Vemurafenib (Oral)

Vemurafenib is a type of treatment for skin cancer that works to interfere with the growth of, and the spread of, cancer cells throughout the body.

Overview

Vemurafenib is a medication which is prescribed for the treatment of certain kinds of skin cancers which cannot otherwise be managed by surgery, or which may have spread to other areas within the body. It belongs to a class of medications which are known as kinase inhibitors, and it works by obstructing the actions of harmful proteins that attempt to signal cancer cells into multiplication.

In some cases, it will at least delay the spread of cancer cells, and at other times it will stop that spread altogether. Vemurafenib is a tablet which can be orally ingested and is normally taken twice a day, in conjunction with a normal meal during the morning and evening time, ideally about 12 hours apart.

Approval from the Food and Drug Administration (FDA) for Vemurafenib was granted in August of 2011 for the treatment of melanoma in its later stages. This made Vemurafenib the very first drug to gain regulatory approval for this kind of treatment. In the following year, Health Canada also bestowed approval for Vemurafenib for the treatment of skin cancers. In that same year, the European Commission approved the drug as a treatment for adult patients with metastatic melanoma, which represents the most highly aggressive type of skin cancers.

Vemurafenib cannot be prescribed for all types of skin cancers, since it is known that it only works on melanoma patients who have contracted the specific type of cancer which has the V600E BRAF mutation. Approximately 60% of all instances of melanoma do have this mutation and are therefore treatable with Vemurafenib, but those cancers without these specific mutations are unaffected by usage of the drug. In those cases, for some unknown reason, the drug actually seems to stimulate tumor growth and accelerates melanoma metastasis. For this reason, precise testing must be done on patients with melanoma before prescribing Vemurafenib for treatment.

Conditions Treated

  • Skin cancer

Type of Medicine

  • Kinase Inhibitor

Side Effects

Side effects which appear as a result of taking Vemurafenib should be closely monitored and recorded in between doctor visits. When you do see your doctor, make sure to fully report all these side effects, so that your doctor can make an evaluation of whether or not any of them are dangerous, or might be indicators of a potential problem.

Some side effects which suddenly appear and do not go away after a few days, or become more severe as days go by, should be carefully noted. Examples of these are hair loss, dry or itchy skin, tiredness or fatigue, pain in the joints, muscles, arms, legs, or back, headaches, diarrhea or constipation, or a noticeable difference in your sense of taste.

Another class of side effects are considered to be more serious, and should not wait until the next doctor visit, but should be reported immediately. Examples of these side effects are blurred vision, extreme sensitivity to light, swelling or inflammation around the eyes, a yellowish tint around the eyes or on the skin in general, a stabbing pain in the upper right portion of the abdomen, nausea and vomiting, persistent lack of appetite, unexplained bruises or bleeding, extreme fatigue, new warts or skin sores that bleed or do not heal, or any kind of change in the size or color of a mole, which you had prior to taking Vemurafenib.

One more group of side effects which is considered even more serious calls for a specific response from you to immediately halt ingestion of Vemurafenib and to contact your physician immediately. If your doctor is unavailable for an appointment, you should then seek counseling at an emergency health care clinic. If you do have to go to an emergency care unit, make sure you take your list of prescriptions, and vitamins or supplements along with all their dosages, so that medical personnel are fully aware of your medical condition, and the treatment program you are currently on.

Pay close attention for any of the following symptoms which might appear as a result of taking Vemurafenib: difficulty breathing or swallowing of food or beverages, fainting spells, rashes or redness all over your body, skin which blisters or peels in certain areas, hives, extremely high temperature, and heartbeat that is either rapid, irregular, or pounding for fairly long periods of time.

Dosage

For best results, Vemurafenib should be taken at the same times each day, and all directions printed on the label should be adhered to carefully. If there are any instructions on the printed label which are not clear, or which the patient does not understand, a family doctor should be asked to thoroughly explain what is intended by the directions.

Patients taking it should never take more or less of Vemurafenib than has been prescribed explicitly by your doctor, and its usage should never be discontinued without first consulting the family physician. It's possible that your doctor may recommend that you stop taking Vemurafenib for a period of time, in order to monitor results and to see how your body tolerates any side effects.

