Overview
Topotecan belongs to a family of drugs called antineoplastics, which interferes with the proliferation of cancerous cells resulting in destruction. Sometimes, the drug may also kill healthy cells. The drug is only available by doctor’s prescription. It was first approved by the Food Drug Administration in 1990 after the phase 2 clinical trials. The drug gained approval for both ovarian and small-cell lung cancer in 1996. It is the first orally used topoisomerase one inhibitor.
How Does Topotecan Work?
The drug is a type of topoisomerase inhibitor that blocks the chemical topoisomerase 1. This chemical is important in DNA (deoxyribonucleic acid) replication and transcription. In addition, it alters the chromosome structure by changing the topological state of DNA. They are also capable of relaxing supercoiled DNA and interlocking DNA. Blocking this is extremely important to prevent the proliferation of cancerous cells.
Cancerous cells affect the immune system and attack the healthy cells of the body. This, in turn, causes optimistic infections to occur. Diagnosing cancer early is a boon to the patient, as the treatments are very effective and bring positive outcomes. Topotecan is used explicitly in the treatment of small lung cell cancer.
Uses:
The drug is usually injected intravenously in patients with metastatic cancer. Metastasis refers to the spread of cancerous cells from a particular site to other body parts. The drug is combined with another cancerous drug called Cisplatin to treat cervical cancer. The drug is effective in patients with small-cell lung cancer.
Dosage:
The drug is available in both oral and intravenous formulations. Depending on the requirements and the severity of lung cancer, the doctor will decide on the route of drug administration. The drug is available in various doses and is prescribed according to the patient's weight.
Warnings:
Before starting Topotecan it is mandatory to watch out for the following to avoid any health issues.
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Allergies - Inform the doctor if there had been any unusual allergic reaction to any drug in the past. Also, allergies regarding food, dyes, and preservatives must be conveyed.
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Pediatric - There are no appropriate studies that prove the efficacy of drugs in children. Hence the safety of the drug is unknown in pediatric patients.
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Geriatric - Appropriate studies are to be demonstrated in elderly individuals. Most elderly individuals may suffer from age-related kidney problems, so caution should be taken before injecting the drug.
For Patients
What Is Small Cell Lung Cancer?
A disease in which the cancerous cells are found in the lung tissue is called small-cell lung cancer. It is an aggressive and fast-growing variant of cancer. It may rapidly spread to other parts of the body. It primarily affects the cells and tissues of the lungs. The primary factor causing lung cancer includes smoking.
So chronic smokers are at a higher risk of acquiring the disease. Besides, individuals constantly exposed to asbestos, arsenic, chromium, and nickel also have a higher probability of acquiring the condition. Old age may also be an important risk factor for most cancers. Air pollutants and a family history of cancer are some of the contributing factors.
The signs and symptoms of small-cell lung cancer are mentioned below:
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Loss of appetite.
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Difficulty in swallowing.
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Extreme tiredness.
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Swelling in the face.
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Weight loss.
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Hoarseness of voice.
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Chest discomfort.
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Breathing difficulty.
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Blood in the sputum.
The condition is diagnosed by undergoing a thorough physical examination and blood tests. In addition, the doctor may advise a few imaging tests like chest X-rays, to identify the extent of the tumor and the metastasis. It also gives a clear indication of the damage occurring in the lungs.
Learn More About Topotecan
How Effective Is Topotecan?
The drug has been proven to be highly effective in treating small-cell lung cancer and is useful when used in combination with a few other anti-cancer drugs.
Things to Inform the Doctor Before They Prescribe Topotecan:
Before the doctor prescribes any medication, inform them regarding any previous drug allergies and current medical and drug history. This helps to avoid drug interactions and overdosing. Always carry a copy of the prescription while visiting the doctor, this helps them better evaluate their health status.
Starting Topotecan:
Before starting any drug, it is always essential to understand the risks of the medication over the positive outcomes. The doctor will analyze the patient’s health condition and prescribe medications to treat cancer and prevent a recurrence. Hence, patient cooperation is a crucial factor in the success of the treatment.
How to Take Topotecan?
Topotecan can be either administered intravenously or in the form of oral capsules that have to be taken after food as prescribed by the doctor.
Look Out for Side Effects:
In case of the following side effects, inform the health care professional.
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Bleeding gums.
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Black stools.
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Body aches.
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Pain.
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Chest pain.
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Chills.
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Congestion.
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Cough.
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Sore throat.
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Fever.
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Lower back pain.
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Difficult urination.
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Pale skin.
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Trouble swallowing.
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Fatigue or tiredness.
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Changes in voice.
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Spots in the mouth.
Some of the other less common effects, while consuming Topotecan are,
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Confusion.
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Dizziness.
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Fainting.
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Fast heartbeat.
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Nausea.
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Pain in the abdomen.
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Shallow breathing.
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Stomach pain.
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Vomiting.
Dietary Alterations:
No specific dietary alterations are required in patients consuming Topotecan. Unless suggested by the doctor, a regular diet would suffice. Maintaining a healthy and balanced diet is crucial while consuming medications. It helps to absorb the medications and keeps the body nourished. Poor nourishment could have adverse effects on the overall health of an individual.
What Should Be Done When a Dose Is Missed?
In case of missing an oral dose of Topotecan, take the medication at the earliest possible. If it is already time for the next dose, then it is better to avoid the missed dose and continue with a regular routine. Do not skip doses frequently as it could delay improving the disease or condition.
In case of missing any chemotherapeutic session, it is important to inform the doctor and reschedule the appointment. Missing a dose could affect the prognosis of the condition. Patients undergoing treatment regularly, have proven better improvement with time. Timely treatment can always help with better prognosis and outcomes.
What Should Be Done to Treat Topotecan Overdose?
