Rifadin 300mg Capsules
It is used to treat TB (tuberculosis). It is used to stop the spread of meningitis in people who carry the bacteria but are not sick with the disease.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Antitubercular agent; Antibiotic
Pharmacologic Class
RNA polymerase inhibitor
Pregnancy Category
C
FDA Approved
Sep 1971
DEA Schedule
Not Controlled
Overview
What is this medicine?
Rifampin is an antibiotic used to treat serious bacterial infections, especially tuberculosis (TB). It works by stopping the growth of bacteria. It's also used to prevent certain types of meningitis or Haemophilus influenzae infections in people who have been exposed to them.
How to Use This Medicine
Taking Your Medication Correctly
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your medication and follow the instructions closely.
Take your medication on an empty stomach, either 1 hour before or 2 hours after a meal.
Swallow your medication with a full glass of water.
* Continue taking your medication as directed by your doctor or healthcare provider, even if you start to feel well.
If you are taking an antacid, be sure to take your medication at least 1 hour before taking the antacid.
Special Instructions for Liquid (Suspension) Formulation
If you have difficulty swallowing pills, your doctor or pharmacist can help you prepare a liquid (suspension) form of your medication. If a liquid formulation is prepared, shake it well before use. To ensure accurate dosing, measure the liquid carefully using the measuring device provided with your medication. If no device is provided, ask your pharmacist for a suitable measuring device.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, away from heat and light. Do not store your medication in a bathroom. If a liquid (suspension) formulation is prepared, you can store it at room temperature or in the refrigerator. Discard any unused portion of the liquid formulation after 4 weeks.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it is close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for a missed dose.
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your medication and follow the instructions closely.
Take your medication on an empty stomach, either 1 hour before or 2 hours after a meal.
Swallow your medication with a full glass of water.
* Continue taking your medication as directed by your doctor or healthcare provider, even if you start to feel well.
If you are taking an antacid, be sure to take your medication at least 1 hour before taking the antacid.
Special Instructions for Liquid (Suspension) Formulation
If you have difficulty swallowing pills, your doctor or pharmacist can help you prepare a liquid (suspension) form of your medication. If a liquid formulation is prepared, shake it well before use. To ensure accurate dosing, measure the liquid carefully using the measuring device provided with your medication. If no device is provided, ask your pharmacist for a suitable measuring device.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, away from heat and light. Do not store your medication in a bathroom. If a liquid (suspension) formulation is prepared, you can store it at room temperature or in the refrigerator. Discard any unused portion of the liquid formulation after 4 weeks.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it is close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for a missed dose.
Lifestyle & Tips
- Take on an empty stomach (1 hour before or 2 hours after meals) for best absorption.
- Do not stop taking this medication without consulting your doctor, even if you feel better, as this can lead to drug resistance.
- Rifampin can cause your urine, sweat, tears, and other body fluids to turn orange-red. This is harmless but can permanently stain soft contact lenses. Consider wearing glasses during treatment.
- Avoid alcohol while taking rifampin due to increased risk of liver problems.
- Rifampin can make birth control pills less effective. Use an alternative, non-hormonal method of birth control (e.g., condoms) while taking rifampin and for at least 1 month after stopping it.
- Inform all healthcare providers that you are taking rifampin, as it interacts with many other medications.
Available Forms & Alternatives
Available Strengths:
Generic Alternatives:
Dosing & Administration
Adult Dosing
Standard Dose:
Tuberculosis (TB): 10 mg/kg orally or IV once daily (max 600 mg/day) or 600 mg orally or IV 2-3 times weekly (intermittent dosing). Meningococcal prophylaxis: 600 mg orally every 12 hours for 2 days.
Condition-Specific Dosing:
Tuberculosis (TB):
600 mg orally or IV once daily or 2-3 times weekly (as part of a multi-drug regimen).
Meningococcal prophylaxis:
600 mg orally every 12 hours for 2 days.
