Hycamtin (Topotecan)
Topoisomerase I Inhibitor for Relapsed Small Cell Lung Cancer
Quick Facts About Hycamtin
Key Takeaways
- Hycamtin (topotecan) is a chemotherapy drug used to treat small cell lung cancer that has returned after previous treatment.
- Capsules must be swallowed whole — never chewed, crushed, or opened — and are taken once daily for 5 consecutive days per treatment cycle.
- The most significant side effect is bone marrow suppression, leading to low blood counts that increase the risk of serious infections and bleeding.
- Regular blood tests are essential before and during each treatment cycle to ensure blood cell counts are at safe levels.
- Topotecan must not be used during pregnancy or breastfeeding, and both men and women must use effective contraception during and after treatment.
What Is Hycamtin and What Is It Used For?
Hycamtin contains the active substance topotecan, which belongs to a class of anticancer drugs known as topoisomerase I inhibitors. These medicines work by interfering with the activity of topoisomerase I, an enzyme that plays a critical role in DNA replication and repair within cells. When topotecan binds to the topoisomerase I-DNA complex, it stabilises the temporary breaks that the enzyme creates in the DNA strand. This prevents the DNA from being properly repaired, leading to permanent double-strand DNA breaks when the cell attempts to divide. These irreparable breaks trigger apoptosis (programmed cell death) preferentially in rapidly dividing cancer cells.
The oral capsule formulation of Hycamtin is specifically approved for the treatment of relapsed small cell lung cancer (SCLC). Small cell lung cancer is an aggressive form of lung cancer that tends to grow and spread quickly. While SCLC often responds well to initial chemotherapy, it frequently recurs. Hycamtin provides a second-line treatment option when the original chemotherapy regimen is no longer considered appropriate for re-treatment. Your oncologist will evaluate whether Hycamtin capsules are a better option compared to continuing with or repeating the chemotherapy regimen you initially received.
The intravenous formulation of topotecan has additional approved indications. It may be used in combination with cisplatin for the treatment of recurrent carcinoma of the cervix after radiotherapy, and as monotherapy for metastatic ovarian cancer when first-line or subsequent therapy has failed. However, these indications apply only to the intravenous form administered in a hospital setting. The oral capsule form discussed in this article is authorised specifically for relapsed small cell lung cancer.
Topotecan was originally derived from camptothecin, a natural compound isolated from the bark of the Chinese tree Camptotheca acuminata. The semi-synthetic modification improved its water solubility and clinical utility. Hycamtin was first approved by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA), and it remains an important treatment option in oncology practice worldwide, particularly for patients with limited second-line treatment options for SCLC.
What Should You Know Before Taking Hycamtin?
Hycamtin is a potent chemotherapy agent, and several important factors must be assessed before treatment begins. Your oncologist will carry out a thorough medical evaluation, including blood tests and an assessment of your overall health, to determine whether Hycamtin is safe and appropriate for you. It is essential that you provide your doctor with a complete medical history and inform them of all medications you are currently taking.
Contraindications
You must not take Hycamtin in the following situations:
- Allergy to topotecan: If you are allergic to topotecan hydrochloride or any of the other ingredients in the capsule (including gelatin, titanium dioxide, glyceryl monostearate, or hydrogenated vegetable oil), you must not use this medicine. Signs of an allergic reaction may include skin rash, itching, swelling, difficulty breathing, or feeling faint.
- Breastfeeding: You must not breastfeed while taking Hycamtin. Topotecan may pass into breast milk and could harm a nursing infant. Breastfeeding must not be resumed until your doctor confirms it is safe to do so.
- Severely low blood counts: Treatment must not begin if your blood cell counts have fallen below acceptable levels. Your doctor will inform you based on the results of your most recent blood test. Specifically, neutrophil counts must be at least 1.5 × 10⁹/L and platelet counts at least 100 × 10⁹/L before the oral capsule form can be started.
Warnings and Precautions
Before starting treatment with Hycamtin, inform your doctor about the following:
- Kidney problems: Topotecan is partially excreted through the kidneys, and impaired kidney function can lead to higher drug levels in the body. If you have mild to moderate kidney impairment, your dose may need to be reduced. Hycamtin oral capsules are generally not recommended for patients with severe renal impairment (creatinine clearance below 20 ml/min), as there is insufficient clinical data in this population.
- Liver problems: While topotecan is not extensively metabolised by the liver, hepatic impairment may affect the overall handling of the drug. Your doctor may need to adjust your treatment plan accordingly.