Oral capsules of Topotecan should only be used in limited dosages as suggested by the doctor. Overdosing the drug could affect normal and healthy cells, resulting in side effects. In case of overdosing, immediately contact the health care professional. It is rare to overdose on intravenously administered Topotecan as it is done in hospitals under the doctor's supervision and the dosage is continuously monitored. In case of overdosing, the injection is carefully removed and the drug administration is stopped immediately.
How to Store Topotecan?
The drug is available in the form of intravenous injections and oral capsules. Hence, it has to be stored in a cold and dry place. Do not keep it reachable to children or pets as it could be dangerous.
How to Handle Topotecan?
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Always use gloves while consuming oral capsules to avoid contamination.
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Keep the bottle tightly sealed after taking the required medication.
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Do not keep it near children or pets.
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Always check the label of the box for expiry. Do not consume any drug post-expiration.
How to Dispose of Topotecan?
It is always safer to contact the local take-back programs to discard the drugs and avoid any biohazards safely. Do not flush the drug in the toilet or the dustbin. It is better to keep them separate and dispose of them via medical waste management.
Avoid Self-Medication:
Never consume any drug more than the required dosage, as it causes ill effects. Self-medication is extremely harmful and hence has to be avoided in any circumstance. Always take a doctor’s consultation before taking medication.
Staying On Topotecan
Tips to Stay On Track:
The best tip to stay on track for any medication is to set a reminder on the phone and to take the drug every day at the same time until it becomes a habit. Missing a dose could be detrimental in affecting the overall health of an individual.
For Doctors
Indication:
The drug has been successfully used to treat ovarian and small-cell lung cancer. It inhibits the proliferation of DNA strands and breaks them down into single units which inhibits the growth of cancerous cells.
Pharmacology:
Mechanism of Action: The drug is a derivative of Camptothecin and a topoisomerase inhibitor, that prevents the re-ligating cleaved DNA strand and subsequently causes DNA damage. Inactivation of topoisomerase could cause apoptosis and cell death. The drug binds to topoisomerase 1 DNA complex and breaks them into single strands. This interferes with the replicating fork, leading to induction and replication arrest, breaking the lethal double-stranded DNA.
Taxonomy:
Kingdom - Organic compounds.
Subkingdom - Organic oxygen compounds.
Superclass - Organic heterocyclic compounds.
Class - Indoles and derivatives.
Subclass - Indolines.
Direct parent - Campththecins.
Molecular formula - C23H23N3O5.
Pharmacodynamics: Topotecan is an anticancer agent and novel semisynthetic derivative of the anticancer agent Camptothecin. The lactone structure helps maintain the equilibrium with the inactive ring of hydroxy acid. This is an essential activity and predominates at physiological pH (power of hydrogen).
Ingredients:
Active Ingredients:
The drug consists of an active substance called Topotecan, a Camptothecin derivative, that is produced from the tree Camptotheca acuminata. The nuclear enzyme helps relieve the torsional strain in DNA and helps to break them into single-stranded DNA.
Inactive Ingredients:
Some of the inactive ingredients in Topotecan are mentioned below:
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Mannitol.
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Tartaric acid.
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Hydrochloric acid.
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Sodium hydroxide.
Absorption:
The bioavailability of the drug in oral form is roughly about 35 percent. Lower bioavailability is caused due to the hydrolysis action of Topotecan lactone, present in the gut. It yields substantial amounts of the open-ring form, which could cause poor absorption.
Distribution:
The drug has a wide distribution in the peripheral space. It makes up a total volume of about 75 liters at the steady state of the drug.
Metabolism:
The drug undergoes reversible pH-dependent hydrolysis. The lactone form of the drug is pharmacologically active. At acidic pH, the drug is exclusively available. In the ring-opened form, hydroxy-acid predominates the condition.
Elimination:
The mean elimination of the drug is roughly three hours. The renal clearance accounts for about 40 percent of the dose and has a large interindividual availability. The drug is eliminated via the kidneys after it undergoes filtration.
Toxicity:
Drug toxicity may result in the following medical conditions:
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Bone marrow suppression.
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Anemia.
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Thrombocytopenia.
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Pancytopenia.
The dose-limiting toxicity is observed in many individuals, approximately 50 to 75 percent in clinical trials.
Contraindications:
The drug is an absolute contraindication in patients with a history of hypersensitivity or allergic reactions.
Drug Interactions:
While undergoing Topotecan injection, it is better to avoid the following drugs, as they may cause drug interaction:
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Measles live vaccine.
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Mumps live vaccine.
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Rotavirus live vaccine.
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Zoster vaccine.
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Varicella virus vaccine.
Other Specifications:
Topotecan in Pregnant Women:
The drug’s efficiency in pregnant women is not known completely, hence it is not prescribed in pregnant women as it could cross the placenta and affect the unborn child, resulting in birth deformities.
Topotecan in Lactating Women:
Studies are being conducted to understand the drug's efficacy in pregnant women. Most studies are yet to prove the exact side effects and potential risks the drug could cause on breastfeeding women. Hence it is not currently prescribed for lactating women.
Topotecan in Pediatric Patients:
The drug is not usually advised in pediatric patients. There are very few supporting studies regarding drug usage in children.
Topotecan in Geriatric Patients:
The drug could be harsh on elderly individuals, especially those with kidney impairment. Hence it is important to carefully administer Topotecan injections in elderly individuals after outweighing the potential risks and complications.
Topotecan in Renal Impairment Patients:
In patients with kidney impairment, the drug could aggravate the impairment, hence it should be carefully administered and followed up regularly to monitor the prognosis of the lung cancer.
Topotecan in Hepatic Impairment Patients:
Although there have not been any relative complications in patients with hepatic impairment, it has to be used with caution to avoid any complications.