Haemophilus influenzae type b (Hib) prophylaxis:
600 mg orally once daily for 4 days.
Pediatric Dosing
Neonatal:
Not established for routine use; consult infectious disease specialist. For TB: 10-20 mg/kg/day (max 600 mg/day).
Infant:
TB: 10-20 mg/kg/day (max 600 mg/day). Meningococcal prophylaxis: <1 month: 10 mg/kg/day for 2 days; âĨ1 month: 20 mg/kg/day for 2 days (max 600 mg/day). Hib prophylaxis: 20 mg/kg/day for 4 days (max 600 mg/day).
Child:
TB: 10-20 mg/kg/day (max 600 mg/day). Meningococcal prophylaxis: 20 mg/kg/day for 2 days (max 600 mg/day). Hib prophylaxis: 20 mg/kg/day for 4 days (max 600 mg/day).
Adolescent:
TB: 10-20 mg/kg/day (max 600 mg/day). Meningococcal prophylaxis: 600 mg orally every 12 hours for 2 days. Hib prophylaxis: 600 mg orally once daily for 4 days.
Dose Adjustments
Renal Impairment:
Mild:
No adjustment needed.
Moderate:
No adjustment needed.
Severe:
No adjustment needed for intermittent hemodialysis or peritoneal dialysis. For severe renal impairment (CrCl <10 mL/min), some sources suggest reducing dose to 600 mg 3 times weekly, but generally, no dose adjustment is required as it is primarily eliminated via bile.
Dialysis:
Not significantly removed by hemodialysis or peritoneal dialysis. No supplemental dose needed after dialysis.
Hepatic Impairment:
Mild:
Use with caution; monitor liver function closely.
Moderate:
Dose reduction may be necessary (e.g., 8 mg/kg/day or 450 mg/day). Monitor liver function closely.
Severe:
Contraindicated in severe hepatic disease or active hepatitis. If used, significant dose reduction and close monitoring are required.
Pharmacology
Mechanism of Action
Rifampin inhibits bacterial DNA-dependent RNA polymerase activity by binding to its beta subunit. This prevents the initiation of transcription, thereby blocking bacterial RNA synthesis and leading to bactericidal effects. It is highly active against Mycobacterium tuberculosis and many Gram-positive and some Gram-negative bacteria.
Pharmacokinetics
Absorption:
Bioavailability:
90-95%
Tmax:
2-4 hours
FoodEffect:
Food may decrease the extent and rate of absorption. Administer on an empty stomach (1 hour before or 2 hours after meals).
Distribution:
Vd:
0.9-1.2 L/kg
ProteinBinding:
75-90%
CnssPenetration:
Yes (achieves therapeutic concentrations in CSF, especially with inflamed meninges)
Elimination:
HalfLife:
3-5 hours (initial), decreases to 2-3 hours with repeated dosing due to autoinduction
Clearance:
Not available (variable due to autoinduction)
ExcretionRoute:
Primarily biliary/fecal (60-65%), renal (30%, mostly as metabolites)
Unchanged:
Approximately 6-15% (renal)
Pharmacodynamics
OnsetOfAction:
Rapid
PeakEffect:
2-4 hours (plasma concentration)
DurationOfAction:
Not directly applicable for single dose; bactericidal effect persists as long as concentrations are above MIC.
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention immediately:
Signs of an allergic reaction: rash, hives, itching, red, swollen, blistered, or peeling skin (with or without fever), wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat.
Signs of liver problems: dark urine, tiredness, decreased appetite, upset stomach or stomach pain, light-colored stools, vomiting, or yellow skin or eyes.
Signs of kidney problems: inability to pass urine, changes in urine output, blood in the urine, or significant weight gain.
Dizziness or fainting.
Flu-like symptoms.
Fever, chills, or sore throat; unexplained bruising or bleeding; or feeling extremely tired or weak.
Joint pain or swelling.
Muscle pain or weakness.
Chest pain.
Excessive sweating.
Abnormal heartbeat.
