Part Nine - Medications Used In Brain Tumor Treatment

73.   After surgery, I was prescribed dexamethasone. My doctor says I may be on this drug several days. What does dexamethasone do? What are the side effects of dexamethasone? 

74.   What are the side effects of anticonvulsant medication?

75.   My pharmacist said that there may be a "drug interaction" between some of my medications. What does this mean?

76.   My primary care doctor prescribed a medication for my sinus infection. Do I have to tell my oncologist about this drug because I'm on chemotherapy?

77.   I've never been depressed before, but since my diagnosis I feel hopeless at times. Will an antidepressant help? Are there side effects that I need to consider if I'm on chemotherapy?

78.    Can I drink alcohol while taking chemotherapy or anti-seizure medication?

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73.   After surgery, I was prescribed dexamethasone. My doctor says I may be on this drug several days. What does dexamethasone do? What are the side effects of dexamethasone? 

Dexamethasone (Decadron) is a corticosteroid, a medication that reduces edema (swelling) around brain tumors by decreasing the tendency of fluid to leak from the blood vessels into the surrounding brain tissue. In addition to its effects in reducing edema, it is often used with chemotherapy to control nausea and vomiting. Dexamethasone is available as an intravenous form or in tablets. 

Most brain tumor patients are given dexamethasone before surgery, and many have noticed improvement in their symptoms within days of beginning treatment with dexamethasone. However, high doses of dexamethasone cannot be continued indefinitely because of the side effects that tend to become more pronounced with a longer duration of therapy.

Because dexamethasone suppresses normal hormone production by the adrenal gland, serious side effects can occur if you suddenly stop taking it. Follow your doctor's instructions exactly when taking dexamethasone or when tapering off of it.

The side effects of dexamethasone vary with the dose and duration of use, and also from patient to patient. Some of the most common side effects include weight gain, heartburn, fluid retention, muscle weakness, increased appetite, osteoporosis, insomnia, depression, nervousness, mania/mood swings, high blood sugar, low potassium, high blood pressure, thinning hair, rash or acne, thin skin, increased risk of infection, and cataracts.

Rapid withdrawal of dexamethasone may cause muscle and joint aches, low blood pressure, loss of appetite, nausea and vomiting, low-grade fever, and headache. Sometimes it is necessary to continue the dose of dexamethasone at a constant level for a longer period of time to allow recovery from steroid withdrawal symptoms. After recovery, your doctor will try to taper the drug at a slower rate.

Dexamethasone also can interact with many drugs, including anticonvulsants such as phenytoin (Dilantin) and phenobarbitol. Dexamethasone may cause stomach upset when given with aspirin or non-steroidal anti-inflammatory drugs such as ibuprofen (Advil).

M.L.'s comment:

When I was taking dexamethasone, the primary side effect that I experienced was weight gain. Just about every one I know that has taken dexamethasone has also experienced weight gain. Most people don't like to gain weight (myself included). To go through this experience is very frustrating; however, I had to just "suck it up" and realize that this was part of being sick. Frankly, I was happy to be alive, but the weight gain still bothered me at times. I think it's OK to be frustrated when the weight gain occurs, just as long as you don't let the frustration consume you. I have seen other patients' attitudes become so negative because of their weight gain. This isn't healthy. Just remember the weight WILL COME OFF! I promise! I gained about 20 pounds or more and eventually it all came off. I really had to work at losing the last 5 pounds, but I did lose it.

74.   What are the side effects of anticonvulsant medication?

There are common, expected side effects of anticonvulsant medication, and rare, life-threatening side effects. Follow your doctor's instructions exactly when taking anticonvulsants. Many of these drugs must be closely monitored with blood tests. Table 6 is a list of common anticonvulsant drugs, their common side effects, and the rare but serious side effects that sometimes occur.

Table 6.  Side Effects of Anticonvulsant Medication

M.L.'s comment:

The side effects of anticonvulsant medication can vary depending on the kind that you're taking. For example, I took phenytoin for about 15 months and the primary side effect that I experience was fatigue. It's my understanding that this is a fairly common side effect to expect, and the extent of the fatigue will vary by individual. My neurologist was able to prescribe another medication called modafinil (Provigil) to assist with the fatigue that I experienced while on phenytoin. My husband called it my "picker upper" because that is exactly what it did. It really was wonderful in giving my body that boost of energy and it kept me from feeling so tired at the end of the day.

I recently changed from phenytoin to a different medication called levetiracetam (Keppra). Levetiracetam is really wonderful because it doesn't cause the same level of fatigue that I was feeling with the phenytoin. In fact, I have been able to stop using the modafinil that I was taking on a daily basis with the phenytoin.

My recommendation is that you talk to your neurologist regularly about how your anticonvulsant medications are making you feel because the side effects can vary with each person. There are other medications that can be prescribed in an effort to assist with your particular needs.

Here's a couple of tips that help me boost my energy when I'm feeling tired:

• When possible try to get some activity incorporated into your schedule. Even a short walk around the block will help get your blood moving and will give your body more energy.

