Dactinomycin (also called actinomycin D) is a chemotherapy medicine. You receive it by IV, often as part of a combination plan. This guide explains key safety points and what to expect.
Brand Name(s)
- United States: Cosmegen [DSC] (discontinued)
- Canada: Cosmegen
Warning(s)
- Low blood counts (bone marrow suppression): This medicine can lower white cells, red cells, and platelets. This raises the risk of infection, anemia, and bleeding. Watch for fever, chills, mouth sores, unusual bruising, bleeding you cannot stop, or extreme tiredness.
- Serious liver injury (veno-occlusive disease): Rare but can be life-threatening. Risk is higher with radiation and in young children. Watch for yellow skin or eyes, dark urine, belly pain, swelling, or sudden weight gain.
- Severe skin reactions: Rare reactions like Stevens–Johnson syndrome/toxic epidermal necrolysis can happen. Get urgent help for a painful red or blistering rash, peeling skin, eye irritation, or sores in the mouth, nose, or eyes.
- Allergic reactions: Hives, rash, wheezing, chest or throat tightness, trouble breathing or swallowing, or swelling of the face, lips, tongue, or throat need emergency care.
- Leakage outside the vein (extravasation): Dactinomycin can severely damage tissue if it leaks from the IV. Tell your nurse right away if you feel burning, pain, swelling, redness, blisters, or fluid leaking at the IV site.
- Kidney problems: Call your care team if you cannot pass urine, notice blood in your urine, pass much less urine, or have sudden swelling or big weight gain.
- Vaccines: Avoid live vaccines while on treatment. Other vaccines may not work as well. Talk with your care team before any shots.
- Radiation sensitivity: This drug can worsen side effects of radiation or trigger “radiation recall” in previously treated areas. Tell your team if you had or will get radiation.
- Pregnancy and birth control: Dactinomycin can harm an unborn baby. You will have a pregnancy test before starting. Use effective birth control during treatment and after the last dose (women: 6 months; men with partners who can become pregnant: 3 months). If pregnancy happens, contact your care team right away. Do not breastfeed during treatment and for 2 weeks after the last dose.
- Second cancers: This medicine may raise the risk of certain later cancers. Your team will monitor you over time.
- Tell every provider you see: Make sure your doctors, nurses, pharmacists, and dentists know you receive dactinomycin. Lab tests and blood counts will be checked regularly.
Kind of Cancers It Is Used For (not a complete list)
- Gestational trophoblastic disease (such as choriocarcinoma or invasive mole)
- Wilms tumor
- Rhabdomyosarcoma
- Soft tissue sarcomas
- Other rare tumors, often as part of combination chemotherapy
Mechanism of Action
Dactinomycin is an antitumor antibiotic. It binds to DNA and blocks the enzyme that makes RNA. This stops cancer cells from making proteins and from dividing. It can also affect healthy fast-growing cells, which is why side effects happen.
Common Side Effects
- Nausea or vomiting
- Decreased appetite or weight loss
- Mouth irritation or sores; a sore throat can make swallowing hard
- Diarrhea or stomach upset
- Hair loss
- Tiredness or weakness
- Skin changes, especially in areas that had radiation (radiation recall)
- Redness, pain, or swelling where the IV goes in
If side effects bother you or do not go away, tell your care team. There are ways to help prevent or ease many of these symptoms.
MedlinePlus: Dactinomycin Injection
Last reviewed: 2025-12-17