Swelling in the arms or legs.
Purple spots or redness of the skin.
Changes in balance.
Confusion, difficulty focusing, or changes in behavior.
Menstrual changes.
Changes in vision, eye pain, or severe eye irritation.
Changes in tooth color (which may be long-lasting).
If you experience any new or worsening symptoms, such as cough, fever, fatigue, weakness, shortness of breath, headache, pain, night sweats, swollen glands, decreased appetite, weight loss, or skin sores, contact your doctor right away.
Important Warnings
Diarrhea is a common side effect of antibiotics. However, in rare cases, a severe form called C. difficile-associated diarrhea (CDAD) may occur, which can lead to life-threatening bowel problems. If you experience stomach pain, cramps, or very loose, watery, or bloody stools, contact your doctor immediately. Do not treat diarrhea without consulting your doctor first.
Severe skin reactions, including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and other serious reactions, may occur. These reactions can be life-threatening and may affect other organs. Seek medical help immediately if you experience red, swollen, blistered, or peeling skin; red or irritated eyes; sores in your mouth, throat, nose, eyes, genitals, or skin; fever; chills; body aches; shortness of breath; or swollen glands.
Rare but potentially life-threatening blood problems, such as thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), may occur. Contact your doctor immediately if you experience extreme tiredness or weakness, bruising or bleeding, dark urine or yellow skin or eyes, pale skin, changes in urine output, changes in vision, changes in strength on one side of the body, trouble speaking or thinking, or changes in balance, or fever.
Other Possible Side Effects
While many people may not experience side effects or may only have mild side effects, it is essential to be aware of the following:
Drowsiness.
Gas.
Diarrhea, upset stomach, or vomiting.
Heartburn.
Stomach cramps.
* Changes in the color of body fluids to orange or red.
If any of these side effects or other symptoms bother you or do not go away, contact your doctor or seek medical attention.
Reporting Side Effects
You can report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention immediately:
Signs of an allergic reaction: rash, hives, itching, red, swollen, blistered, or peeling skin (with or without fever), wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat.
Signs of liver problems: dark urine, tiredness, decreased appetite, upset stomach or stomach pain, light-colored stools, vomiting, or yellow skin or eyes.
Signs of kidney problems: inability to pass urine, changes in urine output, blood in the urine, or significant weight gain.
Dizziness or fainting.
Flu-like symptoms.
Fever, chills, or sore throat; unexplained bruising or bleeding; or feeling extremely tired or weak.
Joint pain or swelling.
Muscle pain or weakness.
Chest pain.
Excessive sweating.
Abnormal heartbeat.
Swelling in the arms or legs.
Purple spots or redness of the skin.
Changes in balance.
Confusion, difficulty focusing, or changes in behavior.
Menstrual changes.
Changes in vision, eye pain, or severe eye irritation.
Changes in tooth color (which may be long-lasting).
If you experience any new or worsening symptoms, such as cough, fever, fatigue, weakness, shortness of breath, headache, pain, night sweats, swollen glands, decreased appetite, weight loss, or skin sores, contact your doctor right away.
Important Warnings
Diarrhea is a common side effect of antibiotics. However, in rare cases, a severe form called C. difficile-associated diarrhea (CDAD) may occur, which can lead to life-threatening bowel problems. If you experience stomach pain, cramps, or very loose, watery, or bloody stools, contact your doctor immediately. Do not treat diarrhea without consulting your doctor first.
Severe skin reactions, including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and other serious reactions, may occur. These reactions can be life-threatening and may affect other organs. Seek medical help immediately if you experience red, swollen, blistered, or peeling skin; red or irritated eyes; sores in your mouth, throat, nose, eyes, genitals, or skin; fever; chills; body aches; shortness of breath; or swollen glands.
Rare but potentially life-threatening blood problems, such as thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), may occur. Contact your doctor immediately if you experience extreme tiredness or weakness, bruising or bleeding, dark urine or yellow skin or eyes, pale skin, changes in urine output, changes in vision, changes in strength on one side of the body, trouble speaking or thinking, or changes in balance, or fever.
