Rifampin (rifampin) - Dosing, PA Forms & Info (2026)
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    1. Home
    2. Rifampin - Rifampin injection, Powder, Lyophilized, For Solution

    Get your patient on Rifampin - Rifampin injection, Powder, Lyophilized, For Solution (Rifampin)

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    Prescribing informationPubMed™ news

    Rifampin - Rifampin injection, Powder, Lyophilized, For Solution prescribing information

    • Indications & usage
    • Dosage & administration
    • Contraindications
    • Adverse reactions
    • Drug interactions
    • Description
    • Pharmacology
    • How supplied/storage & handling
    • Mechanism of action
    • Data source
    • Indications & usage
    • Dosage & administration
    • Contraindications
    • Adverse reactions
    • Drug interactions
    • Description
    • Pharmacology
    • How supplied/storage & handling
    • Mechanism of action
    • Data source
    Prescribing Information
    Indications & Usage

    INDICATIONS AND USAGE

    In the treatment of both tuberculosis and the meningococcal carrier state, the small number of resistant cells present within large populations of susceptible cells can rapidly become the predominant type. Bacteriologic cultures should be obtained before the start of therapy to confirm the susceptibility of the organism to Rifampin for Injection, USP and they should be repeated throughout therapy to monitor the response to treatment.  Since resistance can emerge rapidly, susceptibility tests should be performed in the event of persistent positive cultures during the course of treatment. If test results show resistance to Rifampin for Injection, USP and the patient is not responding to therapy, the drug regimen should be modified.

    Tuberculosis

    Rifampin for Injection, USP is indicated in the treatment of all forms of tuberculosis.

    A three-drug regimen consisting of rifampin, isoniazid, and pyrazinamide is recommended in the initial phase of short-course therapy which is usually continued for 2 months. The Advisory Council for the Elimination of Tuberculosis, the American Thoracic Society, and Centers for Disease Control and Prevention recommend that either streptomycin or ethambutol be added as a fourth drug in a regimen containing isoniazid (INH), rifampin, and pyrazinamide for initial treatment of tuberculosis unless the likelihood of INH resistance is very low. The need for a fourth drug should be reassessed when the results of susceptibility testing are known. If community rates of INH resistance are currently less than 4%, an initial treatment regimen with less than four drugs may be considered.

    Following the initial phase, treatment should be continued with rifampin and isoniazid for at least 4 months. Treatment should be continued for longer if the patient is still sputum or culture positive, if resistant organisms are present, or if the patient is HIV positive.

    Rifampin for Injection, USP is indicated for the initial treatment and retreatment of tuberculosis when the drug cannot be taken by mouth.

    Meningococcal Carriers

    Rifampin for Injection, USP is indicated for the treatment of asymptomatic carriers of Neisseria meningitidis to eliminate meningococci from the nasopharynx. Rifampin is not indicated for the treatment of meningococcal infection because of the possibility of the rapid emergence of resistant organisms. (See WARNINGS.)

    Rifampin should not be used indiscriminately, and, therefore, diagnostic laboratory procedures, including serotyping and susceptibility testing, should be performed for establishment of the carrier state and the correct treatment. So that the usefulness of rifampin in the treatment of asymptomatic meningococcal carriers is preserved, the drug should be used only when the risk of meningococcal disease is high.

    To reduce the development of drug-resistant bacteria and maintain the effectiveness of rifampin and other antibacterial drugs, rifampin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria.  When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

    Dosage & Administration

    DOSAGE AND ADMINISTRATION

    Rifampin for Injection can be administered by IV infusion only (see INDICATIONS AND USAGE ). IV doses are the same as those for oral.

    See CLINICAL PHARMACOLOGY for dosing information in patients with renal failure.

    Tuberculosis

    Adults: 10 mg/kg, in a single daily administration, not to exceed 600 mg/day, oral or IV

    Pediatric Patients: 10-20 mg/kg, not to exceed 600 mg/day, oral or IV

    It is recommended that oral rifampin be administered once daily, either 1 hour before or 2 hours after a meal with a full glass of water.

