Foscavir

Generic name: Foscarnet
Drug class: Miscellaneous antivirals

Usage of Foscavir

Foscavir is an antiviral medicine that prevents certain viruses from multiplying in your body.

Foscavir is used to treat cytomegalovirus (CMV) retinitis in people with AIDS.

Foscavir is also used to treat herpes simplex virus (HSV) in people with a weak immune system. This medicine is usually given for HSV after other antiviral medications have been tried without successful treatment.

Foscavir is not a cure for CMV or HSV, and your virus may progress during or after treatment.

Foscavir may also be used for purposes not listed in this medication guide.

Foscavir side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Foscavir may cause serious side effects. Call your doctor at once if you have:

pain or burning when you urinate;

a seizure (convulsions);

headache with chest pain and severe dizziness, fainting, fast or pounding heartbeats;

low white blood cell counts--fever, swollen gums, painful mouth sores, pain when swallowing, skin sores, cold or flu symptoms, cough, trouble breathing;

low red blood cells (anemia)--pale skin, feeling light-headed or short of breath, rapid heart rate, trouble concentrating;

low calcium--numbness or tingly feeling around your mouth, fast or slow heart rate, muscle tightness or contraction, overactive reflexes;

low potassium--constipation, numbness or tingling, tiredness, muscle weakness, slow heart rate, fainting; or

kidney problems--little or no urinating; painful or difficult urination; swelling in your feet or ankles; feeling tired or short of breath.

Some of Foscavir leaves the body in urine, which can cause irritation when you urinate. You may also develop sores or ulcers around your urethra (the opening where urine passes out of your bladder). Drink plenty of fluids and take care to keep your genital area clean while receiving this medicine.

Common side effects of Foscavir may include:

fever, flu-like symptoms;

nausea, vomiting, diarrhea;

chest pain, back pain; or

headache.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Before taking Foscavir

You should not use Foscavir if you are allergic to it.

To make sure Foscavir is safe for you, tell your doctor if you have:

kidney disease;

heart disease, heart rhythm disorder;

personal or family history of long QT syndrome;

an electrolyte imbalance (such as low levels of calcium, potassium, or magnesium in your blood);

epilepsy or other seizure disorder; or

if you are on a low salt diet.

It is not known whether Foscavir will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It is not known whether foscarnet passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using this medicine.

Relate drugs

How to use Foscavir

Follow all directions on your prescription label. Your doctor may occasionally change your dose. Do not use this medicine in larger or smaller amounts or for longer than recommended.

Foscavir is injected into a vein through an IV using an infusion pump. The medicine enters the body through a catheter placed into the vein. A healthcare provider will show you how to use an infusion pump. Do not self-inject this medicine if you do not understand how to give the injection and properly dispose of used needles, IV tubing, and other items used to inject the medicine.

You may also be given IV fluids to keep you from getting dehydrated.

You may need to mix Foscavir with a liquid (diluent) before using it. If you are using the injections at home, be sure you understand how to properly mix and store the medicine. Do not give this medicine with other medicines in the same IV line.

Foscavir should be clear and colorless. Gently shake the medicine if appears to have separated. Do not use the medicine if it has changed colors or has particles in it. Call your pharmacist for new medicine.

The medicine must be injected slowly and can take up to 2 hours to complete. Injecting Foscavir too fast can cause dangerous or unwanted side effects.

Foscavir is usually given for 2 to 3 weeks. Follow your doctor's dosing instructions very carefully.

While using Foscavir, your kidney function and electrolytes (potassium, sodium, magnesium, phosphorus) will need to be tested often, and you may also need regular eye exams.

Store Foscavir at room temperature away from very hot or very cold temperature.

Warnings

Foscavir can harm your kidneys. This effect is increased when you also use certain other medicines, including: antivirals, chemotherapy, injected antibiotics, medicine for bowel disorders, medicine to prevent organ transplant rejection, injectable osteoporosis medication, and some pain or arthritis medicines (including aspirin, Tylenol, Advil, and Aleve).

Your kidney function and electrolytes (potassium, sodium, magnesium, phosphorus) will need to be tested often.

Injecting Foscavir too fast can cause dangerous or unwanted side effects.

What other drugs will affect Foscavir

Tell your doctor about all your current medicines and any you start or stop using, especially:

anagrelide, cilostazol, donepezil, fluconazole, methadone, ondansetron;

an antibiotic or antifungal medicine--azithromycin, ciprofloxacin, clarithromycin, erythromycin, fluconazole, levofloxacin, moxifloxacin, pentamidine, telithromycin;

cancer medicine--arsenic trioxide, oxaliplatin, vandetanib;

an antidepressant--citalopram, escitalopram;

anti-malaria medication--Chloroquine, halofantrine;

heart rhythm medicine--amiodarone, disopyramide, dofetilide, dronedarone, flecainide, ibutilide, procainamide, quinidine, sotalol; or

medicine to treat a psyChiatric disorder--chlorpromazine, droperidol, haloperidol, pimozide, thioridazine.

This list is not complete. Other drugs may interact with foscarnet, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Disclaimer

Every effort has been made to ensure that the information provided by Drugslib.com is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Drugslib.com information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Drugslib.com does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Drugslib.com's drug information does not endorse drugs, diagnose patients or recommend therapy. Drugslib.com's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners.

The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Drugslib.com does not assume any responsibility for any aspect of healthcare administered with the aid of information Drugslib.com provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.