Other Possible Side Effects
While many people may not experience side effects or may only have mild side effects, it is essential to be aware of the following:
Drowsiness.
Gas.
Diarrhea, upset stomach, or vomiting.
Heartburn.
Stomach cramps.
* Changes in the color of body fluids to orange or red.
If any of these side effects or other symptoms bother you or do not go away, contact your doctor or seek medical attention.
Reporting Side Effects
You can report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Yellowing of the skin or eyes (jaundice)
- Dark urine or pale stools
- Persistent nausea, vomiting, or loss of appetite
- Unusual tiredness or weakness
- Abdominal pain, especially in the upper right side
- Flu-like symptoms (fever, chills, headache, muscle/joint aches) that are severe or persistent
- Skin rash, itching, or hives
- Unusual bleeding or bruising
- Swelling of the face, lips, tongue, or throat; difficulty breathing (signs of allergic reaction)
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have previously experienced liver problems while taking this medication.
Any medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This is crucial because certain medications, such as those used to treat HIV, infections, depression, and other conditions, should not be taken with this medication. Your doctor or pharmacist can advise you on potential interactions.
Please note that this is not an exhaustive list of all medications or health conditions that may interact with this medication.
To ensure your safety, it is vital to discuss all of your medications (prescription and OTC), natural products, vitamins, and health problems with your doctor and pharmacist. This will help determine whether it is safe to take this medication with your other medications and health conditions. Never start, stop, or change the dose of any medication without first consulting your doctor.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have previously experienced liver problems while taking this medication.
Any medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This is crucial because certain medications, such as those used to treat HIV, infections, depression, and other conditions, should not be taken with this medication. Your doctor or pharmacist can advise you on potential interactions.
Please note that this is not an exhaustive list of all medications or health conditions that may interact with this medication.
To ensure your safety, it is vital to discuss all of your medications (prescription and OTC), natural products, vitamins, and health problems with your doctor and pharmacist. This will help determine whether it is safe to take this medication with your other medications and health conditions. Never start, stop, or change the dose of any medication without first consulting your doctor.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Your doctor will likely recommend regular blood tests and other laboratory evaluations to monitor your condition. Be aware that this drug may interfere with certain lab tests, so it is crucial to notify all your healthcare providers and laboratory personnel that you are taking this medication.
To minimize potential risks, avoid consuming alcohol while taking this drug. If you have diabetes, it is vital to closely monitor your blood sugar levels, as this medication may affect them. Be aware of the signs of high blood sugar, such as confusion, drowsiness, increased thirst or hunger, frequent urination, flushing, rapid breathing, or fruity-smelling breath, and report them to your doctor promptly.
Additionally, this drug may cause discoloration of contact lenses. Do not use this medication for longer than prescribed, as this may increase the risk of a second infection.
Rifampin has been associated with liver problems, which can be severe and potentially life-threatening, especially in individuals with pre-existing liver disease or those taking other medications that may increase the risk of liver damage. If you have concerns, discuss them with your doctor.
This medication has also been linked to certain lung problems, which can be fatal. If you have questions or concerns, consult your doctor.
If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.
It is essential to note that birth control pills and other hormone-based contraceptives may be less effective while taking this drug. To prevent pregnancy, use an additional form of birth control, such as a condom.
If you are pregnant, plan to become pregnant, or are breastfeeding, inform your doctor, as you will need to discuss the potential benefits and risks of this medication to both you and your baby.
To minimize potential risks, avoid consuming alcohol while taking this drug. If you have diabetes, it is vital to closely monitor your blood sugar levels, as this medication may affect them. Be aware of the signs of high blood sugar, such as confusion, drowsiness, increased thirst or hunger, frequent urination, flushing, rapid breathing, or fruity-smelling breath, and report them to your doctor promptly.
