Carboplatin (Paraplatin)

Overview

Carboplatin is a second-generation platinum-based chemotherapy drug that is less nephrotoxic and neurotoxic than cisplatin. It forms DNA cross-links that inhibit DNA synthesis and trigger apoptosis. Carboplatin is commonly used in combination regimens for various solid tumors.

Key Features

• Better tolerated than cisplatin with less nausea, nephrotoxicity, and neurotoxicity
• Dosed based on AUC (area under the curve) using Calvert formula
• Primary toxicity is myelosuppression, particularly thrombocytopenia
• Can be given in outpatient setting
• No prehydration required unlike cisplatin

FDA-Approved Indications

Labeled Indications

• Advanced Ovarian Cancer:
  • First-line in combination with other approved chemotherapy
  • Recurrent disease after prior chemotherapy, including prior cisplatin

Ovarian cancer is the only use listed in the FDA label. Off-label use is common and does not mean the treatment is unproven. It means the use is not listed in the label.

Common Off-Label Uses

• Non-small cell lung cancer (with paclitaxel or pemetrexed)
• Small cell lung cancer (with etoposide)
• Breast cancer (triple-negative)
• Head and neck cancers
• Bladder cancer
• Testicular cancer
• Endometrial cancer
• Cervical cancer
• Malignant gliomas
• Retinoblastoma
• Neuroblastoma

Mechanism of Action

Carboplatin is a platinum coordination compound that acts as an alkylating agent:

1. Activation: Undergoes hydrolysis to form active platinum complexes
2. DNA Binding: Forms covalent bonds with nucleophilic sites on DNA bases (primarily guanine N7)
3. Cross-link Formation: Creates intrastrand and interstrand DNA cross-links
4. Cell Cycle Arrest: Prevents DNA replication and transcription
5. Apoptosis: Triggers programmed cell death pathways

Resistance Mechanisms

• Decreased drug accumulation (reduced uptake/increased efflux)
• Increased DNA repair (nucleotide excision repair)
• Increased glutathione and metallothionein levels
• Defects in apoptotic pathways

Pharmacology

Pharmacokinetics

• Distribution: Vd = 16 L; carboplatin itself is not bound to plasma proteins, but platinum from it binds irreversibly, with a minimum half-life of 5 days
• Metabolism: Minimal hepatic metabolism; undergoes hydrolysis
• Elimination: Primarily renal (about 71% in 24 hours with creatinine clearance of 60 mL/min or more)
• Half-life: Initial 1.1-2 hours; post-distribution 2.6-5.9 hours (longer with renal impairment)
• Clearance: Correlates with GFR

Special Populations

• Renal Impairment: Dose adjustment required (use Calvert formula)
• Hepatic Impairment: No specific adjustment needed
• Elderly: May require dose reduction due to decreased renal function
• Pregnancy: Category D - can cause fetal harm

Dosing and Administration

Calvert Formula for AUC-Based Dosing

Common Dosing Regimens

Dose Modifications

• Before the next cycle: The label says not to repeat treatment until neutrophils are at least 2,000/mm³ and platelets are at least 100,000/mm³
• Lowest counts of platelets below 50,000/mm³ or neutrophils below 500/mm³: Label suggests 75% of the prior dose. Doses of 50-60% were used in trials for severe low counts
• CrCl 41-59 mL/min: Fixed starting dose of 250 mg/m² in the label, or use the Calvert formula
• CrCl 16-40 mL/min: Fixed starting dose of 200 mg/m² in the label, or use the Calvert formula
• CrCl 15 mL/min or less: The label says data are too limited to guide dosing

AUC Dosing in Plain Words

Many chemotherapy drugs are dosed by body size. Carboplatin is usually dosed by kidney function. This is because the kidneys remove most of the drug. About 71% leaves in the urine within 24 hours when kidney function is good.

AUC stands for "area under the curve." Picture a graph of the drug level in your blood over time. The level rises, then falls as your kidneys clear the drug. The area under that line shows your total exposure to the drug. A higher AUC means more exposure.

Your oncologist first picks a target, such as AUC 5. The Calvert formula then turns that target into a dose in milligrams, using your GFR. GFR is a measure of how well your kidneys filter blood. It is usually estimated from a blood creatinine test, along with your age, weight, and sex.

