An HIV Information Site & HIV Educational Resource Site (HIS & HERS)

rifabutin - Mycobutin

General Information Rifabutin (Mycobutin) is an antibiotic that is used to treat and prevent certain infections.
Specifics Rifabutin is a well-respected and very effective antibiotic.  It has a long track record of effectiveness and safety.

Rifabutin works by inhibiting the production of protein in mycobacteria, the family of germs that tuberculosis is in.  Rifabutin is used for a variety of purposes including but not limited to the following:

1.  To treat some forms of tuberculosis (TB) with several other medications
2.  To treat a serious infection called DMAC ("disseminated Mycobacterium avium complex") which is found in the blood, bone marrow, liver, and/or other organs.  Here again rifabutin is almost always combined with other medications.
3.  To prevent DMAC.  This is probably its most frequent use.

Dosing Rifabutin may be given by capsule once or twice a day.

If taken to prevent DMAC, the usual dose is 150-300 once a day.

If you are taking protease inhibitors especially ritonavir (Norvir) or lopinavir/ritonavir (Kaletra), you should only take 150 mg of rifabutin once a day or every other day as advised by your healthcare provider.

Your dose may be reduced if you have weak kidneys.

This refers to your willingness, ability, and actual performance in taking your medications.

For further information and tips on adherence, go to the Adherence section of this site.

It is very important to take every dose that is prescribed unless instructed by your healthcare provider.

Do not adjust the dose or frequency of rifabutin without speaking to your healthcare provider first.

If you miss doses, the infection that is being treated may not get better or sometimes the infection can even get much worse by the germ developing resistance to rifabutin or you may get DMAC if you are taking rifabutin for prevention.

It is strongly recommended that you consider using weekly pill boxes and arrange all of your doses a week in advance.  Buy a small pill box so that you can carry a dose or two of your medicines with you in case you are away from home.

Possible Side Effects
The package insert for most drugs including rifabutin is often overwhelming and scary with perhaps an overemphasis on side effects.  We have summarized the important and more common problems here.

Most people take rifabutin without any or very many side effects.  

Many side effects get better with time.

The most frequent side effect of rifabutin is orange, red, or yellow discoloration of the urine, tears and sweats.  If you wear contact lenses, this drug may stain these lenses.

Other possible side effects include stomach upset, nausea, liver problems, fever, allergic rashes, and problems with your blood cells.

An infrequent but serious side effect of rifabutin is an inflammatory condition of the eyes called uveitis.  Uveitis may result in damage to the eyes if it is not diagnosed and treated quickly.  The symptoms of uveitis are eye pain, eye redness, and loss of vision.  If you experience these symptoms while on rifabutin, report them to your healthcare provider as soon as possible.

Allergic rashes can be very minor to very serious (rarely,) but all rashes should be reported.  If you have rash that steadily gets worse or you have a rash and fever, you need to inform your healthcare provider immediately.

This refers to the way that rifabutin affects other medications and how other medications might affect rifabutin.

There are several other drugs which should be used cautiously with the knowledge of their possible interactions with rifabutin:

itraconazole (Sporanox)
delavirdine (Rescriptor)
protease inhibitors including indinvavir (Crixivan,) lopinavir/ritonavir (Kaletra,) nelfinavir (Viracept,) saquinavir (Invirase or Fortovase,) atazanavir (Reyataz,) fosamprenavir (Lexiva,) etc.
birth control pills (contraceptives): women should change to or supplement with nonhormonal methods of birth control
anticoagulant treatment with warfarin (Coumadin)

Many other drugs may be affected to lesser degrees including the following:

anticonvulsants (eg, phenytoin), antiarrhythmics (eg, disopyramide, mexiletine, quinidine, tocainide), oral anticoagulants, antifungals (eg, fluconazole, itraconazole, ketoconazole), barbiturates, beta-blockers, calcium channel blockers (eg, diltiazem, nifedipine, verapamil), chloramphenicol, clarithromycin, corticosteroids, cyclosporine, cardiac glycoside preparations, clofibrate, dapsone, diazepam, doxycycline, fluoroquinolones (eg ciprofloxacin, levofloxacin), haloperidol, oral hypoglycemic agents (sulfonylureas), levothyroxine, methadone, narcotic analgesics, nortriptyline, progestins, quinine, tacrolimus, theophylline tricyclic antidepressants (eg, amitriptyline, nortriptyline), and zidovudine.

Make sure that your healthcare provider is aware of all the medications you are taking so that important and possibly dangerous interactions are not overlooked.

Report to you healthcare provider or go to an Emergency Room if you have severe side effects, increasing side effects, shortness of breath, fever, eye pain or redness, loss of vision, jaundice (eyes and skin turn yellow,) nausea and vomiting (so that you cannot hold down your food and liquids) or rash.
You can download this handout in PDF format by clicking HERE.