Side Effects From Steroids & Premedications

A lot of chemotherapy appointments start with drugs that are not chemotherapy. The most common is a steroid, usually dexamethasone. It often comes paired with an antihistamine. These are premedications. They prevent or reduce nausea and vomiting caused by chemotherapy. They also prevent allergic reactions caused by some chemotherapy drugs, such as docetaxel and paclitaxel.

They are described as helpers. So people are often not warned that they can be strongly felt in their own right. Knowing what is expected takes a lot of the alarm out of it.

For nausea, dexamethasone is taken about 30 minutes before chemotherapy. It may then be continued every 12 hours after chemotherapy, for a period your team specifies. For preventing allergic reactions, it is taken before specific drugs like docetaxel or paclitaxel. Take it with food and a glass of water or milk. Maybe you miss a dose, or vomit within one hour of taking dexamethasone. Take it as soon as you can.

Take it exactly as prescribed. Do not skip doses. Do not take more than directed.

Trouble falling asleep on treatment days is a listed effect of dexamethasone given as a premedication. Insomnia and restlessness are also listed among dexamethasone's side effects in general. So lying wide awake on the night of chemo is a known drug effect. It is not a personal failing. Sleep is expected to return to normal when you stop taking dexamethasone.

Discuss sleep concerns with your doctor. Do not change the steroid dose yourself. Our page on sleep problems during cancer treatment covers what actually helps.

Depression and anxiety are both listed side effects of dexamethasone. The general instruction is to tell your doctor if any of these symptoms are severe or do not go away.

For dexamethasone used as a premedication, mood changes carry a stronger instruction. See your doctor as soon as possible, during office hours, if you have mood changes. That is not an emergency-room instruction. But it is not a wait-until-next-cycle one either.

This is the effect people are least often warned about. The consumer drug information says: "If you have diabetes, dexamethasone may increase your blood sugar level. If you monitor your blood sugar (glucose) at home, test your blood or urine more frequently than usual. Call your doctor if your blood sugar is high or if sugar is present in your urine; your dose of diabetes medication and your diet may need to be changed."

Dexamethasone raises the risk of stomach irritation. That is why you take it with food or milk. Heartburn is listed for premedication use. So is an increased risk of stomach problems, including bleeding ulcers. Acetaminophen can be used for minor pain. Ask your doctor about the timing of any antacid.

People on steroids widely describe appetite and weight changes. But the consumer drug information we used here does not list increased appetite or weight gain among dexamethasone's side effects. On the urgent side, it does list swelling of the face, lower legs, or ankles. If your appetite or weight changes noticeably, raise it with your team. Do not assume it is unavoidable.

Steroids lower the body's immune response. So you are more likely to get sick. Report any injuries or signs of infection that occur during treatment. Those signs are fever, sore throat, pain during urination, and muscle aches. Avoid contact with anyone who has chicken pox or measles.

Do not stop taking dexamethasone without talking to your doctor. Stopping suddenly can cause loss of appetite, upset stomach, vomiting, drowsiness, confusion, headache, fever, joint and muscle pain, peeling skin, and weight loss. If the steroid is to be stopped, your doctor will likely decrease the dose gradually.

Diphenhydramine is often given before chemotherapy to help prevent allergic reactions. Common effects are drowsiness, dizziness, dry mouth, dry nose and throat, and muscle weakness. The instruction is plain: "Do not drive a car or operate machinery until you know how this medication affects you." Alcohol adds to the drowsiness, so avoid alcoholic drinks while taking it. Arrange a ride home from infusion days. In older adults, diphenhydramine should not be used, except to manage serious allergic reactions. Vision problems should prompt an immediate call to your doctor. So should difficult or painful urination.

• Call 911 or go to an emergency department if breathing gets difficult, your throat or tongue swells, you come out in hives, or you feel faint during or after an infusion. Those are signs of a severe allergic reaction, which the premedications are given to prevent but cannot rule out.
• Get help immediately, at any hour, if your temperature reaches 100.4°F (38°C) or higher while you are on chemotherapy. Steroids blunt the immune response, and CDC treats a fever during chemotherapy as a medical emergency. Use the after-hours number, or go to an emergency department.
• Call your care team the same day if you get a skin rash, a swollen face, lower legs or ankles, vision problems, muscle weakness, black or tarry stool, or a cold or infection that drags on. These are the effects MedlinePlus says to report immediately.
• Call your care team the same day if your blood sugar reading is high, or sugar shows up in your urine, or your mood changes. Mood changes carry an office-hours instruction, not a wait-and-see one.
• Call your care team within a day or two if any of these are severe or will not go away: upset stomach, vomiting, headache, dizziness, insomnia, restlessness, depression, anxiety, acne, easy bruising, or menstrual changes.

If your own team has given you a different rule about when to call between visits or after hours, follow their rule.

Steroid Insomnia, Anxiety, and Mood Changes, Sleep Problems During Cancer Treatment, Side Effects of Cancer Treatment, and Fever and Infection Concerns During Cancer Treatment.

• MedlinePlus, U.S. National Library of Medicine, Dexamethasone
• MedlinePlus, U.S. National Library of Medicine, Diphenhydramine
• BC Cancer, For the Patient: Dexamethasone (for premedication)
• Centers for Disease Control and Prevention, Fever and Cancer Treatment