Mycobutin


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Related to Mycobutin: Myambutol

rifabutin

Mycobutin

Pharmacologic class: Rifamycin derivative

Therapeutic class: Antimycobacterial

Pregnancy risk category B

Action

Inhibits RNA synthesis by blocking RNA transcription in susceptible organisms (mycobacteria and some gram-positive and gram-negative bacteria)

Availability

Capsules: 150 mg

Indications and dosages

To prevent disseminated Mycobacterium avium intracellulare complex in patients with advanced human immunodeficiency virus (HIV) infection

Adults: 300 mg P.O. daily as a single dose or in two divided doses

Off-label uses

• Tuberculosis

• Prophylaxis and treatment of M. avium intracellulare in children

Contraindications

• Hypersensitivity to drug

• Active tuberculosis

Precautions

Use cautiously in:

• severe hepatic disease

• pregnant or breastfeeding patients.

Administration

• Give in divided doses twice daily with food to reduce GI upset.

Adverse reactions

CNS: headache, asthenia, weakness

CV: pressure sensation in chest

EENT: uveitis; discolored tears, saliva, or sputum

GI: nausea, vomiting, diarrhea, dyspepsia, abdominal pain, eructation, flatulence, discolored feces, anorexia

GU: discolored urine

Hematologic: eosinophilia, neutropenia, leukopenia, thrombocytopenia Musculoskeletal: joint pain, myalgia

Respiratory: dyspnea

Skin: rash, discolored skin or sweat

Other: abnormal taste, fever, flulike symptoms

Interactions

Drug-drug. Clarithromycin, itraconazole, saquinavir: reduced blood levels and efficacy of these drugs

Delavirdine: decreased delavirdine blood level, increased rifabutin blood level

Drugs metabolized by liver (such as zidovudine): altered blood levels of these drugs

Hormonal contraceptives: decreased contraceptive efficacy

Indinavir, nelfinavir, ritonavir: increased rifabutin blood level

Drug-diagnostic tests. Alanine aminotransferase, aspartate aminotransferase, eosinophils: increased levels

Neutrophils, platelets, white blood cells: decreased counts

Drug-food. High-fat foods: delayed drug absorption

Patient monitoring

• Monitor CBC with white cell differential. Watch for signs and symptoms of blood dyscrasias.

• Assess nutritional status.

• Closely monitor vital signs and temperature. Stay alert for dyspnea and flulike symptoms.

Patient teaching

• Advise patient to take twice daily with food (but not high-fat food) if GI upset occurs. To further minimize GI upset, teach him to eat small, frequent servings of healthy food and drink plenty of fluids.

• Instruct patient to take exactly as prescribed, even after symptoms subside.

Tell patient to immediately report easy bruising or bleeding.

• Tell patient drug may turn tears, urine, and other body fluids reddish or brownish orange. Instruct him not to wear contact lenses during therapy because drug may stain them permanently.

• Inform patient that drug occasionally causes eye inflammation. Instruct him to report symptoms promptly.

• Caution patient to avoid driving and other hazardous activities until effects of drug are known.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and foods mentioned above.

rifabutin

(riff-a-byoo-tin) ,

Mycobutin

(trade name)

Classification

Therapeutic: agents atypical mycobacterium
Pregnancy Category: B

Indications

Prevention of disseminated Mycobacterium avium complex (MAC) disease in patients with advanced HIV infection.Treatment of Helicobacter pylori ulcer disease that has failed on other regimens (with pantoprazole and amoxicillin).

Action

Appears to inhibit DNA-dependent RNA polymerase in susceptible organisms.

Therapeutic effects

Antimycobacterial action against susceptible organisms.
Active against M. avium and most strains of M. tuberculosis.

Pharmacokinetics

Absorption: Well absorbed following oral administration (50–85%). Absorption is decreased in HIV-positive patients (20%).
Distribution: Widely distributed to body tissues and fluids.
Metabolism and Excretion: Mostly metabolized by the liver; <5% excreted unchanged by the kidneys.
Half-life: 45 hr.

Time/action profile (blood levels)

ROUTEONSETPEAKDURATION
POrapid2–4 hr24 hr

Contraindications/Precautions

Contraindicated in: Hypersensitivity. Cross-sensitivity with other rifamycins (rifampin) may occur;Active tuberculosis;Concurrent ritonavir or delavirdine.
Use Cautiously in: Obstetric / Lactation / Pediatric: Safety not established.

Adverse Reactions/Side Effects

Ear, Eye, Nose, Throat

  • brown-orange discoloration of tears (most frequent)
  • ocular disturbances

Respiratory

  • dyspnea

Cardiovascular

  • chest pain
  • chest pressure

Gastrointestinal

  • pseudomembranous colitis (life-threatening)
  • brown-orange discoloration of saliva (most frequent)
  • altered taste
  • drug-induced hepatitis

Genitourinary

  • brown-orange discoloration of urine (most frequent)

Dermatologic

  • rash
  • skin discoloration

Hematologic

  • hemolysis
  • neutropenia
  • thrombocytopenia

Musculoskeletal

  • arthralgia
  • myositis

Miscellaneous

  • brown-orange discoloration of body fluids (most frequent)
  • flu-like syndrome

Interactions

Drug-Drug interaction

Increases metabolism and may decrease the effectiveness of other drugs, including efavirenz, indinavir, nelfinavir, nevirapine, saquinavir (dosage adjustment may be necessary), delavirdine (concurrent use should be avoided), corticosteroids, disopyramide, quinidine, opioid analgesics, oral hypoglycemic agents, warfarin, estrogens, estrogen-containing contraceptives, phenytoin, verapamil, fluconazole, quinidine, theophylline, zidovudine, and chloramphenicol.Ritonavir increases blood levels of rifabutin (concurrent use is contraindicated), similar effects occur with efavirenz and nevirapine.