Additionally, this drug may cause discoloration of contact lenses. Do not use this medication for longer than prescribed, as this may increase the risk of a second infection.
Rifampin has been associated with liver problems, which can be severe and potentially life-threatening, especially in individuals with pre-existing liver disease or those taking other medications that may increase the risk of liver damage. If you have concerns, discuss them with your doctor.
This medication has also been linked to certain lung problems, which can be fatal. If you have questions or concerns, consult your doctor.
If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.
It is essential to note that birth control pills and other hormone-based contraceptives may be less effective while taking this drug. To prevent pregnancy, use an additional form of birth control, such as a condom.
If you are pregnant, plan to become pregnant, or are breastfeeding, inform your doctor, as you will need to discuss the potential benefits and risks of this medication to both you and your baby.
Overdose Information
Overdose Symptoms:
- Nausea, vomiting, abdominal pain
- Lethargy, drowsiness
- Increased liver enzymes (transaminases)
- Jaundice (yellowing of skin/eyes)
- Orange-red discoloration of skin, urine, sweat, tears, and feces (more intense than usual therapeutic effect)
- Hepatomegaly (enlarged liver)
- In severe cases: loss of consciousness, convulsions, cardiac arrhythmias, cardiac arrest.
What to Do:
Seek immediate medical attention or call a poison control center (e.g., 1-800-222-1222). Treatment is supportive and symptomatic. Gastric lavage may be performed if ingestion is recent. Activated charcoal may be administered. Hemodialysis is generally not effective.
Drug Interactions
Contraindicated Interactions
- Protease inhibitors (e.g., atazanavir, darunavir, fosamprenavir, saquinavir, tipranavir) - due to significant decrease in antiretroviral concentrations.
- Non-nucleoside reverse transcriptase inhibitors (e.g., delavirdine, rilpivirine) - due to significant decrease in antiretroviral concentrations.
- Praziquantel - significantly reduces praziquantel levels.
- Voriconazole - significantly reduces voriconazole levels.
- Oral contraceptives - significant reduction in efficacy leading to contraceptive failure.
Major Interactions
- Warfarin (decreased anticoagulant effect)
- Oral hypoglycemics (decreased effect)
- Corticosteroids (decreased effect)
- Digoxin (decreased effect)
- Phenytoin (decreased effect)
- Theophylline (decreased effect)
- Cyclosporine, tacrolimus, sirolimus (decreased immunosuppressant effect)
- Calcium channel blockers (e.g., verapamil, diltiazem, nifedipine) (decreased effect)
- Beta-blockers (e.g., metoprolol, propranolol) (decreased effect)
- Statins (e.g., simvastatin, atorvastatin) (decreased effect)
- Antifungals (e.g., fluconazole, itraconazole, ketoconazole) (decreased effect)
- Methadone (withdrawal symptoms due to decreased levels)
- Clopidogrel (decreased antiplatelet effect)
- Dabigatran (decreased anticoagulant effect)
- Quinine (decreased effect)
- Selective serotonin reuptake inhibitors (SSRIs) (decreased effect)
- Tricyclic antidepressants (TCAs) (decreased effect)
- Buspirone (decreased effect)
- Zolpidem (decreased effect)
- Propafenone (decreased effect)
- Mexiletine (decreased effect)
- Amiodarone (decreased effect)
- Lidocaine (decreased effect)
- Quinidine (decreased effect)
- Dapsone (decreased effect)
- Chloramphenicol (decreased effect)
- Clarithromycin (decreased effect)
- Erythromycin (decreased effect)
- Telithromycin (decreased effect)
- Linezolid (decreased effect)
- Atovaquone (decreased effect)
- Sulfonylureas (decreased effect)
- Thiazolidinediones (decreased effect)
- Repaglinide (decreased effect)