    Rifampin is indicated in the treatment of all forms of tuberculosis. A three-drug regimen consisting of rifampin, isoniazid, and pyrazinamide is recommended in the initial phase of short-course therapy which is usually continued for 2 months. The Advisory Council for the Elimination of Tuberculosis, the American Thoracic Society, and the Centers for Disease Control and Prevention recommend that either streptomycin or ethambutol be added as a fourth drug in a regimen containing isoniazid (INH), rifampin, and pyrazinamide for initial treatment of tuberculosis unless the likelihood of INH resistance is very low. The need for a fourth drug should be reassessed when the results of susceptibility testing are known. If community rates of INH resistance are currently less than 4%, an initial treatment regimen with less than four drugs may be considered.

    Following the initial phase, treatment should be continued with rifampin and isoniazid for at least 4 months. Treatment should be continued for longer if the patient is still sputum or culture positive, if resistant organisms are present, or if the patient is HIV positive.

    Preparation of Solution for IV Infusion : Reconstitute the lyophilized powder by transferring 10 mL of sterile water for injection to a vial containing 600 mg of rifampin for injection. Swirl vial gently to completely dissolve the antibiotic. The reconstituted solution contains 60 mg rifampin per mL and is stable at room temperature for up to 30 hours. Prior to administration, withdraw from the reconstituted solution a volume equivalent to the amount of rifampin calculated to be administered and add to 500 mL of infusion medium. Mix well and infuse at a rate allowing for complete infusion within 3 hours. Alternatively, the amount of rifampin calculated to be administered may be added to 100 mL of infusion medium and infused in 30 minutes.

    Dilutions in dextrose 5% for injection (D5W) are stable at room temperature for up to 8 hours and should be prepared and used within this time. Precipitation of rifampin from the infusion solution may occur beyond this time. Dilutions in normal saline are stable at room temperature for up to 6 hours and should be prepared and used within this time. Other infusion solutions are not recommended.

    Incompatibilities : Physical incompatibility (precipitate) was observed with undiluted (5 mg/mL) and diluted (1 mg/mL in normal saline) diltiazem hydrochloride and rifampin (6 mg/mL in normal saline) during simulated Y-site administration.

    Meningococcal Carriers

    Adults: For adults, it is recommended that 600 mg rifampin be administered twice daily for two days.

    Pediatric Patients: Pediatric patients 1 month of age or older: 10 mg/kg (not to exceed 600 mg per dose) every 12 hours for two days.

    Pediatric patients under 1 month of age: 5 mg/kg every 12 hours for two days.

    Contraindications

    CONTRAINDICATIONS

    Rifampin is contraindicated in patients with a history of hypersensitivity to rifampin or any of the components, or to any of the rifamycins. (See WARNINGS .)

    Rifampin is contraindicated in patients who are also receiving ritonavir-boosted saquinavir due to an increased risk of severe hepatocellular toxicity. (See PRECAUTIONS, Drug Interactions .)

    Rifampin is contraindicated in patients who are also receiving atazanavir, darunavir, fosamprenavir, saquinavir, or tipranavir due to the potential of rifampin to substantially decrease plasma concentrations of these antiviral drugs, which may result in loss of antiviral efficacy and/or development of viral resistance.

    Rifampin is contraindicated in patients receiving praziquantel since therapeutically effective blood levels of praziquantel may not be achieved. In patients receiving rifampin who need immediate treatment with praziquantel alternative agents should be considered. However, if treatment with praziquantel is necessary, rifampin should be discontinued 4 weeks before administration of praziquantel. Treatment with rifampin can then be restarted one day after completion of praziquantel treatment.

    Adverse Reactions

    ADVERSE REACTIONS

    Gastrointestinal

    Heartburn, epigastric distress, anorexia, nausea, vomiting, jaundice, flatulence, cramps, and diarrhea have been noted in some patients. Although Clostridium difficile has been shown in vitro to be sensitive to rifampin, pseudomembranous colitis has been reported with the use of rifampin (and other broad spectrum antibiotics). Therefore, it is important to consider this diagnosis in patients who develop diarrhea in association with antibiotic use. Tooth discoloration (which may be permanent) may occur.

