Muphoran (Fotemustine)

• Fotemustine, a nitrosourea alkylating agent, is employed in oncology to target rapidly proliferating malignant cells, particularly in aggressive skin cancers and high‑grade brain tumors where standard therapies have limited efficacy.
• Malignant melanoma: used in adult patients with advanced or metastatic melanoma, aiming to slow disease progression and extend survival when conventional therapies are insufficient.
• High‑grade glioma: administered to adults with newly diagnosed or recurrent high‑grade glioma, often in combination with radiotherapy, to enhance tumor control and potentially improve overall outcomes.

• Fotemustine exerts its antineoplastic activity by transferring chloroethyl groups to the O6 position of guanine residues in DNA, producing interstrand cross‑links that obstruct DNA replication and transcription. The resulting DNA damage triggers cell‑cycle arrest and apoptosis in rapidly dividing tumor cells, while sparing most normal tissues due to limited repair capacity. Additionally, the alkylation interferes with RNA synthesis, further compromising tumor cell viability.

Fotemustine may cause a range of adverse reactions, varying from mild to severe, that require monitoring during therapy.

Common Side Effects

• Nausea and vomiting: frequent gastrointestinal upset during or after infusion, often managed with antiemetics.
• Myelosuppression: lowered blood cell production causing anemia, neutropenia or thrombocytopenia, increasing infection or bleeding risk.
• Fatigue: persistent tiredness that may limit daily activities and affect quality of life.
• Elevated liver enzymes: temporary rise in transaminases indicating hepatic stress, usually reversible after treatment.

Serious or Rare Side Effects

• Pulmonary fibrosis: progressive scarring of lung tissue that can impair breathing and may be life‑threatening.
• Severe infection: opportunistic bacterial, fungal or viral infections arising from profound neutropenia and immune suppression.
• Renal toxicity: decline in kidney function shown by increased serum creatinine, requiring monitoring and possible dose adjustment.

When using Fotemustine, careful monitoring and specific precautions help minimize risks and ensure safe administration.

• Baseline blood tests: obtain complete blood count and liver function tests before initiating therapy.
• Monitor hematology: perform regular CBCs to detect anemia, neutropenia or thrombocytopenia during treatment.
• Assess liver function: repeat transaminase measurements periodically to identify hepatic toxicity early.
• Evaluate pulmonary status: conduct baseline and periodic lung function assessments, especially in patients with pre‑existing respiratory disease.
• Contraindications: avoid use in patients with known hypersensitivity to nitrosoureas or severe organ dysfunction.
• Store at ambient temperature: keep vials below 25°C, protected from light and moisture in original packaging.

Fotemustine can interact with several concomitant medicines, altering its efficacy or increasing toxicity.

Major Interactions (Avoid)

• Anticoagulants: concurrent use may increase bleeding tendency because Fotemustine‑induced thrombocytopenia can exacerbate anticoagulant effects.
• Live vaccines: administration during therapy can lead to severe infection due to drug‑induced immunosuppression.
• Other alkylating agents: combining with additional alkylators can cause additive bone‑marrow suppression and heightened hematologic toxicity.

Moderate Interactions (Monitor Closely)

• CYP450 inducers: agents such as rifampicin may lower Fotemustine plasma concentrations, potentially reducing antitumor efficacy.
• Anticonvulsants (e.g., phenytoin): may modify Fotemustine metabolism, requiring closer monitoring of blood counts and liver function.
• NSAIDs: concurrent use may aggravate gastrointestinal irritation and increase risk of ulceration in susceptible patients.