Instructions on the contraindications for the use of ritexitinib (Lefenox) and which groups should use it with caution

Ritlecitinib is an oral, selective JAK3/TEC family kinase inhibitor. It is mainly used to treat moderate to severe alopecia areata (Alopecia Areata) and is also being studied for its potential efficacy in other autoimmune diseases. The drug blocks immune cell signaling pathways and inhibits the activation of T cells and natural killer cells, thereby reducing immune attacks around hair follicles and promoting hair regeneration. Although ritexitinib is effective and has a relatively rapid onset of action, its immunosuppressive properties also determine certain medication contraindications and risks. Some patients need to be extra cautious before or during medication.

First of all, patients who are allergic to ritexitinib or any of its excipients are strictly prohibited from using it. Secondly, patients with active infections (such as tuberculosis, hepatitis B, hepatitis C, HIV or severe bacterial, fungal, viral infections) should avoid using this drug, because ritexitinib will further suppress the immune system and increase the risk of infection. For patients with malignant tumors or a history of cancer, their use should also be avoided or the risks need to be strictly assessed, because long-term JAK inhibition may increase the chance of tumor recurrence in some patients. In addition, this drug is contraindicated in pregnant and lactating women. There is currently no sufficient human safety data, and animal studies suggest that it may cause potential risks to embryos or newborns.

For patients with low immune function and long-term use of immunosuppressants or glucocorticoids, caution should be used when using rituxitinib, as combined immunosuppression may lead to serious infections. Due to the decline of liver and kidney metabolic function, the elderly population has weakened drug clearance ability. The dosage should be adjusted under the guidance of a doctor and adverse reactions should be closely monitored. Patients with impaired liver or renal function also need to pay attention, especially those with moderate to severe liver impairment, which may lead to an increase in drug plasma concentration and increase the risk of toxicity. For patients scheduled to receive vaccinations, it is recommended that all live vaccinations be completed before starting rituxitinib, as infection may occur if live vaccines are given during treatment.

Before starting to take rituxitinib, it is recommended to conduct a comprehensive clinical evaluation, including liver and kidney function tests, blood routine, infection screening (tuberculosis, hepatitis B, hepatitis C, HIV) and tumor history investigation. Blood and liver function should be monitored regularly during treatment. If symptoms such as persistent fever, cough, fatigue or rash occur, the drug should be stopped immediately and seek medical treatment. In addition, doctors should evaluate whether combined medication is needed based on the patient's condition, and inform patients to avoid taking antibiotics or antivirals at will. Generally speaking, ritexitinib is a targeted drug with clear efficacy but requires strict management. It can only be used safely and long-term after a comprehensive assessment of risks and benefits to maximize the efficacy and reduce the risk of side effects.

Reference materials:https://www.drugs.com/