For this reason, it's important that you continually update your physician about how you feel while taking the drug, and about any side effects you feel may have been caused by Vemurafenib. Whenever you are prescribed to take this drug, you will be issued a Medication Guide which should explain thoroughly how it is to be taken, and what to look for in the way of side effects. When you actually ingest the Vemurafenib tablets, be sure to swallow them whole, rather than attempting to chew them or crush them up prior to ingestion.

Interactions

Make sure you have a thorough discussion with your doctor about any prescription medications you are currently taking, as well as any non-prescription medications, herbal products, nutritional supplements, and even vitamins. If you are planning to start taking any of these medications or any of the non-prescription supplements, be sure that your doctor is aware of that as well.

Your doctor should also know about any antifungals you are taking, any medications for human immunodeficiency virus (HIV), or acquired immunodeficiency syndrome (AIDS), as well as any medications for irregular heartbeat or seizures.

Any medications that you are currently taking should be written down on a list for your doctor, along with the dosages that you are taking. This is also a good list to keep handy in the event that you need to make an unplanned visit to a healthcare clinic or emergency center for some kind of treatment. If you are taking several medications currently, you may not remember them all, or you may not remember what the dosages are for each of those medications. That makes it very important to have such a list handy in an emergency situation, so you can prevent any harmful interactions with the drugs you're currently taking, and those which might be administered at the emergency center.

It's important that you don't have any immunizations which include live vaccines when you are on a treatment program including Vemurafenib, and you should also not have any such immunizations for a period of six months beyond your treatment program. For immunizations which do not include live vaccines, it is possible that they are at least somewhat less effective than they should be, and provide less protection than anticipated.

You should also avoid extensive contact with people who have orally ingested vaccines, for instance, the rotavirus vaccine which is typically administered to infants. The reason for this is that the virus remains in the baby's urine for as long as two weeks, and if you should come in contact with that in any way, it has the potential for making you seriously ill.

The following drugs have been known to interact negatively with Vemurafenib:

  • Coumadin, Jantoven (blood thinners);
  • Cyclosporine, sirolimus, or tacrolimus
  • digoxin
  • theophylline
  • ADHD medications
  • antidepressants like amitriptyline
  • antifungal medications
  • cancer medicines like doxorubicin
  • ergotamine or dihydroergotamine
  • cough medicines like dextromethorphan
  • pain medications such as codeine
  • heart or blood pressure medications like betaxolol, captopril, or carvedilol
  • heart rhythm medications
  • HIV/AIDS medications like atazanavir
  • medicine to treat psychiatric disorders
  • seizure medications like carbamazepine

Warnings

There are a number of precautions you should take if your doctor prescribes Vemurafenib as a program of treatment for you. Most of these precautions have to do with fully informing your physician about your medical history, and about your current medical status.

You can begin by telling your doctor if you know that you are allergic to Vemurafenib or any of the ingredients which you know are included in the tablets. These ingredients will be listed in the Medication Guide, so that you know for sure what's included in the medication itself.

Let your doctor know if you've ever had any kind of skin cancer or any heart problems which may have led to an irregular heartbeat or fainting spells. Also inform your doctor if you've ever had a low level of potassium, magnesium, or calcium in your system at any time in the past, which was identified as a medical condition.

If you are pregnant or you are hoping to become pregnant, or if you're expecting to become the father of a child, this should also be discussed with your physician. If you do begin a treatment program which includes Vemurafenib, you should not consider becoming pregnant for the duration of the prescription.

If necessary, it is advisable to use birth control pills to ensure that no possibility of pregnancy occurs while you are taking Vemurafenib. The reason for all these precautions for both you and your partner is that it's very possible Vemurafenib could harm a developing fetus, so the drug should never be ingested during pregnancy. Along those same lines, you should also not breast-feed while you are taking Vemurafenib.

If you expect to have any type of surgery performed during the period you are taking Vemurafenib, make sure your surgical doctor is aware of this. This alert extends to dental surgery as well as to surgery on any other part of the body. For the entire time frame that you are going through a prescription of Vemurafenib, you should do your best to avoid prolonged exposure to sunlight.

If it's necessary for you to be outside for hours at a time, be sure to wear sunscreen on exposed skin, wear protective clothing whenever possible, don sunglasses to protect your eyes, and use lip balm to shield your lips from harmful rays. The reason for these precautions is that Vemurafenib can cause your skin to be much more sensitive to sunlight than it would ordinarily be, thus magnifying the effects of any direct sunlight which does reach your skin surfaces.

