Methotrexate and doxycycline interaction: a rare cause of pancytopenia

A critical review of methotrexate clinical interactions: role of transporters

INTRODUCTION

Methotrexate (MTX) is an anti-folate and immunosuppressive drug prescribed for various malignancies and immune diseases. However, delayed elimination of MTX associated with concomitant use of some medications can lead to severe and life-threatening adverse effects.

AREAS COVERED

This paper investigated drug-MTX interactions that lead to elevated MTX levels and related adverse effects due to the role of transporters. Methotrexate toxicity occurs at both low and high doses administrations. According to the studies we reviewed in this paper, most interaction records with methotrexate occurred with co-administration of indomethacin, ketoprofen, omeprazole, piperacillin/tazobactam, ciprofloxacin, co-trimoxazole, probenecid, and imatinib, mainly due to the role of transporters. However, most studies were performed as case reports or series, and confirming the exact drug-methotrexate interaction still needs further clinical investigations.

EXPERT OPINION

Our findings showed no firm evidence of interactions of proton pump inhibitors (PPIs), levetiracetam, and NSAIDS with MTX. Moreover, patients' risk factors, hypoalbuminemia, renal failure, third space fluid retention, the elderly, polypharmacy, and transport inhibition are the most critical factors for MTX toxicity. If substitution or temporary discontinuation is not possible, healthcare providers should be aware of interactions, especially in patients with risk factors for MTX toxicity.

[Medications when travelling with underlying inflammatory rheumatic disease]

Travelling poses particular challenges for patients with rheumatic diseases. This article provides specific guidance on how best to manage medication while away from home. Besides outlining advice on basic logistic issues, such as the transportation, importation and storage of drugs, the article concentrates on travelling while receiving immunosuppressive therapy and carrying narcotics. Especially when transporting narcotics, travel requires careful planning in advance in close collaboration with physicians on account of the strict and internationally diverse import restrictions on controlled substances. While travelling, all drugs should be kept in the original packaging, including the package insert and stored in carry-on luggage. A specific medical passport may be needed. Immunosuppressive and narcotic drugs require medical certificates issued by the prescribing physician, which may need to be certified by the responsible national agencies. Patients receiving glucocorticoid treatment who travel in or across multiple time zones should also be aware of how the medication impacts and interacts with circadian rhythms so as to optimize the anti-inflammatory effects of the drugs and to avoid unnecessary complications. Given the significant discrepancies in medical care and availability of medication worldwide, the article further stresses the importance of a comprehensive medical kit tailored to the patient's individual medicinal needs. Finally, as immunocompromised travellers are at increased risk of infections, advice is given on the use of anti-infective drugs and chemoprophylaxis for patients travelling to areas in which malaria is endemic as well as on their possible interactions with immunosuppressive treatment.