dose methotrexate and oxacillin." Ther Drug Monit 24 (2002): 570-2
View all 10 references

Switch to consumer interaction data

Drug and food interactions

Moderate

methotrexate food

Applies to: Folex PFS (methotrexate)

MONITOR: Limited data suggest that consumption of greater than 180 mg/day of caffeine may interfere with the efficacy of methotrexate (MTX) in patients with rheumatoid arthritis. The exact mechanism of interaction is unknown but may be related to the antagonistic effect of caffeine on adenosine receptors, as anti-inflammatory properties of MTX is thought to result from the accumulation of adenosine. In a study of 39 patients treated with MTX 7.5 mg/week (without folate supplementation) for 3 months, patients with high caffeine intake (more than 180 mg/day) experienced significantly less improvement in morning stiffness and joint pain from baseline than patients with low caffeine intake (less than 120 mg/day). There were no significant differences between the responses of patients with moderate caffeine intake (120 to 180 mg/day) and those of the other 2 groups. In an interview of 91 patients treated with MTX, 26% of patients who discontinued the drug were regular coffee drinkers compared to only 2% of those still receiving the drug. Because treatment failure was the reason for MTX discontinuation in 80% of patients who discontinued, the investigators suggested that caffeine may have interfered with MTX efficacy.

MANAGEMENT: Until further information is available, the potential for interaction should be considered in patients who consume substantial amounts of caffeine and caffeine-containing foods and are prescribed methotrexate for rheumatoid arthritis. It may be appropriate to limit caffeine intake if an interaction is suspected in cases of treatment failure.

References

  1. Nesher G, Mates M, Zevin S "Effect of caffeine consumption on efficacy of methotrexate in rheumatoid arthritis." Arthritis Rheum 48 (2003): 571-572

Switch to consumer interaction data

Moderate

methotrexate food

Applies to: Folex PFS (methotrexate)

GENERALLY AVOID: Coadministration of methotrexate with other agents known to induce hepatotoxicity may potentiate the risk of liver injury. Methotrexate, especially at higher dosages or during prolonged treatment, has been associated with severe hepatotoxicity including acute hepatitis, chronic fibrosis, cirrhosis, and fatal liver failure.

MANAGEMENT: The risk of hepatic injury should be considered when methotrexate is used with other potentially hepatotoxic agents (e.g., acetaminophen; alcohol; androgens and anabolic steroids; antituberculous agents; azole antifungal agents; ACE inhibitors; cyclosporine (high dosages); disulfiram; endothelin receptor antagonists; interferons; ketolide and macrolide antibiotics; kinase inhibitors; minocycline; nonsteroidal anti-inflammatory agents; nucleoside reverse transcriptase inhibitors; proteasome inhibitors; retinoids; sulfonamides; tamoxifen; thiazolidinediones; tolvaptan; vincristine; zileuton; anticonvulsants such as carbamazepine, hydantoins, felbamate, and valproic acid; lipid-lowering medications such as fenofibrate, lomitapide, mipomersen, niacin, and statins; herbals and nutritional supplements such as black cohosh, chaparral, comfrey, DHEA, kava, pennyroyal oil, and red yeast rice). Baseline and periodic monitoring of hepatic function is recommended, while liver biopsy may be warranted during long-term use of methotrexate. Patients should be advised to seek medical attention if they experience potential signs and symptoms of hepatotoxicity such as fever, rash, itching, anorexia, nausea, vomiting, fatigue, right upper quadrant pain, dark urine, pale stools, and jaundice.

References

  1. "Product Information. Methotrexate (methotrexate)." Lederle Laboratories PROD (2002):
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  3. "Product Information. Methotrexate (methotrexate)." Hospira Inc (2023):

Switch to consumer interaction data

Moderate

methotrexate food

Applies to: Folex PFS (methotrexate)

MONITOR: Limited data suggest that consumption of greater than 180 mg/day of caffeine may interfere with the efficacy of methotrexate (MTX) in patients with rheumatoid arthritis. The exact mechanism of interaction is unknown but may be related to the antagonistic effect of caffeine on adenosine receptors, as anti-inflammatory properties of MTX is thought to result from the accumulation of adenosine. In a study of 39 patients treated with MTX 7.5 mg/week (without folate supplementation) for 3 months, patients with high caffeine intake (more than 180 mg/day) experienced significantly less improvement in morning stiffness and joint pain from baseline than patients with low caffeine intake (less than 120 mg/day). There were no significant differences between the responses of patients with moderate caffeine intake (120 to 180 mg/day) and those of the other 2 groups. In an interview of 91 patients treated with MTX, 26% of patients who discontinued the drug were regular coffee drinkers compared to only 2% of those still receiving the drug. Because treatment failure was the reason for MTX discontinuation in 80% of patients who discontinued, the investigators suggested that caffeine may have interfered with MTX efficacy.

MANAGEMENT: Until further information is available, the potential for interaction should be considered in patients who consume substantial amounts of caffeine and caffeine-containing foods and are prescribed methotrexate for rheumatoid arthritis. It may be appropriate to limit caffeine intake if an interaction is suspected in cases of treatment failure.

References

  1. Nesher G, Mates M, Zevin S "Effect of caffeine consumption on efficacy of methotrexate in rheumatoid arthritis." Arthritis Rheum 48 (2003): 571-572

Switch to consumer interaction data

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

Report options

Loading...
QR code containing a link to this page

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.

Medical Disclaimer