Dacarbazine Side Effects
Dacarbazine causes severe nausea and vomiting in over 90% of patients, along with potentially life-threatening bone marrow suppression (leukopenia, thrombocytopenia, anemia), and rare but fatal hepatic toxicity including hepatic vein thrombosis and hepatocellular necrosis. 1
Most Common Side Effects (>90% of patients)
Gastrointestinal toxicity is the predominant adverse effect:
- Anorexia, nausea, and vomiting occur in over 90% of patients with initial doses 1
- Vomiting typically lasts 1-12 hours and is incompletely controlled by phenobarbital or prochlorperazine
- Symptoms usually subside after the first 1-2 days, suggesting a central nervous system mechanism
- Rarely, intractable nausea/vomiting necessitates treatment discontinuation
- Diarrhea occurs rarely 1
Clinical tip: Restrict oral food intake for 4-6 hours before treatment to minimize GI symptoms 1
Serious and Life-Threatening Toxicities
Hemopoietic depression is the most common serious toxicity 1:
- Primarily affects leukocytes and platelets
- Anemia may also occur
- Leukopenia and thrombocytopenia can be severe enough to cause death 1
- Requires careful monitoring of complete blood counts
- May warrant temporary suspension or permanent cessation of therapy 1
- Animal studies show dose-related myelosuppression with doses >1380 mg/m² 2, 3
Hepatic toxicity (incidence ~0.01%):
- Hepatic vein thrombosis and hepatocellular necrosis resulting in death 1
- Occurs most commonly when combined with other antineoplastic drugs, but also reported with dacarbazine monotherapy 1
- Moderate hepatitis observed in animal studies 2
Anaphylaxis can occur following administration 1
Moderate Frequency Side Effects
Flu-like syndrome:
- Fever up to 39°C, myalgias, and malaise 1
- Usually occurs after large single doses
- May last several days and recur with successive treatments 1
Dermatologic reactions:
- Alopecia 1
- Erythematous and urticarial rashes (infrequent) 1
- Photosensitivity reactions (rare but important) 1, 3
- Facial flushing and facial paresthesia 1
Pulmonary toxicity (specific context):
- Critical warning: When dacarbazine is used in ABVD regimen (doxorubicin, bleomycin, vinblastine, dacarbazine) for Hodgkin lymphoma, there is increased risk of bleomycin pulmonary toxicity with concurrent G-CSF use 4
- Severe pneumonia observed in animal studies 2
Less Common Side Effects
- Headache 3
- Acute diarrhea 3
- Liver and renal function test abnormalities (infrequent in humans, more common in animal studies) 1
Important Caveats
Hypotension may be dose-limiting at high doses (>1380 mg/m²), potentially secondary to citric acid in the pharmaceutical preparation 3
Comparative toxicity: When compared to temozolomide, dacarbazine shows similar hematologic toxicity except for significantly less lymphopenia (RR 0.26 for dacarbazine vs temozolomide) 5
Monitoring requirements: Close surveillance of white blood cells, red blood cells, and platelet levels is mandatory throughout treatment 1