Route/Dosage

Oral (Adults) 300 mg once daily. If GI upset occurs, may give as 150 mg twice daily with food. H. pylori—300 mg/day (unlabeled).

Availability

Capsules: 150 mg

Nursing implications

Nursing assessment

  • Monitor patient for signs of active tuberculosis (purified protein derivative [PPD], chest x-ray, sputum culture, blood culture, urine culture, biopsy of suspicious lymph nodes) prior to and throughout therapy. Rifabutin must not be administered to patients with active tuberculosis.
  • Monitor bowel function. Diarrhea, abdominal cramping, fever, and bloody stools should be reported to health care professional promptly as a sign of pseudomembranous colitis. May begin up to several weeks following cessation of therapy.
  • Lab Test Considerations: Monitor CBC periodically during therapy. May cause neutropenia and thrombocytopenia.

Potential Nursing Diagnoses

Risk for infection (Indications)
Noncompliance (Patient/Family Teaching)

Implementation

  • Do not confuse rifabutin with rifampin.
  • Oral: May be administered without regard to meals. High-fat meals slow rate but not extent of absorption. May be mixed with foods such as applesauce. If GI upset occurs, administer with food.

Patient/Family Teaching

  • Advise patient to take medication as directed. Do not skip doses or double up on missed doses. Emphasize the importance of continuing therapy even if asymptomatic.
  • Advise patient to notify health care professional promptly if signs and symptoms of neutropenia (sore throat, fever, signs of infection), thrombocytopenia (unusual bleeding or bruising), or hepatitis (yellow eyes and skin, nausea, vomiting, anorexia, unusual tiredness, weakness) occur.
  • Caution patient to avoid the use of alcohol during this therapy, because this may increase the risk of hepatotoxicity.
  • Instruct patient to notify health care professional immediately if diarrhea, abdominal cramping, fever, or bloody stools occur and not to treat with antidiarrheals without consulting health care professionals.
  • Instruct patient to report symptoms of myositis (myalgia, arthralgia) or uveitis (intraocular inflammation) to health care professional promptly.
  • Inform patient that saliva, sputum, sweat, tears, urine, and feces may become red-orange to red-brown and that soft contact lenses may become permanently discolored.
  • Advise patient that this medication has teratogenic properties and may decrease the effectiveness of oral contraceptives. Counsel patient to use a nonhormonal form of contraception throughout therapy.
  • Emphasize the importance of regular follow-up exams to monitor progress and to check for side effects.

Evaluation/Desired Outcomes

  • Prevention of disseminated MAC in patients with advanced HIV infection.

Mycobutin®

Rifabutin, see there.

Mycobutin

A brand name for RIFABUTIN.
References in periodicals archive ?
For Bartonella, which is more common than Lyme and has more vectors than any infection on earth, people routinely experience treatment failures with azithromycin, levaquin, rifampin, Mycobutin, HBOT, herbal brews, and other options that are only judged to work if someone "feels better." The healers do not know how to use indirect testing to track Bartonella or Babesia, both of which have more species and strains emerging virtually every few months.
Combining nevirapine and rifabutin (Mycobutin) results in lower levels of both drugs.
Delavirdine should not be taken with the following: alprazolam (Xanax), midazolam (Versed), triazolam (Halcion), carbamazipine (Carbatrol, Tegretol, Tegretol XR), phenobarbital, phenytoin (Dilantin), cisapride (Propulsid), cimetidine (Tagamet), famotidine (Pepcid), nizatidine (Axid), ranitidine (Zantac), rifampin (Rifadin, Rimactane) or rifabutin (Mycobutin).
Adria Laboratories will manufacture the drug under the brand name Mycobutin. MAC victims experience such conditions as fever, fatigue and weight loss.
I have found that Levaquin, rifampin, Zithromax, doxycycline, Mycobutin, Cumunda, Banderol, and Rife machines at various frequencies and power may lower body load and lead to initial feelings of improvement.
Levels of rifabutin (Mycobutin) are also reduced by efavirenz and an increase in dose of rifabutin to 450 mg should be considered.
Saquinavir should not be taken with the following: cisapride (Propulsid), triazolam (Halcion), midazolam (Versed), ergot derivatives (Wigraine and Cafergot), simvastatin (Zocor), lovastatin (Mevacor), rifampin (Rifadin, Rimactane), rifabutin (Mycobutin), efavirenz (Sustiva) and indinavir (Crixivan), which is antagonistic in vivo.
When administered concomitantly with ritonavir, the dose of rifabutin (Mycobutin) should be reduced to 150 mg once daily.
Similarly the dose of rifabutin (Mycobutin) should be reduced by 50% when used with indinavir.