Tacrolimus (FK506)

CAS No: 104987-11-3

Appearance: White crystalline powder

Assay: 99.5% Min

Tacrolimus, previously known as FK506, is the active ingredient in Prograf. Tacrolimus is a macrolide immunosuppressant produced by Streptomyces tsukubaensis . Chemically, tacrolimus is designated as [3 S -[3 R *[ E (1 S *,3 S *,4 S *)],4 S *,5 R *,8 S *,9 E ,12 R *,14 R *,15 S *,16 R *,18 S *,19 S *,26a R *]]-5,6,8,11,12, 13,14,15,16,17,18,19,24,25,26,26a-hexadecahydro-5, 19-dihydroxy-3- [2-(4-hydroxy-3-methoxycyclohexyl) -1-methylethenyl]-14, 16-dimethoxy-4,10,12, 18-tetramethyl-8-(2-propenyl)-15, 19-epoxy-3H-pyrido[2,1- c ][1,4] oxaazacyclotricosine-1,7,20, 21(4H,23H)-tetrone, monohydrate.

Reference:

CDC: Recommendations of the Advisory Committee on Immunization Practices: Use of vaccines and immune globulins in persons with altered immunocompetence. MMWR 1993;42(RR-4):1-18.

IMPORTANT WARNING:
Tacrolimus increases your risk of getting infections. Avoid people with contagious diseases, such as the flu and colds. Keep cuts and scratches clean. Use good personal hygiene, especially for your mouth, teeth, skin, hair, and hands. Tacrolimus also may increase your risk of getting certain types of cancer. Talk to your doctor about this risk.

Why is tacrolimus prescribed?
Tacrolimus is used to prevent rejection of liver transplants. Sometimes it is used to prevent rejection of other types of transplants.

Tacrolimus is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used?
Tacrolimus comes as a capsule to take by mouth and in an injectable form. It usually is taken twice a day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take tacrolimus exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Continue to take tacrolimus even if you feel well. Do not stop taking tacrolimus without talking to your doctor. You will probably take tacrolimus for a long time.

What special precautions should I follow?
Before taking tacrolimus,tell your doctor and pharmacist if you are allergic to tacrolimus or any other drugs.

，Tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially amiloride (Midamor, Moduretic), bromocriptine (Parlodel), carbamazepine (Tegretol), cimetidine (Tagamet), cisapride (Propulsid), clarithromycin (Biaxin), clotrimazole (Mycelex, Lotrimin), cyclosporine (Neoral, Sandimmune), danazol (Danocrine), diltiazem (Cardizem), erythromycin (E-Mycin), fluconazole (Diflucan), ganciclovir (Cytovene), HIV protease inhibitors such as indinavir (Crixivan) and ritonavir (Norvir), itraconazole (Sporanox), ketoconazole (Nizoral), methylprednisolone (Medrol), metoclopramide (Reglan), nefazodone (Serzone), nicardipine (Cardene), nifedipine (Adalat, Procardia), omeprazole (Prilosec), oral contraceptives (birth control pills), phenobarbital, phenytoin (Dilantin), rifabutin (Mycobutin), rifampin (Rifadin, Rimactane), spironolactone (Aldactone), triamterene-containing drugs (Dyazide, Dyrenium, Maxzide), troleandomycin (Tao), verapamil (Calan, Isoptin), and vitamins. Do not take antacids within 2 hours of taking tacrolimus.
，Tell your doctor and pharmacist what herbal products you are taking, especially St. John's wort and products containing St. John's Wort.
，Tell your doctor if you have or have ever had heart or kidney disease or diabetes.
，Tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking tacrolimus, call your doctor.
if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking tacrolimus.

What special dietary instructions should I follow?
Avoid drinking grapefruit juice while taking tacrolimus.

What should I do if I forget a dose?
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What side effects can tacrolimus cause?
Although side effects from tacrolimus are not common, they can occur. Tell your doctor if any of these symptoms are severe or do not go away:

，diarrhea
，upset stomach
，vomiting
，stomach pain
，loss of appetite
，insomnia

If you experience any of the following symptoms, call your doctor immediately:

，fever
，sore throat
，chills
，frequent or painful urination
，decreased urination
，severe or continued headaches
，swelling of the feet, ankles, lower legs, and hands
，weight gain
，tremor
，weakness
，unusual bleeding or bruising
，skin rash
，itching
，hives
，difficulty breathing
，wheezing
，yellowing of the skin or eyes
，seizures

What storage conditions are needed for tacrolimus?
Keep tacrolimus 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.

In case of emergency/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 will order certain lab tests to check your response to tacrolimus and do blood tests to see how your liver and kidneys are working.

Tacrolimus can raise your blood pressure. Talk to your doctor about checking your blood pressure regularly.

Before receiving any vaccinations, tell your doctor that you are taking tacrolimus.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.