- Bone marrow function: Hycamtin causes predictable and significant myelosuppression (suppression of bone marrow activity). This is the most clinically important side effect and can lead to dangerously low levels of white blood cells (neutropenia), red blood cells (anaemia), and platelets (thrombocytopenia). Your blood counts will be monitored regularly, and treatment may be delayed or dose-reduced if counts fall too low.
- Current infections: Because Hycamtin suppresses the immune system, any existing infection should ideally be treated and resolved before starting chemotherapy. Tell your doctor if you have any signs of infection such as fever, cough, painful urination, or skin wounds that are slow to heal.
Hycamtin can cause severe bone marrow suppression leading to life-threatening infections, bleeding, or anaemia. Complete blood counts must be performed before every treatment cycle. Contact your doctor immediately if you develop a fever above 38°C (100.4°F), unexplained bruising or bleeding, or signs of infection during treatment.
Pregnancy and Breastfeeding
Hycamtin can cause harm to an unborn child. Based on its mechanism of action (interfering with DNA replication), topotecan has the potential to cause birth defects and foetal death. Animal studies have confirmed embryotoxic and teratogenic effects. For these reasons:
- Women of childbearing potential must use effective contraception during treatment with Hycamtin and for at least 6 months after the last dose. If you become pregnant during treatment, inform your doctor immediately. A pregnancy test should be performed before initiating therapy.
- Male patients are advised to use effective contraception and must not father a child during treatment and for at least 3 months after the last dose. Men who wish to have children in the future should discuss fertility preservation options (such as sperm banking) with their doctor before starting treatment.
- Breastfeeding is strictly prohibited during Hycamtin treatment. It is not known precisely how much topotecan passes into human breast milk, but given the drug's mechanism of action, any exposure could be harmful to the infant. Do not resume breastfeeding until your doctor confirms it is safe.
Driving and Operating Machinery
Hycamtin may cause fatigue, weakness, and dizziness as side effects. If you experience any of these symptoms, you must not drive a car or operate heavy machinery until the symptoms resolve. Chemotherapy-related fatigue can be persistent and may affect your ability to perform tasks requiring concentration and coordination. Discuss with your oncologist how treatment may affect your daily activities.
How Does Hycamtin Interact with Other Drugs?
Drug interactions can alter the way Hycamtin works or increase the risk of side effects. Before starting treatment, inform your oncologist about all medicines you are taking, have recently taken, or might take, including prescription drugs, over-the-counter medicines, vitamins, and herbal supplements. It is also important to tell your doctor if you begin any new medication during your Hycamtin treatment.
Significant Interactions
| Interacting Drug | Effect | Clinical Significance |
|---|---|---|
| Cyclosporine A | Increases topotecan exposure by inhibiting P-glycoprotein and BCRP efflux transporters | Higher than normal risk of side effects; close monitoring required if co-administered |
| P-glycoprotein inhibitors (e.g. elacridar, ritonavir, saquinavir) | May increase systemic exposure to topotecan by reducing drug efflux | Potential for increased toxicity; use with caution and monitor blood counts more frequently |
| BCRP inhibitors | May increase oral bioavailability and reduce renal clearance of topotecan | Use caution; dose adjustments may be necessary |
| G-CSF (Filgrastim) | Can prolong neutropenia duration if given concurrently during chemotherapy | If G-CSF is used, it should not be started until at least 24 hours after the last dose of Hycamtin in each cycle |
| Other myelosuppressive agents | Additive bone marrow suppression | Enhanced myelotoxicity; careful monitoring of blood counts required |
Additional Considerations
Topotecan is a substrate for the P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) efflux transporters. Drugs that inhibit these transporters can increase the amount of topotecan in the body, potentially leading to increased toxicity. Conversely, strong inducers of these transporters could theoretically reduce topotecan exposure, although this interaction has not been extensively studied clinically.
The Hycamtin capsule formulation contains small amounts of ethanol (alcohol). While the quantity is very small and unlikely to cause noticeable effects in most patients, individuals who are particularly sensitive to alcohol or who are taking medications that interact with alcohol should be aware of this component.
There is no clinically significant interaction between topotecan and the cytochrome P450 enzyme system, as topotecan is not primarily metabolised by CYP enzymes. This means that many common drug interactions mediated through CYP3A4 or other CYP pathways do not apply to Hycamtin, which simplifies its use in patients taking multiple medications.
What Is the Correct Dosage of Hycamtin?
Hycamtin must always be taken exactly as prescribed by your oncologist. The dosage is individually calculated and should never be adjusted without medical supervision. Your doctor will determine the correct dose based on your body surface area (measured in square metres, m²), the results of your blood tests, and your overall health status.