- Nateglinide (decreased effect)
- Pioglitazone (decreased effect)
- Rosiglitazone (decreased effect)
- Ethosuximide (decreased effect)
- Valproic acid (decreased effect)
- Lamotrigine (decreased effect)
- Tiagabine (decreased effect)
- Topiramate (decreased effect)
- Zonisamide (decreased effect)
- Carbamazepine (decreased effect)
- Phenobarbital (decreased effect)
- Fentanyl (decreased effect)
- Alfentanil (decreased effect)
- Sufentanil (decreased effect)
- Tramadol (decreased effect)
- Oxycodone (decreased effect)
- Hydrocodone (decreased effect)
- Codeine (decreased effect)
- Morphine (decreased effect)
- Buprenorphine (decreased effect)
- Naloxone (decreased effect)
- Naltrexone (decreased effect)
- Benzodiazepines (e.g., midazolam, triazolam) (decreased effect)
- Buspirone (decreased effect)
- Zaleplon (decreased effect)
- Zopiclone (decreased effect)
- Eplerenone (decreased effect)
- Spironolactone (decreased effect)
- Furosemide (decreased effect)
- Hydrochlorothiazide (decreased effect)
- Amiloride (decreased effect)
- Triamterene (decreased effect)
- Sildenafil (decreased effect)
- Tadalafil (decreased effect)
- Vardenafil (decreased effect)
- Ranolazine (decreased effect)
- Ivabradine (decreased effect)
- Ticagrelor (decreased effect)
- Rivaroxaban (decreased effect)
- Apixaban (decreased effect)
- Edoxaban (decreased effect)
- Dronedarone (decreased effect)
- Rifabutin (increased rifabutin levels, potential for toxicity)
- Isoniazid (increased risk of hepatotoxicity)
Moderate Interactions
- Acetaminophen (increased risk of hepatotoxicity with chronic use)
- Alcohol (increased risk of hepatotoxicity)
- Grapefruit juice (may affect absorption, but less significant than other interactions)
- Food (decreased absorption if taken with food)
Minor Interactions
- Not available
Monitoring
Baseline Monitoring
Liver function tests (ALT, AST, bilirubin, alkaline phosphatase)
Rationale: Rifampin can cause hepatotoxicity, especially in patients with pre-existing liver disease or when co-administered with other hepatotoxic drugs.
Timing: Before initiation of therapy.
Complete Blood Count (CBC) with differential
Rationale: Rarely, rifampin can cause hematologic abnormalities (e.g., thrombocytopenia, leukopenia, hemolytic anemia).
Timing: Before initiation of therapy.
Renal function tests (BUN, creatinine)
Rationale: Although primarily eliminated hepatically, renal impairment can influence drug accumulation in severe cases.
Timing: Before initiation of therapy.
Routine Monitoring
Liver function tests (ALT, AST, bilirubin)
Frequency: Monthly or every 2-4 weeks during initial intensive phase of TB treatment, then as clinically indicated.
Target: Within normal limits or stable from baseline.
Action Threshold: Discontinue if ALT/AST >3-5 times ULN with symptoms, or >5 times ULN without symptoms. Re-evaluate if significant increases occur.
Clinical symptoms of hepatotoxicity (fatigue, weakness, nausea, vomiting, dark urine, jaundice, abdominal pain)
Frequency: Daily patient education and inquiry.
Target: Absence of symptoms.
Action Threshold: Prompt evaluation and discontinuation if symptoms appear.
CBC with differential
Frequency: Periodically, especially if patient develops fever, rash, or other signs of bone marrow suppression.
Target: Within normal limits.
Action Threshold: Discontinue if significant thrombocytopenia, leukopenia, or hemolytic anemia develops.
Therapeutic drug monitoring (TDM) for rifampin levels
Frequency: Not routinely recommended for all patients, but may be considered in specific populations (e.g., HIV co-infection, malabsorption, treatment failure, severe disease, or suspected non-adherence).
Target: Peak (2-4 hours post-dose) 8-24 mcg/mL.
Action Threshold: Adjust dose if levels are subtherapeutic or supratherapeutic.
