Rifampin 300mg Capsules

Rifampin inhibits bacterial DNA-dependent RNA polymerase activity by binding to the beta subunit of the enzyme. This binding prevents the initiation of transcription, thereby inhibiting bacterial RNA synthesis and ultimately protein synthesis. It is bactericidal against susceptible organisms.

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 immediately or seek emergency medical attention:

Signs of an allergic reaction: rash, hives, itching, redness, swelling, blistering, or peeling skin (with or without fever), wheezing, tightness in the chest or throat, difficulty breathing, swallowing, or speaking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat.
Signs of liver problems: dark urine, fatigue, decreased appetite, stomach upset or pain, light-colored stools, vomiting, or yellow skin and eyes.
Signs of kidney problems: inability to urinate, changes in urine output, blood in the urine, or sudden 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 on the skin.
Changes in balance or coordination.
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).

New or Worsening Symptoms: Contact Your Doctor

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.

Antibiotic-Associated Diarrhea

Diarrhea is a common side effect of antibiotics. However, in rare cases, a severe form of diarrhea called Clostridioides difficile-associated diarrhea (CDAD) may occur. This condition can lead to life-threatening bowel problems. If you experience stomach pain, cramps, or loose, watery, or bloody stools, contact your doctor immediately. Do not treat diarrhea without consulting your doctor first.

Severe Skin Reactions

This medication can cause severe skin reactions, including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and other serious conditions. These reactions can be life-threatening and may affect other organs. If you experience any of the following symptoms, seek medical help right away: red, swollen, blistered, or peeling skin; red or irritated eyes; sores in the mouth, throat, nose, eyes, genitals, or skin; fever; chills; body aches; shortness of breath; or swollen glands.

Blood Problems

In rare cases, this medication can cause severe and potentially life-threatening blood problems, such as thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS). If you experience any of the following symptoms, contact your doctor immediately: extreme fatigue or weakness, bruising or bleeding, dark urine or yellow skin and eyes, pale skin, changes in urine output, changes in vision, weakness or numbness on one side of the body, difficulty speaking or thinking, or changes in balance.

Other Side Effects

Most people do not experience severe side effects, but some may occur. If you experience any of the following side effects, contact your doctor if they bother you or do not go away:

Drowsiness.
Gas.
Diarrhea, stomach upset, or vomiting.
Heartburn.
Stomach cramps.
* Changes in the color of body fluids to orange or red.

Reporting Side Effects

If you have questions about side effects or want to report any side effects, contact your doctor or the FDA at 1-800-332-1088. You can also report side effects online at https://www.fda.gov/medwatch.

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 symptoms you experienced.
If you have previously taken this medication and it caused liver problems.
Any medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins, as some of these may interact with this medication. Specifically, certain medications used to treat HIV, infections, depression, and other conditions should not be taken with this drug. Your doctor or pharmacist can advise you on which medications are safe to take together.

Please note that this is not an exhaustive list of all potential drug interactions or health problems that may affect your use of this medication. To ensure your safety, it is crucial to:

Inform your doctor and pharmacist about all your medications (prescription and OTC), natural products, vitamins, and health problems.
Verify that it is safe to take this medication with all 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 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 assessments 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 medication may cause discoloration of contact lenses. Do not use this drug 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 they will need to discuss the potential benefits and risks of this medication to you and your baby.

• Protease Inhibitors (e.g., Atazanavir, Darunavir, Fosamprenavir, Lopinavir/Ritonavir, Saquinavir, Tipranavir) - significant decrease in PI concentrations.
• Non-nucleoside Reverse Transcriptase Inhibitors (NNRTIs) (e.g., Delavirdine, Rilpivirine) - significant decrease in NNRTI concentrations.
• Daclatasvir, Ledipasvir/Sofosbuvir, Ombitasvir/Paritaprevir/Ritonavir, Sofosbuvir/Velpatasvir, Voxilaprevir/Sofosbuvir/Velpatasvir (HCV antivirals) - significant decrease in antiviral concentrations.
• Praziquantel - significant decrease in praziquantel concentrations.
• Voriconazole - significant decrease in voriconazole concentrations.

• Oral Contraceptives - decreased efficacy, leading to contraceptive failure.
• Warfarin - decreased anticoagulant effect.
• Corticosteroids (e.g., Prednisone, Dexamethasone) - decreased corticosteroid effect.
• Cyclosporine, Tacrolimus, Sirolimus (Immunosuppressants) - decreased immunosuppressant levels, leading to transplant rejection.
• Digoxin - decreased digoxin levels.
• Phenytoin, Carbamazepine (Anticonvulsants) - decreased anticonvulsant levels, leading to loss of seizure control.
• Sulfonylureas (e.g., Glyburide, Glipizide) - decreased hypoglycemic effect.
• Methadone - decreased methadone levels, leading to withdrawal symptoms.
• Clarithromycin, Erythromycin - decreased macrolide levels.
• Fluconazole, Itraconazole, Ketoconazole, Posaconazole - decreased azole antifungal levels.
• Calcium Channel Blockers (e.g., Verapamil, Diltiazem, Nifedipine) - decreased antihypertensive effect.
• Beta-blockers (e.g., Metoprolol, Propranolol) - decreased beta-blocker effect.
• Amiodarone - decreased amiodarone levels.
• Statins (e.g., Simvastatin, Atorvastatin) - decreased statin levels, potentially leading to hyperlipidemia.
• Theophylline - decreased theophylline levels.
• Quinine - decreased quinine levels.
• Oral Hypoglycemics - decreased hypoglycemic effect.
• Dapsone - decreased dapsone levels.
• Chloramphenicol - decreased chloramphenicol levels.

