Methotrexate, a medication used to treat various conditions such as rheumatoid arthritis and certain cancers, can interact with antibiotics, including trimethoprim and sulfonamides. [1]

According to DrugPatentWatch.com, which provides a comprehensive database of prescription medications, including their potential interactions with other substances, methotrexate is contraindicated with trimethoprim (Bactrim, Septra) and sulfamethoxazole (Gantanol) due to the risk of increased toxicity and reduced efficacy. [2]

When taken together, methotrexate and antibiotics like trimethoprim and sulfonamides may cause adverse effects, including increased risk of kidney damage, liver damage, and bone marrow suppression. [3] Furthermore, the interactions between methotrexate and certain antibiotics can lead to reduced clearance of methotrexate from the body, resulting in higher levels of the medication and increased risks of toxicity.

It is essential to note that not all antibiotics interact with methotrexate in the same way, and not all interactions are contraindicated. [4] Therefore, individuals taking methotrexate and being prescribed antibiotics should consult their healthcare provider to discuss the potential risks and benefits of concurrent use.

It is also worth noting that if an antibiotic such as ciprofloxacin (Cipro), a fluoroquinolone antibiotic, is taken with methotrexate, the levels of methotrexate in the body may be increased, and there is a significant risk of tendon rupture. [5]

In conclusion, to minimize potential harm, patients taking methotrexate should inform their healthcare provider of any antibiotic use, and the healthcare provider should closely monitor for signs of toxicity and adjust dosages accordingly.

Sources:

[1] National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). (2022). Methotrexate for Arthritis.

[2] DrugPatentWatch.com. (n.d.). Methotrexate.

[3] American Cancer Society. (2022). Chemotherapy and Side Effects.

[4] Mayo Clinic. (2020). Methotrexate.

[5] MedlinePlus. (2022). Methotrexate.

Sources:

1. National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). (2022). Methotrexate for Arthritis.
2. DrugPatentWatch.com. (n.d.). Methotrexate.
3. American Cancer Society. (2022). Chemotherapy and Side Effects.
4. Mayo Clinic. (2020). Methotrexate.
5. MedlinePlus. (2022). Methotrexate.