What This Means for You

• Your dose may change between cycles if your creatinine, weight, or other results change
• Muscle loss or a very low creatinine can make kidney function look better than it is, so your team may adjust the calculation
• Tell your team if you are dehydrated, have started a new kidney-affecting medicine, or have had vomiting or diarrhea before a dose
• Your AUC number is a target, not a score for how strong your treatment is. The right target depends on the regimen and your prior treatment

Side Effects

Serious Adverse Events

• Severe myelosuppression: Can be life-threatening
• Hypersensitivity reactions: Risk increases with multiple cycles
• Tumor lysis syndrome: In sensitive tumors
• Posterior reversible encephalopathy syndrome: Rare

Nadir: When Blood Counts Are Lowest

Carboplatin slows the bone marrow, which makes blood cells. Counts fall for a time after each dose and then recover. The lowest point is called the nadir. For many chemotherapy drugs it comes about 7 to 10 days after treatment. Carboplatin alone is later.

That is why single-agent carboplatin is often given every 4 weeks. When it is combined with other drugs, the timing and depth can differ, and cycles are often 3 weeks. Ask your team which days to watch closely.

How Low Counts Can Go

These figures come from ovarian cancer studies in the label. Low platelets are a main concern with carboplatin.

What to Do Around the Nadir

• Know your emergency number. Treat a temperature of 100.4°F (38°C) or higher as urgent, and read our guide to fever during chemotherapy
• Report nosebleeds, bleeding gums, new bruises, tiny red spots on the skin, or black stools
• Ask before taking aspirin or other NSAIDs, which can add to bleeding risk
• Avoid people who are sick and wash your hands often

See our guide to blood counts to understand your results.

Allergic Reactions After Many Cycles

Carboplatin can cause allergic reactions. These are unusual early on, and they become more likely with repeated doses. This pattern can surprise people who have had many easy treatments.

Who Is at Risk

• In the label's studies, 2% of people on carboplatin alone had a reaction and 11% on combination treatment did
• Published reports range from 1% to 35%, depending on the group studied
• Reactions are more common when carboplatin is used again for a return of ovarian cancer, with a peak around a median of seven cycles
• The risk rises with each further cycle
• A long gap of more than 12 months since the last platinum drug was linked to more reactions in one report

What It Feels Like

• Mild: Flushing, rash, itching, sweating, face swelling, fever, chills, nausea, or backache
• Severe: Trouble breathing, wheezing, chest pain, a pounding or fast heartbeat, a change in blood pressure, fainting, or throat swelling

Reactions can start within minutes of the infusion. Most occur within the first hour, but some are delayed by hours to days.

If You Have Had a Reaction

• A history of severe allergy to carboplatin, cisplatin, or other platinum drugs is a contraindication in the label
• Your team will weigh how severe the reaction was, how well carboplatin has worked, and your other options
• Giving it again in the usual way carries a high risk of another severe reaction
• Some centers use desensitization, with very slow, stepwise dosing and close monitoring. This should be done only by an experienced team
• Skin tests may help assess the risk, but they do not predict how severe a reaction would be
• Another drug may be chosen. About 1 in 5 people who switch to cisplatin later react to it, so this also needs care

Contraindications & Warnings

Absolute Contraindications

• Severe hypersensitivity to carboplatin or platinum compounds
• Severe bone marrow suppression
• Significant bleeding

Warnings and Precautions

• Bone Marrow Suppression: Monitor blood counts closely
• Hypersensitivity: Risk increases after 6+ cycles
• Renal Toxicity: Less than cisplatin but still monitor
• Hepatotoxicity: Monitor liver function
• Pregnancy: Effective contraception required
• Fertility: May cause infertility in both sexes

Use with Caution

• Renal impairment (adjust dose)
• Hearing impairment
• Prior radiation therapy
• Elderly patients
• Prior platinum therapy

Drug Interactions

Monitoring Parameters

Periodic Monitoring

• Weekly during nadir: CBC if severe myelosuppression
• As indicated: Audiometry if ototoxicity suspected
• Long-term: Monitor for secondary malignancies

Hypersensitivity Monitoring

• Observe closely during infusion, especially after cycle 6
• Have emergency medications readily available
• Consider skin testing if prior reaction

Administration Guide

Preparation

• Available as 50mg, 150mg, 450mg, 600mg vials
• Dilute in D5W or NS to concentration 0.5-2 mg/mL
• Stable for 8 hours at room temperature after dilution
• Do not use aluminum-containing equipment
• Use within 8 hours of preparation

Administration

• Route: IV infusion only
• Duration: Typically 15-60 minutes
• Premedications:
  • Antiemetics (5-HT3 antagonist + dexamethasone)
  • Consider H1/H2 blockers after multiple cycles
• Hydration: Not required (unlike cisplatin)