• Acetaminophen - increased risk of hepatotoxicity with chronic use.
• Oral Anticoagulants (other than warfarin) - decreased anticoagulant effect.
• Propafenone - decreased propafenone levels.
• Quinidine - decreased quinidine levels.
• Tramadol - decreased tramadol levels.
• Zolpidem - decreased zolpidem levels.
• Buspirone - decreased buspirone levels.
• Clozapine - decreased clozapine levels.
• Haloperidol - decreased haloperidol levels.
• Olanzapine - decreased olanzapine levels.
• Risperidone - decreased risperidone levels.
• Sertraline - decreased sertraline levels.
• Tricyclic Antidepressants (e.g., Amitriptyline) - decreased antidepressant levels.
• Bupropion - decreased bupropion levels.
• Fentanyl - decreased fentanyl levels.
• Gabapentin - decreased gabapentin levels.
• Levothyroxine - decreased levothyroxine levels.
• Metformin - decreased metformin levels.
• Phenobarbital - decreased phenobarbital levels.
• Topiramate - decreased topiramate levels.
• Valproic Acid - decreased valproic acid levels.

• Not available (most interactions are significant due to strong enzyme induction).

• Flu-like syndrome (fever, chills, headache, dizziness, bone pain)
• Hepatotoxicity (fatigue, weakness, malaise, anorexia, nausea, vomiting, dark urine, jaundice, light-colored stools)
• Hypersensitivity reactions (rash, pruritus, urticaria, fever, eosinophilia)
• Thrombocytopenia (easy bruising, petechiae, purpura, bleeding)
• Hemolytic anemia
• Renal insufficiency (rare, acute tubular necrosis)
• Gastrointestinal upset (nausea, vomiting, abdominal pain, diarrhea)
• Orange-red discoloration of urine, sweat, tears, saliva, and contact lenses

Rifampin is classified as Pregnancy Category C. Studies in animals have shown adverse effects on the fetus, but 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. There is a theoretical risk of hemorrhagic disease in the newborn due to vitamin K deficiency if Rifampin is used in the last few weeks of pregnancy; vitamin K supplementation for the mother and/or newborn may be considered.

Rifampin is excreted into breast milk. The amount is generally considered small and unlikely to cause adverse effects in a breastfed infant. The American Academy of Pediatrics considers Rifampin compatible with breastfeeding. However, monitor the infant for potential side effects such as gastrointestinal upset (diarrhea, vomiting) or orange discoloration of urine/stools (though rare in infants).

Rifampin is commonly used in pediatric patients for the treatment of tuberculosis and other susceptible infections. Dosing is weight-based. Children are generally more tolerant of Rifampin than adults, but monitoring for hepatotoxicity is still important. The orange discoloration of body fluids should be explained to parents/guardians.

No specific dose adjustment is required based solely on age. However, geriatric patients may have age-related decreases in hepatic or renal function, or multiple comorbidities and polypharmacy, which may increase the risk of adverse effects (especially hepatotoxicity) and drug interactions. Close monitoring of liver function and drug interactions is essential.

• Always take Rifampin on an empty stomach (1 hour before or 2 hours after meals) for optimal absorption.
• Warn patients about the harmless but striking orange-red discoloration of urine, sweat, tears, saliva, and contact lenses. This can permanently stain soft contact lenses.
• Rifampin is a potent inducer of many CYP450 enzymes and P-glycoprotein, leading to numerous significant drug interactions. Always review the patient's full medication list.
• Counsel female patients on the decreased efficacy of hormonal contraceptives and advise using alternative non-hormonal birth control methods.
• Monitor liver function tests (LFTs) regularly, especially in patients with pre-existing liver disease, alcohol use, or those receiving other hepatotoxic drugs (e.g., isoniazid, pyrazinamide).
• Rifampin is almost always used in combination with other antitubercular drugs to prevent the development of resistance.
• Patients should be educated on the importance of adherence to the full course of therapy to prevent treatment failure and drug resistance.

• Isoniazid (INH)
• Pyrazinamide (PZA)
• Ethambutol (EMB)
• Streptomycin
• Other fluoroquinolones (e.g., Moxifloxacin, Levofloxacin) for drug-resistant TB
• Bedaquiline
• Delamanid
• Linezolid

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. If you have any questions or concerns about this medication, don't hesitate to discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When reporting the incident, be prepared to provide details about the medication taken, the amount, and the time it occurred.