    Hepatic

    Hepatotoxicity including transient abnormalities in liver function tests (e.g., elevations in serum bilirubin, alkaline phosphatase, serum transaminases, gamma-glutamyl transferase), hepatitis, a shock-like syndrome with hepatic involvement and abnormal liver function tests, and cholestasis have been reported (see WARNINGS ).

    Hematologic

    Thrombocytopenia has occurred primarily with high dose intermittent therapy, but has also been noted after resumption of interrupted treatment. It rarely occurs during well-supervised daily therapy. This effect is reversible if the drug is discontinued as soon as purpura occurs. Cerebral hemorrhage and fatalities have been reported when rifampin administration has been continued or resumed after the appearance of purpura.

    Rare reports of disseminated intravascular coagulation have been observed.

    Leukopenia, hemolytic anemia, decreased hemoglobin, bleeding, and vitamin K–dependent coagulation disorders (abnormal prolongation of prothrombin time or low vitamin K–dependent coagulation factors) have been observed.

    Agranulocytosis has been reported very rarely.

    Central Nervous System

    Headache, fever, drowsiness, fatigue, ataxia, dizziness, inability to concentrate, mental confusion, behavioral changes, muscular weakness, pains in extremities, and generalized numbness have been observed.

    Psychoses have been rarely reported.

    Rare reports of myopathy have also been observed.

    Ocular

    Visual disturbances have been observed.

    Endocrine

    Menstrual disturbances have been observed.

    Rare reports of adrenal insufficiency in patients with compromised adrenal function have been observed.

    Renal

    Elevations in BUN and serum uric acid have been reported. Rarely, hemolysis, hemoglobinuria, hematuria, interstitial nephritis, acute tubular necrosis, renal insufficiency, and acute renal failure have been noted. These are generally considered to be hypersensitivity reactions. They usually occur during intermittent therapy or when treatment is resumed following intentional or accidental interruption of a daily dosage regimen, and are reversible when rifampin is discontinued and appropriate therapy instituted.

    Dermatologic

    Cutaneous reactions are mild and self-limiting and do not appear to be hypersensitivity reactions. Typically, they consist of flushing and itching with or without a rash. More serious cutaneous reactions which may be due to hypersensitivity occur but are uncommon.

    Hypersensitivity Reactions

    Occasionally, pruritus, urticaria, rash, pemphigoid reaction, erythema multiforme, acute generalized exanthematous pustulosis, Stevens-Johnson Syndrome, toxic epidermal necrolysis, Drug Reaction with Eosinophilia and Systemic Symptoms syndrome (see WARNINGS ), vasculitis, eosinophilia, sore mouth, sore tongue, and conjunctivitis have been observed.

    Anaphylaxis has been reported rarely.

    Miscellaneous

    Paradoxical drug reaction has been reported with Rifampin for Injection (see WARNINGS ). Edema of the face and extremities has been reported. Other reactions which have occurred with intermittent dosage regimens include "flu syndrome" (such as episodes of fever, chills, headache, dizziness, and bone pain), shortness of breath, wheezing, decrease in blood pressure and shock. The "flu syndrome" may also appear if rifampin is taken irregularly by the patient or if daily administration is resumed after a drug-free interval.

    To report SUSPECTED ADVERSE REACTIONS, contact Hikma Pharmaceuticals USA Inc. at 1-877-845-0689 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch

    Drug Interactions

    Drug Interactions

    Pharmacodynamic interactions

    Healthy subjects who received rifampin 600 mg once daily concomitantly with saquinavir 1000 mg/ritonavir 100 mg twice daily (ritonavir-boosted saquinavir) developed severe hepatocellular toxicity. Therefore, concomitant use of these medications is contraindicated. (See CONTRAINDICATIONS .)

    When Rifampin is given concomitantly with other hepatotoxic medications such as halothane or isoniazid, the potential for hepatotoxicity is increased. The concomitant use of rifampin and halothane should be avoided. Patients receiving both rifampin and isoniazid should be monitored closely for hepatotoxicity.

