Gemcitabine is a nucleoside analog and a chemotherapeutic agent. It was originally investigated for its antiviral effects, but it is now used as an anticancer therapy for various cancers. Gemcitabine is a cytidine analog with two fluorine atoms replacing the hydroxyl on the ribose. As a prodrug, gemcitabine is transformed into its active metabolites that work by replacing the building blocks of nucleic acids during DNA elongation, arresting tumor growth, and promoting apoptosis of malignant cells.
The structure, metabolism, and mechanism of action of gemcitabine are similar to cytarabine, but gemcitabine has a wider spectrum of antitumor activity.
Gemcitabine is a chemotherapy medication that treats breast cancer, lung cancer, pancreatic cancer and ovarian cancer. A healthcare provider will give you this injection via infusion into a vein at a hospital or clinic.
Gemcitabine is available as an intravenous injection. It is approved by the FDA to treat advanced ovarian cancer in combination with carboplatin, metastatic breast cancer in combination with paclitaxel, non-small cell lung cancer in combination with cisplatin, and pancreatic cancer as monotherapy. It is also being investigated in other cancer and tumor types.
Mechanism of action of Gemcitabine
Gemcitabine is a potent and specific deoxycytidine analog. After uptake into malignant cells, gemcitabine is phosphorylated by deoxycytidine kinase to form gemcitabine monophosphate, which is then converted to the active compounds, gemcitabine diphosphate (dFdCDP) and gemcitabine triphosphate (dFdCTP).
These active metabolites are nucleosides that mediate antitumor effects. dFdCTP competes with deoxycytidine triphosphate (dCTP) for incorporation into DNA, thereby competitively inhibiting DNA chain elongation. The non-terminal position of dFdCTP in the DNA chain prevents detection of dFdCTP in the chain and repair by proofreading 3′5′-exonuclease: this process is referred to as “masked DNA chain termination.” Incorporation of dFdCTP into the DNA chain ultimately leads to chain termination, DNA fragmentation, and apoptotic cell death of malignant cells.
Gemcitabine has self-potentiating pharmacological actions that can increase the probability of successful incorporation of gemcitabine triphosphate into the DNA chain: dFdCDP inhibits ribonucleotide reductase, an enzyme responsible for catalyzing the reactions that generate dCTP for DNA synthesis. Since dFdCDP reduces the levels of dCTP, there is less competition for gemcitabine triphosphate for incorporation into DNA. Gemcitabine can also reduce metabolism and elimination of active metabolites from the target ce1l, prolonging high intracellular concentrations of the active metabolites. Such self-potentiating effects are not present with cytarabine.
How to use Gemcitabine
Gemcitabine 1gm Injection is used in combination with carboplatin to treat ovarian cancer (cancer that begins in the female reproductive organs where eggs are formed) that returned at least 6 months after finishing a previous treatment. Gemcitabine is used in combination with cisplatin to treat a type of lung cancer (non-small cell lung cancer; NSCLC) that has spread to other parts of the body and cannot be treated with surgery. Gemcitabine is also used to treat pancreatic cancer that has spread to other parts of the body and has not improved or worsened after treatment with another medication.
BENEFITS OF GEMCITE INJECTION
In Non-small cell lung cancer, Non-small cell lung cancer is one of the major kinds of lung cancer and it affects both smokers as well as non-smokers. Gemcite 1gm Injection helps treat non-small cell lung cancer and may be given alone or in combination with other medicines. It is a potent and very toxic medicine and you should discuss the risks and benefits with your doctor.
In Breast cancer
Gemcitabine 1gm Injection helps to treat breast cancer and it may be used alone or in combination with other medicines or treatment modalities like chemotherapy. It relieves the symptoms of breast cancer such as breast lumps, bloody discharge from nipples, or changes in the shape or texture of the breast.
In Pancreatic cancer
Gemcitabine 1gm Injection will help to control pancreatic cancer and will relieve the symptoms such as lack of appetite or unexplained weight loss. Gemcite 1gm Injection helps to stop the action of those chemicals that aid in pancreatic cancer growth and spread.