Adults
Oral Capsules (Relapsed SCLC)
The recommended dose is 2.3 mg/m²/day taken orally once daily for 5 consecutive days, repeated every 21 days (3 weeks). The prescribed number of capsules (combining 0.25 mg and 1 mg capsules as needed) should be swallowed whole, once a day. The total number of capsules will be rounded to the nearest practical dose using the available capsule strengths.
Intravenous Infusion (Hospital Setting)
For the IV formulation (used for SCLC, ovarian cancer, or cervical cancer), the typical dose is 1.5 mg/m²/day administered as a 30-minute intravenous infusion daily for 5 consecutive days, repeated every 21 days. IV dosing is determined and administered by the hospital oncology team.
Dose Adjustments
Your oncologist may reduce the dose of Hycamtin in the following circumstances:
- Low blood counts: If your neutrophil count falls below 1.0 × 10⁹/L for more than 7 days, or if you develop febrile neutropenia (fever with low white blood cell count), or if your platelet count falls below 25 × 10⁹/L, the dose may be reduced by 0.4 mg/m²/day for subsequent cycles.
- Kidney impairment: Patients with mild to moderate renal impairment (creatinine clearance 20–39 ml/min) should receive a reduced dose. Your doctor will calculate the appropriate adjustment based on your kidney function test results.
- Severe side effects: If you experience severe diarrhoea (grade 3 or 4) or other significant toxicities, your dose may be reduced for future treatment cycles.
How to Take the Capsules
Hycamtin capsules require careful handling due to the cytotoxic nature of the active ingredient:
- Swallow the capsules whole with water. Do not chew, crush, or open them.
- The capsules can be taken with or without food.
- The capsules are supplied in child-resistant blister packaging. To remove a capsule: tear along the perforated line to separate one blister pocket, peel off the outer covering starting from the coloured tab, and gently push the capsule through the foil.
- If a capsule is damaged or leaks, wash your hands immediately and thoroughly with soap and water. If the contents contact your eyes, flush immediately with a gentle stream of water for at least 15 minutes and seek medical attention.
Missed Dose
If you forget to take a dose of Hycamtin, do not take a double dose to make up for the missed one. Simply take your next dose at the usual scheduled time and continue with your normal dosing schedule. Inform your oncologist if you have missed a dose, as this may affect the overall efficacy of the treatment cycle.
Overdose
If you take more Hycamtin capsules than prescribed, or if a child accidentally ingests the medicine, contact your doctor or go to the nearest emergency department immediately. Overdose with topotecan is likely to cause severe myelosuppression (bone marrow suppression), and supportive care including blood count monitoring, blood transfusions, and infection prophylaxis may be necessary. There is no specific antidote for topotecan overdose.
What Are the Side Effects of Hycamtin?
As with all medicines, Hycamtin can cause side effects, although not everyone will experience them. Because topotecan is a cytotoxic chemotherapy agent, it affects rapidly dividing cells throughout the body, not only cancer cells. This means that side effects are expected and often predictable. Your oncology team will monitor you closely and can provide treatments to manage many of these effects.
Contact your doctor or go to hospital immediately if you experience: fever above 38°C (especially with low blood counts), severe diarrhoea (more than 3 episodes per day), signs of infection (sore throat, burning sensation when urinating, sudden deterioration of general condition), unusual bruising or bleeding, difficulty breathing, or severe abdominal pain.
Very Common
- Neutropenia — severely reduced white blood cells, increasing infection risk; may be life-threatening
- Anaemia — low red blood cell count causing fatigue, weakness, and pallor; blood transfusions may be needed
- Thrombocytopenia — low platelet count leading to easy bruising and increased bleeding risk
- Infections — increased susceptibility due to weakened immune system, including serious and potentially fatal infections
- Nausea and vomiting — common with chemotherapy; anti-emetic medicines are usually prescribed
- Diarrhoea — can be severe; contact your doctor if more than 3 episodes per day
- Alopecia (hair loss) — usually temporary; hair typically regrows after treatment ends
- Fatigue and weakness — significant tiredness that may affect daily activities
- Loss of appetite (anorexia) and weight loss
Common
- Allergic or hypersensitivity reactions including skin rash
- Oral mucositis — inflammation and sores in the mouth, on the tongue, or gums
- Fever (pyrexia)
- Abdominal pain, constipation, and indigestion
- General feeling of being unwell (malaise)
- Itching (pruritus)
Uncommon
- Jaundice — yellowing of the skin and whites of the eyes, indicating liver involvement
Rare
- Interstitial lung disease (ILD) — inflammation of lung tissue causing difficulty breathing, cough, and fever; highest risk in patients with pre-existing lung conditions, prior lung radiation, or history of lung-damaging medications
- Severe anaphylactic reactions
- Angioedema — swelling beneath the skin due to fluid accumulation
- Urticaria (hives) — itchy, raised skin rash
Not Known
- Gastrointestinal perforation — severe stomach pain, nausea, vomiting blood, black or bloody stools (a medical emergency)
- Mucosal inflammation — sores in the mouth, difficulty swallowing, abdominal pain, nausea, vomiting, diarrhoea, and bloody stools
- Colitis — severe abdominal pain, fever, and in rare cases bloody diarrhoea (inflammation of the intestinal wall)
Managing Side Effects
Many side effects of Hycamtin can be managed with supportive care. Your oncology team will work with you to minimise discomfort and reduce the risk of serious complications:
- Infections: You may be prescribed prophylactic antibiotics or antifungal medicines during periods of lowest blood counts (nadir). Practice good hand hygiene, avoid contact with people who are ill, and report any signs of infection to your doctor immediately.