    Effect of rifampin on other drugs

    Induction of Drug Metabolizing Enzymes and Transporters

    Drug metabolizing enzymes and transporters affected by rifampin include cytochromes P450 (CYP) 1A2, 2B6, 2C8, 2C9, 2C19, and 3A4, UDP-glucuronyltransferases (UGT), sulfotransferases, carboxylesterases, and transporters including P-glycoprotein (P-gp) and multidrug resistance-associated protein 2 (MRP2). Most drugs are substrates for one or more of these enzyme or transporter pathways and these pathways may be induced by rifampin simultaneously. Therefore, rifampin may increase the metabolism and decrease the activity of certain coadministered drugs or increase the activity of a coadministered pro-drug (where metabolic activation is required), and has the potential to perpetuate clinically important drug-drug interactions against many drugs and across many drug classes (Table 1).

    Table 1 summarizes the effect of rifampin on other drugs or drug classes. Adjust dosages of concomitant drugs based on approved drug labeling and if applicable, therapeutic drug monitoring, unless otherwise specified.

    Table1: Drug Interactions with Rifampin that Affect Concomitant Drug Concentrations a

    Drug or Drug Class and Prevention or Management

    Clinical Effect

    Antiretrovirals

    Prevention or Management: Concomitant use is contraindicated (See CONTRAINDICATIONS )

    Atazanavir

    Decrease AUC by 72%

    Darunavir b

    Substantial decrease in exposure, which may result in loss of therapeutic effect and development of resistance.

    Tipranavir

    Fosamprenavir c

    Decrease AUC by 82%

    Saquinavir

    Decrease AUC by 70%

    Coadministration may result in severe hepatocellular toxicity

    Antiretrovirals

    Prevention or Management: Avoid concomitant use

    Zidovudine

    Decrease AUC by 47%

    Indinavir

    Decrease AUC by 92%

    Efavirenz

    Decrease AUC by 26 %

    Hepatitis C Antiviral

    Prevention or Management: Avoid concomitant use

    Daclatasvir

    Decrease AUC by 79%

    Simeprevir

    Decrease AUC by 48%

    Sofosbuvir b

    Decrease AUC by 72% Coadministration of sofosbuvir with rifampin, may decrease sofosbuvir plasma concentrations, leading to reduced therapeutic effect of sofosbuvir.

    Telaprevir

    Decrease AUC by 92%

    Systemic Hormonal Contraceptives

    Prevention or Management: Advise patients to change to non-hormonal methods of birth control during rifampin therapy

    Estrogens

    Decrease exposure

    Progestins

    Anticonvulsants

    Phenytoin d

    Decrease exposure d

    Antiarrhythmics

    Disopyramide

    Decrease exposure

    Mexiletine

    Decrease exposure

    Quinidine

    Decrease exposure

    Propafenone

    Decrease AUC by 50%-67%

    Tocainide

    Decrease exposure

    Antiestrogens

    Tamoxifen

    Decrease AUC by 86%

    Toremifene

    Decrease steady state concentrations of toremifene in serum

    Antithrombotic Agents

    Clopidogrel
    Prevention or Management:
    Concomitant use of clopidogrel and rifampin should be discouraged

    Increase active metabolite exposure and risk of bleeding

    Ticagrelor
    Prevention or Management: Avoid use
    Decrease exposure

    Antipsychotics

    Haloperidol

    Decrease plasma concentrations by 70%

    Oral Anticoagulants

    Prevention or Management: Perform prothrombin time daily or as frequently as necessary to establish and maintain the required dose of anticoagulant

    Warfarin

    Decrease exposure

    Antifungals

    Fluconazole

    Decrease AUC by 23%

    Itraconazole

    Prevention or Management: Not recommended 2 weeks before and during itraconazole treatment

    Decrease exposure

    Ketoconazole

    Decrease exposure

    Beta-blockers

    Metoprolol

    Decrease exposure

    Propranolol

    Decrease exposure

    Benzodiazepines

    Diazepam a,e

    Decrease exposure

    Benzodiazepine-related drugs

    Zopiclone

    Decrease AUC by 82%

    Zolpidem

    Decrease AUC by 73%

    Calcium Channel Blockers e

    Diltiazem

    Decrease exposure

    Nifedipine f

    Decrease exposure

    Verapamil

    Decrease exposure

    Corticosteroids g

    Prednisolone

    Decrease exposure

    Cardiac Glycosides

    Digoxin

    Prevention or Management: Measure serum digoxin concentrations before initiating rifampin. Continue monitoring and increase digoxin dose by approximately 20%-40% as necessary.