Symptom Monitoring
- Signs of hepatotoxicity (yellowing of skin/eyes, dark urine, pale stools, persistent nausea/vomiting, unusual fatigue, abdominal pain)
- Flu-like syndrome (fever, chills, headache, muscle/joint pain)
- Skin rash, itching, hives
- Unusual bleeding or bruising (signs of thrombocytopenia)
- Shortness of breath, unusual weakness (signs of hemolytic anemia)
- Gastrointestinal upset (nausea, vomiting, diarrhea, abdominal cramps)
- Changes in vision or hearing (rare)
Special Patient Groups
Pregnancy
Rifampin is Pregnancy Category C. Studies in animals have shown adverse effects on the fetus. There are no adequate and well-controlled studies in pregnant women. It should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. It is generally considered part of standard TB treatment regimens during pregnancy due to the risks of untreated TB.
Trimester-Specific Risks:
First Trimester:
Potential for teratogenicity observed in animal studies (e.g., spina bifida, cleft palate). Human data are limited but do not show a consistent pattern of major malformations.
Second Trimester:
Generally considered safer than first trimester, but continued monitoring for maternal hepatotoxicity is crucial.
Third Trimester:
May cause postnatal hemorrhage in mother and/or infant due to interference with vitamin K metabolism. Vitamin K supplementation (e.g., 10 mg orally daily for mother during last month of pregnancy, and 1 mg IM for newborn at birth) is often recommended.
Lactation
Rifampin is excreted in breast milk. The amount transferred to the infant is small and generally not considered harmful. The American Academy of Pediatrics considers rifampin compatible with breastfeeding. Monitor breastfed infants for signs of adverse effects (e.g., poor feeding, jaundice, unusual lethargy).
Infant Risk:
Low risk. Potential for orange discoloration of urine/stools in infant. Theoretical risk of hepatotoxicity, but unlikely at typical breast milk concentrations. Benefits of breastfeeding generally outweigh risks.
Pediatric Use
Rifampin is widely used in pediatric populations for TB and prophylaxis. Dosing is weight-based. Children are generally more susceptible to drug-induced hepatitis than adults, but rifampin is usually well-tolerated. Close monitoring of liver function is important.
Geriatric Use
No specific dose adjustment is required based solely on age. However, elderly patients may have age-related decreases in hepatic or renal function, or may be on multiple medications, increasing the risk of adverse effects and drug interactions. Monitor liver function and for adverse effects closely.
Clinical Information
Clinical Pearls
- Rifampin is a potent inducer of many CYP450 enzymes and P-glycoprotein, leading to numerous significant drug interactions. Always review concomitant medications carefully.
- Counsel patients about the harmless but noticeable orange-red discoloration of body fluids (urine, sweat, tears, saliva, feces). Advise against wearing soft contact lenses.
- Emphasize the importance of adherence to the full course of therapy, especially for TB, to prevent drug resistance.
- Always use rifampin as part of a multi-drug regimen for active TB to prevent resistance.
- Monitor liver function tests regularly, especially in patients with pre-existing liver disease, alcohol use, or those taking other hepatotoxic drugs.
- Advise women of childbearing potential about the reduced efficacy of hormonal contraceptives and recommend alternative birth control methods.
Alternative Therapies
- For Tuberculosis: Isoniazid, Pyrazinamide, Ethambutol, Streptomycin, Bedaquiline, Delamanid, Pretomanid, Linezolid, Moxifloxacin, Levofloxacin, Amikacin, Kanamycin, Capreomycin.
- For Meningococcal/Hib prophylaxis: Ciprofloxacin (adults), Ceftriaxone (children/pregnant women).
Cost & Coverage
Average Cost:
Varies widely by pharmacy and dosage form (e.g., $50-$200+) per 30 capsules (300mg)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or 2 (Generic), Tier 3 (Brand)
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so it's a good idea to check with your pharmacist for more information. If you have any questions or concerns about this medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide details about the medication, including the amount taken and the time it happened, to help healthcare professionals provide the best possible care.