- Nausea and vomiting: Anti-emetic (anti-sickness) medicines are typically prescribed alongside chemotherapy. Let your doctor know if your current anti-emetic regimen is not adequately controlling symptoms.
- Anaemia: If your haemoglobin drops significantly, you may require blood transfusions. Report symptoms such as extreme tiredness, shortness of breath on exertion, or dizziness.
- Bleeding risk: With low platelet counts, take precautions to avoid cuts and bruising. Use a soft toothbrush, avoid contact sports, and inform your doctor about any unusual bleeding.
- Hair loss: This is usually temporary and hair typically regrows after treatment finishes, although it may initially have a different texture or colour.
It is important to report suspected side effects after a medicine has been approved. This allows ongoing monitoring of the benefit-risk balance. Healthcare professionals and patients are encouraged to report any suspected adverse reactions to their national medicines regulatory authority (e.g., FDA MedWatch in the US, Yellow Card Scheme in the UK, EMA EudraVigilance in the EU).
How Should You Store Hycamtin?
Proper storage of Hycamtin is essential to ensure the medicine remains effective and safe to use. Because topotecan is a cytotoxic agent, special care must be taken to prevent accidental exposure, particularly to children.
- Temperature: Store in a refrigerator at 2–8°C (36–46°F). Do not allow the capsules to freeze.
- Light protection: Keep the blister packs inside the outer cardboard carton to protect them from light, as topotecan can degrade when exposed to light.
- Child safety: The capsules are supplied in child-resistant blister packaging. Nevertheless, keep the medicine out of the sight and reach of children at all times.
- Expiry date: Do not use after the expiry date printed on the carton and blister pack. The expiry date refers to the last day of that month.
- Disposal: Do not dispose of medicines via household waste or down the drain. Ask your pharmacist how to properly dispose of medicines that are no longer needed. Cytotoxic medicines require special disposal procedures to protect the environment.
What Does Hycamtin Contain?
Understanding the composition of your medicine can help identify potential allergens and provide useful information for your healthcare team.
| Component | 0.25 mg Capsule | 1 mg Capsule |
|---|---|---|
| Active substance | Topotecan 0.25 mg (as hydrochloride) | Topotecan 1 mg (as hydrochloride) |
| Capsule contents | Hydrogenated vegetable oil, glyceryl monostearate | Hydrogenated vegetable oil, glyceryl monostearate |
| Capsule shell | Gelatin, titanium dioxide (E171) | Gelatin, titanium dioxide (E171), red iron oxide (E172) |
| Printing ink | Black iron oxide (E172), shellac, ethanol (anhydrous), propylene glycol, isopropyl alcohol, butanol, concentrated ammonia solution, potassium hydroxide | |
| Appearance | Opaque, white to off-white, printed “Hycamtin” and “0.25 mg” | Pink, printed “Hycamtin” and “1 mg” |
| Pack size | 10 capsules per pack | 10 capsules per pack |
The capsule printing ink contains small amounts of ethanol (alcohol). The quantity is extremely small and unlikely to produce any perceptible effect. The inactive ingredients serve various pharmaceutical functions: hydrogenated vegetable oil and glyceryl monostearate are used as excipients within the capsule filling, while gelatin forms the capsule shell. Titanium dioxide provides the white colouring for the 0.25 mg capsule, and red iron oxide gives the 1 mg capsule its distinctive pink colour.
The marketing authorisation holder for Hycamtin is Sandoz Pharmaceuticals d.d. (Ljubljana, Slovenia). The capsules are manufactured by Salutas Pharma GmbH (Barleben, Germany). Generic versions of topotecan are also available from other manufacturers including Topotecan Accord and Topotecan Ebewe.