    Decrease exposure

    Digitoxin

    Decrease exposure

    Fluoroquinolones

    Pefloxacin h

    Decrease exposure

    Moxifloxacin a,d

    Decrease exposure

    Oral Hypoglycemic Agents (e.g. sulfonylureas)

    Glyburide

    Decrease exposure

    Rifampin may worsen glucose control of glyburide

    Glipizide

    Decrease exposure

    Immunosuppressive Agents

    Cyclosporine

    Decrease exposure

    Tacrolimus

    Prevention or Management: Monitoring of whole blood concentrations and appropriate dosage adjustments of tacrolimus are recommended when rifampin and tacrolimus are used concomitantly.

    Decrease AUC by 56%

    Narcotic Analgesics

    Oxycodone

    Decrease AUC by 86%

    Morphine

    Decrease exposure

    Selective 5-HT3 Receptor Antagonists

    Ondansetron

    Decrease exposure

    Statins Metabolized by CYP3A4

    Simvastatin

    Decrease exposure

    Thiazolidinediones

    Rosiglitazone

    Decrease AUC by 66%

    Tricyclic Antidepressants

    Nortriptyline i

    Decrease exposure

    Other Drugs

    Enalapril

    Decrease active metabolite exposure

    Chloramphenicol j

    Decrease exposure

    Clarithromycin

    Decrease exposure

    Dapsone

    Decrease exposure

    Doxycycline k

    Decrease exposure

    Irinotecan l

    Prevention or Management: Avoid the use of rifampin, strong CYP3A4 inducer, if possible. Substitute non-enzyme inducing therapies at least 2 weeks prior to initiation of irinotecan therapy

    Decrease irinotecan and active metabolite exposure

    Levothyroxine

    Decrease exposure

    Losartan

    Parent

    Decrease AUC by 30%

    Active metabolite (E3174)

    Decrease AUC by 40%.

    Methadone

    In patients well-stabilized on methadone, concomitant administration of rifampin resulted in a marked reduction in serum methadone levels and a concurrent appearance of withdrawal symptoms.

    Praziquantel

    Prevention or Management: Concomitant use is contraindicated (See CONTRAINDICATIONS )

    Decrease plasma praziquantel concentrations to undetectable levels.

    Quinine

    Prevention or Management: Avoid concomitant use

    Decrease AUC by 75%-85%

    Telithromycin

    Decrease AUC by 86%

    Theophylline

    Decrease exposure by 20% to 40%

    a Administered with rifampin 600 mg daily, unless otherwise specified

    b Rifampin dosage used concomitantly with the drug(s) is not specified in the proposed package insert.

    c Administered with rifampin 300 mg daily

    d Administered with rifampin 450 mg daily

    e Administered with rifampin 1200 mg daily

    f Rifampin 1200 mg administered as a single oral dose 8 hours before administering a single oral dose of nifedipine 10 mg

    g Numerous cases in the literature describe a decrease in glucocorticoid effect when used concomitantly with rifampin. The literature contains reports of acute adrenal crisis or adrenal insufficiency induced by the combination of rifampin-isoniazid-ethambutol or rifampin-isoniazid in patients with Addison’s disease

    h Administered with rifampin 900 mg daily

    i A tuberculosis treatment regimen including rifampin (600 mg/day), isoniazid (300 mg/day), pyrazinamide (500 mg 3× per day), and pyridoxine (25 mg) was associated with higher than expected doses of nortriptyline were required to obtain a therapeutic drug level. Following the discontinuation of rifampin, the patient became drowsy and the serum nortriptyline levels rose precipitously (3-fold) into the toxic range.

    j Concomitant use with rifampin in 2 children

    k Administered with rifampin (10 mg/kg daily)

    l Administered with an antibiotic regimen including rifampin (450 mg/day), isoniazid (300 mg/day), and streptomycin (0.5 g/day) IM

    AUC = area under the time-concentration curve

    Effect of other drugs on rifampin

    Concomitant antacid administration may reduce the absorption of rifampin. Daily doses of rifampin should be given at least 1 hour before the ingestion of antacids.