This means you should avoid changing diapers for at least two weeks after babies have been vaccinated in this way, or you can wear disposable gloves to ensure that you don't come into any direct contact with the urine. Also, make sure not to come into contact with people who have had a typhoid vaccination within the last month or so, or who have had an oral treatment for polio.

It is possible that new primary malignancies may appear when taking Vemurafenib, although the incidence of this is primarily associated with individuals who are 65 years old or above who have had a prior history of skin cancer, or who have been subjected to prolonged sun exposure in their past. If you should notice any new skin lesions appearing between doctor visits, make sure to point these out to your physician at the very next visit.

Some serious types of hypersensitivity reactions such as anaphylaxis can occur during treatment, or in cases where Vemurafenib is being reintroduced with a particular patient after a prior discontinuance. Some other kinds of hypersensitivity reactions which may occur are erythema and hypotension.

Dermatologic reactions including Stevens-Johnson Syndrome, as well as toxic epidermal necrolysis, can occur as well, and if any of these types of conditions appear, Vemurafenib should be discontinued as a treatment immediately.

Some kinds of liver injury or damage are possible with usage, including functional hepatic impairment, and if any abnormalities such as this appear, it should be handled either with temporary interruption, complete discontinuation of treatment, or possibly by dosage reduction, if in the physician's judgment, that is more warranted.

Heightened photosensitivity is another possible reaction when using Vemurafenib, although this can be managed fairly effectively by avoiding prolonged exposure to sunlight, and wearing protective clothing at all times.

Various levels of renal failure are also possible when taking Vemurafenib, and in at least one-quarter of studied cases, patients who were prescribed the drug had elevated creatinine levels. While elevated creatinine levels do not necessarily lead to kidney damage, they are at least worthy of additional monitoring and periodic laboratory testing, to ensure that levels do not continue to escalate and cause damage. Anyone with pre-existing kidney issues, therefore, would probably not be a good candidate for treatment which included Vemurafenib, unless dosages were maintained at a very low level.

Storage

Vemurafenib is a medication which should always be kept in the container it came in, tightly sealed, and in a location where children cannot possibly access it. It can be stored safely at room temperature, but it must be kept away from excess heat and any kind of humid conditions. This means that storing it on the bathroom shelf with other medications or with other toiletries is not at all a good idea, since bathrooms are typically subject to high humidity and high temperature, at least temporarily.

Although you should not discontinue taking Vemurafenib without consulting your family doctor, if it is his recommendation that the prescription is discontinued, then it should be disposed of in a safe manner. By a ‘safe manner', it is meant that disposal should occur in a place where pets, children, and other adults cannot possibly access or consume the unused medication. It is not recommended to flush unused portions of your prescription down the toilet.

If possible, you should see if there is some kind of a ‘take-back' program available in your community, so that you can simply drop off the unused part of your medication, and have it safely handled by professionals. If there is no such program in your community or anywhere nearby, you should check with the FDA website for Safe Disposal of Medicines, to find out how and where to get rid of unused medications.

When storing Vemurafenib, the medication should always be kept out of sight of small children, who are notoriously curious. This means that it's not a good idea to put your medications in a generic weekly pill reminder container. Very few of these containers are constructed to be child resistant, and in fact, they usually encourage exploration by curious children.

Make sure that during storage, your medication bottles have the safe-lock tops fully emplaced, preferably in a location that is well above the accessible height of any children in the home. If you happen to forget about how many dosages you've had in a given day, and you suspect that you may have overdosed, you should immediately call your local Poison Control Center and follow their instructions.

Summary

You should never allow anyone else to take your medication, because there's no way of knowing what other medications that person might be taking, and the potential exists for dangerous drug interactions. Make sure to keep all doctor appointments as scheduled, especially if you are experiencing side effects which are new since your last visit.

If you doctor schedules laboratory tests for you, these should also definitely be kept as scheduled, because the likelihood is that some of those tests relate to how your body is tolerating Vemurafenib, and what your overall response is to the medication. Observable reactions like skin rashes, or inflammation at various sites around the body can be checked right in the doctor's office, during your regularly scheduled visits.

Vemurafenib can be very effective in the treatment of skin cancers, when surgery is not an option, or in cases where cancer cells have spread throughout the body. It must be taken with caution, however, and only under the direct supervision of a physician, with whom you have regularly scheduled visits, so your body's reactions to the drug can be closely monitored.

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Last Reviewed:
December 23, 2017
Last Updated:
April 05, 2018
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