Frequently Asked Questions About Hycamtin
Hycamtin oral capsules are approved for the treatment of relapsed small cell lung cancer (SCLC) when re-treatment with the original chemotherapy regimen is not considered appropriate. The intravenous form of topotecan may also be used for recurrent ovarian cancer and cervical cancer (in combination with cisplatin), but these indications apply only to the hospital-administered IV formulation. Your oncologist will determine whether Hycamtin is the most suitable treatment option based on your specific cancer type, stage, and previous treatment history.
Each treatment cycle with Hycamtin oral capsules lasts 21 days (3 weeks). You take the capsules once daily for 5 consecutive days (days 1 to 5), followed by a 16-day rest period before the next cycle begins. The rest period allows your bone marrow and blood counts to recover. The number of cycles you receive depends on how well the cancer responds to treatment and how well you tolerate the side effects. Your oncologist will assess your progress through blood tests and imaging studies at regular intervals throughout your course of therapy.
Unlike many other medicines, topotecan is not primarily metabolised by cytochrome P450 enzymes (including CYP3A4), which is the pathway through which grapefruit juice typically causes drug interactions. Therefore, grapefruit is unlikely to significantly affect topotecan levels. However, it is always advisable to discuss your diet with your oncology team, as general nutritional guidance during chemotherapy is important for maintaining your strength and supporting your immune system during treatment.
If you vomit shortly after taking your Hycamtin capsule, do not take a replacement dose. Simply continue with your next scheduled dose the following day. Inform your oncologist, as they may wish to adjust your anti-emetic (anti-sickness) medication for future doses. Persistent vomiting may affect the amount of drug absorbed, so it is important to report this to your treatment team. They can advise on the best course of action for your individual situation.
Hair loss (alopecia) is a very common side effect of Hycamtin, occurring in more than 1 in 10 patients. The good news is that chemotherapy-related hair loss is almost always temporary. Hair typically begins to regrow within a few weeks to months after treatment ends. When hair grows back, it may initially be a slightly different colour or texture than before, but this usually normalises over time. Speak to your care team about coping strategies, including scalp cooling therapy (if available at your centre), wigs, head coverings, and support groups.
All information is based on international medical guidelines and peer-reviewed sources: the European Medicines Agency (EMA) Summary of Product Characteristics for Hycamtin, US Food and Drug Administration (FDA) prescribing information, ESMO Clinical Practice Guidelines for small cell lung cancer (2024), NCCN Guidelines for Small Cell Lung Cancer, and WHO Model List of Essential Medicines. All medical claims are supported by Level 1A evidence based on systematic reviews of randomised controlled trials or authoritative regulatory documents.
References
- European Medicines Agency (EMA). Hycamtin — Summary of Product Characteristics. Last updated 2024. Available at: ema.europa.eu/en/medicines/human/EPAR/hycamtin
- US Food and Drug Administration (FDA). Hycamtin (topotecan hydrochloride) Prescribing Information. Reference ID: 4867632.
- Eckardt JR, von Pawel J, Pujol JL, et al. Phase III study of oral compared with intravenous topotecan as second-line therapy in small-cell lung cancer. Journal of Clinical Oncology. 2007;25(15):2086–2092. doi:10.1200/JCO.2006.08.3998
- von Pawel J, Schiller JH, Shepherd FA, et al. Topotecan versus cyclophosphamide, doxorubicin, and vincristine for the treatment of recurrent small-cell lung cancer. Journal of Clinical Oncology. 1999;17(2):658–667.
- ESMO Clinical Practice Guidelines. Small Cell Lung Cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Annals of Oncology. 2024.
- National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology: Small Cell Lung Cancer. Version 2.2024.
- World Health Organization (WHO). WHO Model List of Essential Medicines — 23rd List (2023). Geneva: WHO.
- O’Brien MER, Ciuleanu TE, Tsekov H, et al. Phase III trial comparing supportive care alone with supportive care with oral topotecan in patients with relapsed small-cell lung cancer. Journal of Clinical Oncology. 2006;24(34):5441–5447.
Medical Editorial Team
This article has been written and medically reviewed by the iMedic Medical Editorial Team, comprising board-certified specialist physicians in oncology, clinical pharmacology, and internal medicine. Our team follows international clinical guidelines including ESMO, NCCN, and WHO recommendations.
All content undergoes a rigorous multi-step review process including medical accuracy verification, adherence to current guidelines, and readability assessment. Content is updated whenever new guidelines or significant evidence becomes available.
We use the GRADE evidence framework and cite only peer-reviewed sources, regulatory documents, and international clinical guidelines. Evidence Level 1A represents the highest quality of evidence based on systematic reviews of randomised controlled trials.
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