    Concomitant use with probenecid and cotrimoxazole increases the concentration of rifampin which may increase the risk of rifampin toxicities. Monitor for adverse reactions associated with Rifampin for Injection during coadministration.

    Other Interactions

    Atovaquone: Concomitant use of rifampin with atovaquone decrease concentrations of atovaquone and increase concentrations of rifampin which may increase the risk of Rifampin for Injection toxicities. Coadministration of rifampin with atovaquone is not recommended.

    Description

    DESCRIPTION

    Rifampin for Injection, USP contains rifampin 600 mg, sodium formaldehyde sulfoxylate 10 mg, and sodium hydroxide to adjust pH.

    Rifampin is a semisynthetic antibiotic derivative of rifamycin SV. Rifampin is a red-brown crystalline powder very slightly soluble in water at neutral pH, freely soluble in chloroform, soluble in ethyl acetate and in methanol. Its molecular weight is 822.95 and its chemical formula is C 43 H 58 N 4 O 12 . The chemical name for rifampin is either:

    3-[[(4-Methyl-1-piperazinyl)imino]methyl]rifamycin

    or

    5,6,9,17,19,21-hexahydroxy-23-methoxy-2,4,12,16,18, 20,22– heptamethyl-8-[N-(4-methyl-1-piperazinyl)formimidoyl]-2,7-(epoxypentadeca [1,11,13]trienimino)naphtho[2,1- b ]furan-1,11(2H)-dione 21-acetate.

    Its structural formula is:

    Referenced Image
    Pharmacology

    CLINICAL PHARMACOLOGY

    Intravenous Administration

    After intravenous administration of a 300 or 600 mg dose of rifampin infused over 30 minutes to healthy male volunteers (n=12), mean peak plasma concentrations were 9.0 ± 3.0 and 17.5 ± 5.0 mcg/mL, respectively. Total body clearances after the 300 and 600 mg IV doses were 0.19 ± 0.06 and 0.14 ± 0.03 L/hr/kg, respectively. Volumes of distribution at steady state were 0.66 ± 0.14 and 0.64 ± 0.11 L/kg for the 300 and 600 mg IV doses, respectively. After intravenous administration of 300 or 600 mg doses, rifampin plasma concentrations in these volunteers remained detectable for 8 and 12 hours, respectively (see Table).

    Plasma Concentrations (mean ± standard deviation, mcg/mL)
    Rifampin Dosage IV 30 min 1 hr 2 hr 4 hr 8 hr 12 hr
    300 mg 8.9 ± 2.9 4.9 ± 1.3 4.0 ± 1.3 2.5 ± 1.0 1.1 ± 0.6 <0.4
    600 mg 17.4 ± 5.1 11.7 ± 2.8 9.4 ± 2.3 6.4 ± 1.7 3.5 ± 1.4 1.2 ± 0.6

    Plasma concentrations after the 600 mg dose, which were disproportionately higher (up to 30% greater than expected) than those found after the 300 mg dose, indicated that the elimination of larger doses was not as rapid.

    After repeated once-a-day infusions (3-hr duration) of 600 mg in patients (n=5) for 7 days, concentrations of IV rifampin decreased from 5.81 ± 3.38 mcg/mL 8 hours after the infusion on day 1 to 2.6 ± 1.88 mcg/mL 8 hours after the infusion on day 7.

    Rifampin is widely distributed throughout the body. It is present in effective concentrations in many organs and body fluids, including cerebrospinal fluid. Rifampin is about 80% protein bound. Most of the unbound fraction is not ionized and therefore diffuses freely into tissues.

