(fos' am pren a veer)
[Posted 3/1/2012]ISSUE:FDA notified healthcare professionals of updates to the prescribing information concerning interactions between protease inhibitors and certain statin drugs. Protease inhibitors and statins taken together may raise the blood levels of statins and increase the risk for muscle injury (myopathy). The most serious form of myopathy, called rhabdomyolysis, can damage the kidneys and lead to kidney failure, which can be fatal.
BACKGROUND:Statins are a class of prescription drugs used together with diet and exercise to reduce blood levels of low-density lipoprotein (LDL) cholesterol (''bad cholesterol''). HIV protease inhibitors are a class of prescription anti-viral drugs used to treat HIV. HCV protease inhibitors are a class of prescription anti-viral drugs used to treat hepatitis C infection.
RECOMMENDATION:Healthcare professionals should follow the recommendations in the prescribing information (drug labels) when prescribing HIV or HCV protease inhibitors with statins. See the FDA Drug Safety Communication for additional information, including a data summary. For more information visit the FDA website at: Web Siteand Web Site.
WHY is this medicine prescribed?
Fosamprenavir is used with other medications to treat human immunodeficiency virus (HIV) infection in patients with or without acquired immunodeficiency syndrome (AIDS). Fosamprenavir is in a class of medications called protease inhibitors. It works by slowing the spread of HIV in the body. Fosamprenavir does not cure HIV infection and may not prevent you from developing HIV-related illnesses. Fosamprenavir does not prevent you from spreading HIV to other people.
HOW should this medicine be used?
Fosamprenavir comes as a tablet to take by mouth. It is usually taken with or without food once or twice a day. To help you remember to take fosamprenavir, take it around the same time(s) every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take fosamprenavir exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Fosamprenavir controls HIV infection but does not cure it. Continue to take fosamprenavir even if you feel well. Do not stop taking fosamprenavir without talking to your doctor. If you miss doses or stop taking fosamprenavir, your condition may become more difficult to treat.
Are there OTHER USES for this medicine?
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
What SPECIAL PRECAUTIONS should I follow?
Before taking fosamprenavir,
- tell your doctor and pharmacist if you are allergic to fosamprenavir, amprenavir (Agenerase), sulfa medications, or any other medications.
- tell your doctor if you are taking cisapride (Propulsid); ergot medications such as dihydroergotamine (D.H.E. 45, Migranal), ergoloid mesylates (Hydergine, Gerimal), ergonovine (Ergotrate), ergotamine (Bellamine, Cafergot, Migergot), methylergonovine (Methergine), and methysergide (Sansert); midazolam (Versed); pimozide (Orap); or triazolam (Halcion). Your doctor will probably tell you not to take fosamprenavir if you are taking one or more of these medications.
- do not take flecainide (Tambocor) or propafenone (Rhythmol) if you are taking fosamprenavir and ritonavir (Norvir) together.
- tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, and nutritional supplements you are taking. Be sure to mention any of the following: anticoagulants ('blood thinners') such as warfarin (Coumadin); antidepressants such as amitriptyline (Elavil), amoxapine (Asendin), clomipramine (Anafranil), desipramine (Norpramin), doxepin (Adapin, Sinequan), fluoxetine (Prozac), fluvoxamine (Luvox), imipramine (Tofranil), nefazodone (Serzone), nortriptyline (Aventyl, Pamelor), paroxetine (Paxil), protriptyline (Vivactil), trazodone, and trimipramine (Surmontil); benzodiazepines such as alprazolam (Xanax), clorazepate (ClorazeCaps, Tranxene), diazepam (Valium), and flurazepam (Dalmane); buspirone (BuSpar); calcium channel blockers such as amlodipine (Lotrel, Norvasc), diltiazem (Cardizem, Dilacor, Tizac), felodipine (Lexxel, Plendil), isradipine (DynaCirc), nicardipine (Cardene), nifedipine (Adalat, Nifedical, Procardia), nimodipine (Nimotop), nisoldipine (Sular), and verapamil (Calan, Covera, Isoptin, Verelan); chlorpheniramine (antihistamine in cough and cold medicines); cholesterol-lowering medications (statins) such as atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Altocor, Mevacor), and simvastatin (Zocor); clarithromycin (Biaxin); danazol (Danocrine); dexamethasone (Decadron); erythromycin (E.E.S., E-mycin, Erythrocin); fluconazole (Diflucan); histamine H2-receptor blockers such as cimetidine (Tagamet), famotidine (Pepcid), nizatidine (Axid), and ranitidine (Zantac); isoniazid (INH, Nydrazid); itraconazole (Sporanox); ketoconazole (Nizoral); medications for irregular heartbeat such as amiodarone (Cordarone, Pacerone), bepridil (Vascor), flecainide (Tambocor), propafenone (Rhythmol), and quinidine (Quinidex); medications for seizures such as carbamazepine (Tegretol), ethosuximide (Zarontin), phenobarbital (Luminal, Solfoton), and phenytoin (Dilantin); medications that suppress the immune system such as cyclosporine (Neoral, Sandimmune), sirolimus (Rapamune), or tacrolimus (Prograf); methadone (Dolophine, Methadose); metronidazole (Flagyl); other medications to treat HIV including amprenavir (Agenerase), delavirdine (Rescriptor), efavirenz (Sustiva), indinavir (Crixivan), lopinavir (Kaletra), nelfinavir (Viracept), nevirapine (Viramune), saquinavir (Fortovase, Invirase), and ritonavir (Norvir); proton-pump inhibitors such as esomeprazole (Nexium), lansoprazole (Prevacid), omeprazole (Prilosec), pantoprazole (Protonix), and rabeprazole (AcipHex); quinine; rifabutin (Mycobutin); rifampin (Rifadin, Rimactane); tamoxifen (Nolvadex); terfenadine (Allegra); troleandomycin (TAO); vincristine (Vincasar); and zafirlukast (Accolate). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
- tell your doctor if you are taking medications for erectile dysfunction such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil (Levitra). You should know that fosamprenavir may increase the chance that you will experience serious side effects from these medications. If you are taking any of these medications and you experience dizziness, fainting, upset stomach, changes in vision, or a painful erection that lasts for several hours, call your doctor right away.
- tell your doctor what herbal products you are taking, especially St. John's wort.
- tell your doctor if you have or have ever had diabetes, hemophilia (a disease in which the blood does not clot normally), high cholesterol or triglycerides, kidney or liver disease, or if you smoke or if you drink or have ever drunk large amounts of alcohol.
- tell your doctor if you are pregnant or plan to become pregnant. If you become pregnant while taking fosamprenavir, call your doctor. You should not breast-feed if you are infected with HIV or are taking fosamprenavir.
- if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking fosamprenavir.
- you should know that fosamprenavir may decrease the effectiveness of oral contraceptives (birth control pills). Talk to your doctor about other ways to prevent pregnancy while you are taking this medication.
- you should know that your body fat may increase or move to different areas of your body such as your breasts and upper back.
What SPECIAL DIETARY instructions should I follow?
Talk to your doctor about drinking grapefruit juice while taking this medicine.
What should I do IF I FORGET to take a dose?
If you miss a dose and remember after less than 4 hours have passed, take the missed dose immediately. However, if you remember after more than 4 hours have passed, call your doctor to find out if you should skip the missed dose. Do not take a double dose to make up for a missed dose.
What SIDE EFFECTS can this medicine cause?
Fosamprenavir may cause hyperglycemia (high blood sugar). Call your doctor immediately if you have any of the following symptoms of hyperglycemia:
- extreme thirst
- frequent urination
- extreme hunger
- blurred vision
If high blood sugar is not treated, a serious, life-threatening condition called diabetic ketoacidosis could develop. Call your doctor immediately if you have any of the these symptoms:
- dry mouth
- nausea and vomiting
- shortness of breath
- breath that smells fruity
- decreased consciousness
Fosamprenavir may cause other side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- extreme tiredness
Some side effects can be serious. The following symptoms are uncommon, but if you experience any of them, call your doctor immediately:
- skin rash
- difficulty breathing or swallowing
- sore throat, fever, chills, cough, and other signs of infection
- back or side pain
- blood in urine
- pain when urinating
Fosamprenavir may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
Laboratory animals who were given amprenavir (Agenerase), a medication similar to fosamprenavir, developed tumors. It is not known if fosamprenavir increases the risk of tumors in humans. Talk to your doctor about the risks of taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at Web Site] or by phone [1-800-332-1088].
What should I know about STORAGE and DISPOSAL of this medication?
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
What should I do in case of OVERDOSE?
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
What OTHER INFORMATION should I know?
Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests before and during your treatment to be sure it is safe for you to take fosamprenavir and to check your body's response to fosamprenavir.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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