In Urinary bladder cancer
Gemcitabine 1gm Injectionis used in combination with other medicines such as cisplatin to treat urinary bladder cancer that has advanced to later stages or even spread to other regions of the body (metastasized). It is a highly effective medicine and also prevents cancer from returning.
In Ovarian cancer
Gemcitabine 1gm Injection is used in combination with other medicines such as cisplatin to treat urinary bladder cancer that has advanced to later stages or even spread to other regions of the body (metastasized). It is a highly effective medicine and also prevents cancer from returning.
What should I tell my care team before I take this medication?
They need to know if you have any of these conditions:
- blood disorders
- kidney disease
- liver disease
- lung or breathing disease, like asthma
- recent or ongoing radiation therapy
- an unusual or allergic reaction to gemcitabine, other chemotherapy, other medicines, foods, dyes, or preservatives
- pregnant or trying to get pregnant
How should I use this medication?
This drug is given as an infusion into a vein. It is administered in a hospital or clinic by a specially trained health care professional.
Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.
Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.
NOTE: This medicine is only for you. Do not share this medicine with others.
What if I miss a dose?
It is important not to miss your dose. Call your doctor or health care professional if you are unable to keep an appointment.
What may interact with this medication?
•medicines to increase blood counts like filgrastim, pegfilgrastim, sargramostim
•some other chemotherapy drugs like cisplatin
Talk to your doctor or health care professional before taking any of these medicines:
This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.
What should I watch for while using this medication?
Visit your doctor for checks on your progress. This drug may make you feel generally unwell. This is not uncommon, as chemotherapy can affect healthy cells as well as cancer cells. Report any side effects. Continue your course of treatment even though you feel ill unless your doctor tells you to stop.
In some cases, you may be given additional medicines to help with side effects. Follow all directions for their use.
Call your doctor or health care professional for advice if you get a fever, chills or sore throat, or other symptoms of a cold or flu. Do not treat yourself. This drug decreases your body’s ability to fight infections. Try to avoid being around people who are sick.
This medicine may increase your risk to bruise or bleed. Call your doctor or health care professional if you notice any unusual bleeding.
Be careful brushing and flossing your teeth or using a toothpick because you may get an infection or bleed more easily. If you have any dental work done, tell your dentist you are receiving this medicine.
Avoid taking products that contain aspirin, acetaminophen, ibuprofen, naproxen, or ketoprofen unless instructed by your doctor. These medicines may hide a fever.
Do not become pregnant while taking this medicine or for 6 months after stopping it. Women should inform their doctor if they wish to become pregnant or think they might be pregnant. Men should not father a child while taking this medicine and for 3 months after stopping it. There is a potential for serious side effects to an unborn child. Talk to your health care professional or pharmacist for more information. Do not breast-feed an infant while taking this medicine or for at least 1 week after stopping it.
Men should inform their doctors if they wish to father a child. This medicine may lower sperm counts. Talk with your doctor or health care professional if you are concerned about your fertility.
What side effects may I notice from receiving this medication?
Side effects that you should report to your doctor or health care professional as soon as possible:
- allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
- breathing problems
- pain, redness, or irritation at site where injected
- signs and symptoms of a dangerous change in heartbeat or heart rhythm like chest pain; dizziness; fast or irregular heartbeat; palpitations; feeling faint or lightheaded, falls; breathing problems
- signs of decreased platelets or bleeding – bruising, pinpoint red spots on the skin, black, tarry stools, blood in the urine
- signs of decreased red blood cells – unusually weak or tired, feeling faint or lightheaded, falls
- signs of infection – fever or chills, cough, sore throat, pain or difficulty passing urine
- signs and symptoms of kidney injury like trouble passing urine or change in the amount of urine
- signs and symptoms of liver injury like dark yellow or brown urine; general ill feeling or flu-like symptoms; light-colored stools; loss of appetite; nausea; right upper belly pain; unusually weak or tired; yellowing of the eyes or skin
- swelling of ankles, feet, hands
Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
- hair loss
- loss of appetite
This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Where should I keep my medication?
This drug is given in a hospital or clinic and will not be stored at home.
NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.
Reference – Gemcitabine injection