    Rifampin is rapidly eliminated in the bile and undergoes progressive enterohepatic circulation and deacetylation to the primary metabolite, 25-desacetyl-rifampin. This metabolite is microbiologically active. Less than 30% of the dose is excreted in the urine as rifampin or metabolites. Serum concentrations do not differ in patients with renal failure at a studied dose of 300 mg, and consequently, no dosage adjustment is required.

    Pediatrics

    Intravenous Administration . In pediatric patients 0.25 to 12.8 years old (n=12), the mean peak serum concentration of rifampin at the end of a 30-minute infusion of approximately 300 mg/m 2 was 25.9 ± 1.3 mcg/mL; individual peak concentrations 1 to 4 days after initiation of therapy ranged from 11.7 to 41.5 mcg/mL; individual peak concentrations 5 to 14 days after initiation of therapy were 13.6 to 37.4 mcg/mL. The individual serum half-life of rifampin changed from 1.04 to 3.81 hours early in therapy to 1.17 to 3.19 hours 5 to 14 days after therapy was initiated.

    Microbiology

    Mechanism of Action

    Rifampin inhibits DNA-dependent RNA polymerase activity in susceptible Mycobacterium tuberculosis organisms. Specifically, it interacts with bacterial RNA polymerase but does not inhibit the mammalian enzyme.

    Resistance

    Organisms resistant to rifampin are likely to be resistant to other rifamycins.

    In the treatment of both tuberculosis and the meningococcal carrier state (see INDICATIONS AND USAGE), the small number of resistant cells present within large populations of susceptible cells can rapidly become predominant. In addition, resistance to rifampin has been determined to occur as single-step mutations of the DNA-dependent RNA polymerase. Since resistance can emerge rapidly, appropriate susceptibility tests should be performed in the event of persistent positive cultures.

    Activity in vitro and in vivo

    Rifampin has bactericidal activity in vitro against slow and intermittently growing M. tuberculosis organisms.

    Rifampin has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections (see INDICATIONS AND USAGE ):

    Aerobic Gram-Negative Microorganisms:

    Neisseria meningitidis

    “Other” Microorganisms:

    Mycobacterium tuberculosis

    The following in vitro data are available, but their clinical significance is unknown .

    At least 90% of the following bacteria exhibit an in vitro minimum inhibitory concentration (MIC) less than or equal to the susceptible breakpoint for rifampin against isolates of similar genus or organism group. However, the efficacy of rifampin in treating clinical infections caused by these bacteria has not been established in adequate and well-controlled clinical trials

    Aerobic Gram-Positive Microorganisms: Staphylococcus aureus (including Methicillin-Resistant S. aureus /MRSA) Staphylococcus epidermidis

    Aerobic Gram-Negative Microorganisms:

    Haemophilus influenzae

    “Other” Microorganisms:

    Mycobacterium leprae

    ß-lactamase production should have no effect on rifampin activity.

    Susceptibility Testing

    For specific information regarding susceptibility test interpretive criteria and associated test methods and quality control standards recognized by FDA for this drug, please see: https://www.fda.gov/STIC .

    How Supplied/Storage & Handling

    HOW SUPPLIED

    Rifampin for Injection, USP is available in sterile glass vials containing 600 mg rifampin (NDC 0143-9230-01).

    Storage: Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature].  Avoid excessive heat (temperatures above 40°C or 104°F). Protect from light.

    Manufactured by:
    HIKMA FARMACÊUTICA (PORTUGAL), S.A.
    Estrada do Rio da Mó, 8, 8A e 8B  - Fervença  - 2705-906 Terrugem SNT, PORTUGAL

    Distributed by:

    Hikma Pharmaceuticals USA Inc.

    Berkeley Heights, NJ 07922

    Revised: December 2021

    PIN432-WES/7

    Mechanism of Action

    Mechanism of Action

    Rifampin inhibits DNA-dependent RNA polymerase activity in susceptible Mycobacterium tuberculosis organisms. Specifically, it interacts with bacterial RNA polymerase but does not inhibit the mammalian enzyme.

    Data SourceWe receive information directly from the FDA and PrescriberPoint is updated as frequently as changes are made available
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