• Take frequent breaks whenever possible. 

• Eat as nutritiously as possible, and don't be afraid to eat. Food gives your body the fuel it needs to keep going.

• If there is a task that doesn't have to be done right away, either don't do it or have someone else do it for you.

• Give yourself permission to stop when you're feeling tired. Take a nap if you need one. Listen to your body and realize that it's OK to allow yourself to take it slow.

75.   My pharmacist said that there may be a "drug interaction" between some of my medications. What does this mean?

Many drugs undergo chemical changes in the body after intravenous or oral administration. When different drugs are used at the same time, the one drug may affect the normal action of the other. Some drugs are chemically processed in the liver, but another drug used simultaneously may affect the normal action of the first drug.  In the case of both chemotherapy drugs and anticonvulsant drugs, the amount of the drug needed to produce the desired effect without toxicity (the therapeutic level) is very important.

Anticonvulsant drug interactions are particularly critical because the patient may have seizures if the therapeutic level drops. Some drugs will raise the anticonvulsant drug level, possibly resulting in a toxic level.  Also, the use of an anticonvulsant drug may render the other drug partially or completely ineffective. Your pharmacist is trained to examine the list of your medications and look for possible drug interactions with your anticonvulsant.

A brief list of common drug interactions with anticonvulsants is given in Table 7.

Table 7            Drug Interactions with Anticonvulsant Medications

Chemotherapy can also interact with other medications. Table 8 lists the most common interactions of chemotherapy drugs.

Table 8 Interactions of Chemotherapy with Other Treatments

76.   My primary care doctor prescribed a medication for my sinus infection. Do I have to tell my oncologist about this drug because I'm on chemotherapy?

Yes. It's a good idea to make sure your doctors know about any changes in your medication, not only because of the possibility of drug interactions, but because of the reason a new drug was prescribed in the first place. Your oncologist will want to know if you have any signs or symptoms of infection while you are taking chemotherapy.  He may delay your next chemotherapy course until you recover from an infection. Your oncologist will also want to closely follow your white blood cell count because an infection can be more serious if the white blood cell count is low.

77.   I've never been depressed before, but since my diagnosis I feel hopeless at times. Will an antidepressant help? Are there side effects that I need to consider if I'm on chemotherapy?

Depression in brain tumor patients can be related to the stress of the diagnosis and treatment, the loss of physical or mental capabilities, and the fear of suffering and death. For patients who have always enjoyed good health, the diagnosis of a brain tumor can be emotionally overwhelming. Almost all patients who are faced with serious illness experience at least temporary grief and anxiety about their condition, but there are some patients who become so distraught that they are unable to make decisions regarding their own care. These patients may benefit from counseling or supportive psychotherapy with a medical professional experienced in dealing with patients with severe illness.

Severely depressed patients and patients with milder forms of depression may benefit from antidepressant medication. Some of the newer antidepressant drugs, known as selective serotonin reuptake inhibitors (SSRIs) include fluoxetine (Prozac), sertraline (Zoloft), paroxetine (Paxil), and citalopram (Celexa). These drugs have fewer side effects than the older tricyclic antidepressants such as amitriptyline (Elavil) and nortriptyline (Pamelor). Moreover, tricyclic antidepressants may increase the risk of seizures in some patients. Another antidepressant, bupropion (Wellbutrin; also known as Zyban when prescribed for smoking cessation) also increases the risk of seizures. 

Patients who are taking procarbazine chemotherapy (one of the components of the popular combination PCV) need to be aware of potential drug interactions with antidepressant medications. Neither the SSRI drugs nor tricyclic antidepressants should be used in patients taking procarbazine.

Some patients resist the idea of taking antidepressant medication because of the large number of other medications they must take. However, studies have shown that cancer patients have an improvement in their overall quality of life when treated for depression. Studies also show that patients treated with antidepressants experience an increase in the number of natural killer cells, the cells that have an important role in the immune system.

78.    Can I drink alcohol while taking chemotherapy or anti-seizure medication?

There are some drugs used in brain tumor therapy that have known toxic reactions with alcohol; these include procarbazine, methotrexate, and thalidomide. Alcohol can interact with many other medications, including anticonvulsants, antidepressants, tranquilizers, sleeping pills, and pain medications. These drugs enhance the effect of alcohol, and therefore driving, even after very small amounts of alcohol, should be strictly forbidden. Patients taking anticonvulsants who also drink may experience wide fluctuations in drug levels, creating a risk of seizures or toxicity. 

Many patients can drink a glass of champagne at a wedding or sip a pina colada on the beach, but regular use of alcohol should be avoided when taking the medications listed above.

M.L.'s comment:

Personally, I would recommend that you NOT drink alcohol while taking chemotherapy. First of all, depending on the type of chemotherapy that you're taking, you'll probably experience fatigue as a side effect. Coupling alcohol with chemotherapy will make you even more tired. If you're like most people, you may experience fatigue with your anti-seizure medication and mixing alcohol with it will make you feel that much worse.