Furmecil Capsules contain a combination of three active components:

• Tegafur (20 mg) – a prodrug that slowly converts into 5-fluorouracil (5-FU), a well-known anti-cancer agent.

• Gimeracil (5.8 mg) – which helps sustain 5-FU levels by inhibiting its breakdown in the body.

• Oteracil (15.8 mg) – which reduces 5-FU activity in the gut, lowering gastrointestinal side effects.

This oral combination allows patients to receive the benefits of 5-FU chemotherapy in a convenient capsule form, often avoiding the need for intravenous infusions. It is commonly known by the international formulation name S-1, used extensively in treating various solid tumours.

Mechanism of Action

Furmecil works through a carefully balanced three-drug mechanism:

1. Tegafur is a slow-release prodrug that gets converted in the liver to 5-fluorouracil (5-FU).

   • 5-FU is incorporated into cancer cell RNA and DNA, disrupting their synthesis and stopping tumour cell growth.

2. Gimeracil inhibits the enzyme dihydropyrimidine dehydrogenase (DPD), which normally breaks down 5-FU.

   • This prolongs and stabilises the active levels of 5-FU in the bloodstream, enhancing anti-cancer effectiveness.

3. Oteracil concentrates in the gut and reduces the activation of 5-FU there, helping protect the intestinal lining and decreasing gastrointestinal toxicity.

   Uses / Indications

   Furmecil is indicated for the treatment of several solid cancers, particularly:

   • Gastric (stomach) cancer, including after surgery to reduce recurrence.

   • Colorectal cancer (colon and rectum), as adjuvant or palliative therapy.

   • Pancreatic cancer, often combined with other agents.

   • Sometimes used in head and neck cancers or non-small cell lung cancer, based on oncologist protocol.

     Adverse Effects

     Furmecil, like most chemotherapy, can cause side effects — though the design of this combination often makes it better tolerated than standard 5-FU infusions.

     Common side effects include:

     • Mild to moderate gastrointestinal upset: nausea, diarrhoea, or reduced appetite.

     • Fatigue, general weakness.

     • Mild skin changes or darkening (hyperpigmentation).

     • Mild decrease in blood counts (anaemia, low white cells or platelets).

     Less common but important side effects:

     • Severe diarrhoea or dehydration, needing prompt fluid management.

     • Mucositis (mouth sores).

     • Rare cardiac effects: such as chest discomfort or changes in heart rhythm with 5-FU family drugs.

     • Hand-foot syndrome (redness, swelling, pain in palms or soles) is less frequent with Furmecil compared to some other fluoropyrimidines, thanks to oteracil.