Extravasation Management

• Carboplatin is an irritant, not a vesicant
• Stop infusion immediately
• Aspirate residual drug
• Apply ice for 15-20 minutes QID × 24 hours
• Elevate extremity

Patient Counseling Points

Key Information for Patients

• Blood counts: Will be monitored regularly; report fever, unusual bleeding/bruising
• Infection risk: Avoid sick contacts, practice good hygiene
• Nausea: Take anti-nausea medications as prescribed
• Contraception: Carboplatin may harm an unborn baby. Avoid pregnancy, and ask your team how long to use birth control after treatment
• Breastfeeding: Stop breastfeeding during treatment
• Fertility: May affect ability to have children

When to Contact Healthcare Provider

• Fever ≥100.4°F (38°C)
• Signs of infection
• Unusual bleeding or bruising
• Severe nausea/vomiting not controlled by medication
• Numbness/tingling in hands or feet
• Hearing changes or ringing in ears
• Allergic reaction symptoms
• Severe fatigue or weakness

Lifestyle Modifications

• Stay hydrated (unless fluid restricted)
• Eat small, frequent meals
• Avoid raw foods during neutropenia
• Use soft toothbrush
• Avoid NSAIDs without approval

Cost & Financial Assistance

Cost Information

• Generic available: Yes - significantly reduces cost
• Average wholesale price: $50-200 per cycle (generic)
• Insurance coverage: Generally covered by Medicare Part B and commercial insurance

Financial Assistance Programs

• Patient assistance programs through manufacturers
• CancerCare Co-Payment Assistance Foundation
• Patient Advocate Foundation
• Good Days (formerly CDF)
• Hospital financial assistance programs

Cost-Saving Tips

• Use generic version when available
• Check if eligible for 340B pricing
• Compare prices between treatment facilities
• Ask about financial counseling services

Frequently Asked Questions

What does AUC mean for carboplatin?

AUC stands for area under the curve. It describes how much of the drug your body is exposed to over time. Your oncologist picks a target AUC, such as AUC 5, and then uses your kidney function to work out the dose in milligrams that should reach that target.

Why is carboplatin dosed by kidney function and not by weight?

Your kidneys clear most of the carboplatin from your body. If they clear it slowly, the same dose gives you more exposure and more side effects. Basing the dose on kidney function helps people with different kidney function reach a similar exposure.

When are blood counts lowest after carboplatin?

When carboplatin is used alone, the lowest point usually comes around day 21. Most people have recovered by about day 28. Combination treatment can change the timing, so ask your team which days to watch closely.

Can I become allergic to carboplatin after many cycles?

Yes. Reactions are rare in the first few cycles and become more likely with repeated treatment. Reports describe a peak around the seventh cycle or later, often in people treated again for a return of ovarian cancer. Earlier cycles without a problem do not rule out a reaction later.

What should I do if I feel strange during a carboplatin infusion?

Tell your nurse at once. Flushing, itching, rash, back pain, chest tightness, trouble breathing, or feeling faint can be early signs of a reaction. Staff can stop the infusion and treat you right away. A reaction can also begin after you leave, so get emergency help if you have trouble breathing or swelling of the face or throat.

Can I have carboplatin again after a reaction?

Sometimes. It depends on how severe the reaction was and on your other treatment options. Some cancer centers use desensitization, which gives the drug very slowly in small steps with close monitoring. Others may change to a different drug. Do not assume either way until you have talked with your oncologist.

Will I lose my hair on carboplatin?

Carboplatin alone rarely causes hair loss. In the label, 2% of people had hair loss on carboplatin alone. It was much more common, at 49%, when carboplatin was combined with cyclophosphamide. Your risk depends on the other drugs in your plan.

Related Information

References

1. Carboplatin [package insert]. Various manufacturers. Revised 2025.
2. National Comprehensive Cancer Network. NCCN Drugs & Biologics Compendium. 2026.
3. Calvert AH, et al. Carboplatin dosage: prospective evaluation of a simple formula based on renal function. J Clin Oncol. 1989;7(11):1748-56.
4. Micromedex Solutions. Carboplatin monograph. Truven Health Analytics. 2026.
5. Clinical Pharmacology. Carboplatin drug monograph. Elsevier. 2026.
6. Lexicomp Online. Carboplatin. Hudson, OH: Wolters Kluwer. 2026.

Sources

• Carboplatin injection prescribing information, DailyMed
• Pandey A, et al. Carboplatin hypersensitivity in relapsed ovarian carcinoma: A therapeutic challenge. Indian J Med Paediatr Oncol. 2014
• Neutropenia (Low Neutrophil Count), American Cancer Society