Why it's used

Isoniazid/Rifampicin is a prescription medicine that is used to treat all forms of tuberculosis. This medicine works by destroying the bacteria that cause tuberculosis.
Anti-Tuberculosis Drugs
Isoniazid+Rifampicin belongs to the Anti-Tuberculosis Drugs class of medicines. Anti-tuberculosis drugs are used for the treatment of infectious tuberculosis.

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How to use

Read the medicine guide provided by your pharmacist, your doctor, or the medicine company. If you have any questions related to Isoniazid+Rifampicin, ask your doctor or pharmacist. Use Isoniazid/Rifampicin as per the instructions provided by your doctor.
Isoniazid+Rifampicin is eaten without food. This medicine should be given 2 hours after or 30 minutes before a meal. This medicine should be swallowed whole with water.

Typical Dosage

The typical dose of Isoniazid+Rifampicin for adults is 450 mg of rifampicin and 300 mg of isoniazid for patients weighing less than 50 kg (110.2 lb) and 600 mg of rifampicin and 300 mg of isoniazid for patients weighing more than or equal to 50 kg (110.2 lb).

Talk to Your Doctor

Discuss with your doctor if your condition does not improve or worsens. Discuss with your doctor if skin flushing, itching, irregular periods, constipation, diarrhea, stomach discomfort, dry mouth, headache, loss of appetite (anorexia), breast enlargement in men, increased thirst, going to the toilet more often, feeling tired, high blood sugar, acne, and inflammation of the blood vessels. If you have issues with the health of your liver, take a low dose of rifampicin with caution and close monitoring of liver function should be advised.

Use in Children

The safety and effectiveness of using Isoniazid/Rifampicin in children has not been established.

If Drinking Alcohol

Consult with your doctor on the consumption of alcohol with Isoniazid+Rifampicin. Avoid cheese and red wine while using Isoniazid+Rifampicin. Cheese and red wine contain tyramine which has interactions with Isoniazid+Rifampicin and may cause headache, sweating, palpitations, flushing, and low blood pressure. Avoid skipjack tuna or other tropical fish Histamine-containing foods such as skipjack tuna or other tropical fish, have interactions with Isoniazid+Rifampicin and may cause headache, sweating, palpitations, flushing, and low blood pressure.

Lab Tests

Your doctor may request that specific lab tests be performed before you start using Isoniazid/Rifampicin. Your doctor may ask you to undergo blood test. A blood test is needed before taking this medicine to check any changes in the blood after taking Isoniazid+Rifampicin.
Medicines may be recommended for uses other than those listed in the medicine guide. You should not use Isoniazid/Rifampicin for conditions or symptoms for which it was not prescribed. Do not give Isoniazid/Rifampicin to other people, even if they have the same conditions or symptoms that you have. The use of this medicine without the advice of a doctor may cause harm.

Storage

Follow storage instructions on the product package if available. Store Isoniazid/Rifampicin below 25°C (77°F), and away from moisture. Store this medicine away from children and pets.

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How to take Isoniazid+Rifampicin

The dose and frequency of using Isoniazid+Rifampicin will depend on the following factors:
  • the weight of the patient
  • the health of the patient's kidneys

Isoniazid+Rifampicin Dosage

Dosage for tuberculosis

Adult
  • Recommended: 450 mg of rifampicin and 300 mg of isoniazid for patients weighing less than 50 kg (110.2 lb) and 600 mg of rifampicin and 300 mg of isoniazid for patients weighing more than or equal to 50 kg (110.2 lb)
Older Adults
  • Recommended: 450 mg of rifampicin and 300 mg of isoniazid for elderly patients weighing less than 50 kg (110.2 lb) and 600 mg of rifampicin and 300 mg of isoniazid for elderly patients weighing more than or equal to 50 kg (110.2 lb)

Forms

Coated Tablet
Strength: 150 mg of rifampicin with 100 mg of isoniazid and 300 mg of rifampicin with 150 mg of isoniazid

Special Instructions

Elderly patients
Take necessary precautions while using Isoniazid+Rifampicin in elderly patients with liver dysfunction.

Missed Dose

Take the missed dose as soon as you remember. Skip the missed dose if it's time for the next dose. Avoid taking a double dose to make up for the missed dose.

Overdose

What to do if you overdose on Isoniazid+Rifampicin?
In case of overdose, close supervision and supportive care should be provided. Stomach emptying should be performed by cleaning out the contents of the stomach or by using charcoal, a substance that absorbs poisons from the stomach. Also, provide treatment with antiemetic medicines to avoid severe nausea and vomiting to such patients. Vitamin B6 should be given into the vein to patients with an overdose of isoniazid. If seizures remain after treatment with vitamin B6, provide anticonvulsant therapy. Sodium bicarbonate should be advised to control increased acid production. The Isoniazid+Rifampicin should be removed from the body by blood purifying technique (called as, dialysis) along with increased urine production by diuretics and fluids.
Symptoms of an overdose of Isoniazid+Rifampicin
If you use too much of this medicine, it could lead to dangerous levels of the medicine in your body. In such cases, symptoms of an overdose may include:
If you think you have overdosed on Isoniazid/Rifampicin, call a poison control center immediately. You can look up the poison control center information from the Poison Center Finder at TabletWise.com.

Precautions while using Isoniazid+Rifampicin

Before you use Isoniazid+Rifampicin, tell your doctor of your medical and health history including the following:
  • a black or Hispanic woman
  • a rare blood problem (known as porphyria)
  • a tendency to bruise easily
  • an HIV infection
  • diabetes
  • having more than 600 mg rifampicin daily
  • inject yourself with drugs
  • kidney problems
  • liver problems
  • mental health problems (such as depression or schizophrenia)
  • seizure
  • underweight
  • weakness, pain, and numbness from nerve damage (peripheral neuropathy)
  • wear contact lenses
  • your body needs a long time period to get rid of some medicines (a slow acetylator status)
This medicine may permanently stain soft contact lenses and cause difficulty to control diabetes.
Before you use Isoniazid+Rifampicin, tell your doctor if you are allergic to it or its ingredients. Your doctor may prescribe an alternative medicine and update your medical records to record this information.
The use of Isoniazid/Rifampicin may change blood pressure. This medicine may decrease blood pressure levels.
The use of this medicine may change blood bilirubin level. The blood bilirubin level may get increase while using this medicine.
The use of Isoniazid/Rifampicin may change liver enzyme levels. This medicine may increase the level of liver enzymes (aspartate aminotransferase and alanine aminotransferase).
The use of this medicine may change blood creatinine level. Isoniazid+Rifampicin may increase the blood creatinine level.

Use when Pregnant

Isoniazid+Rifampicin should be used only when required in patients who are pregnant or planning to become pregnant. There are no well-controlled investigations of rifampicin, and no isoniazid-related birth defects have been found in pregnant women. Therefore, Isoniazid+Rifampicin can be used during pregnancy only if the possible benefits outweigh the potential risk to the baby.

If Breastfeeding

Women who are breastfeeding should not use this medicine. Isoniazid+Rifampicin may pass into breast milk. So, the baby should not breastfeed by the mother receiving Isoniazid+Rifampicin unless in the doctor's judgment for the possible benefits to the mother outweigh the possible risk to the baby.

If trying to Conceive

Consult with your doctor on the use of Isoniazid+Rifampicin, if you are trying to conceive.

Alcohol

Consult with your doctor if you can drink alcohol while using Isoniazid+Rifampicin. Consumption of alcohol may cause inflammation of the liver.

Seizures

Isoniazid+Rifampicin can make you feel sleepy. Be careful, especially while driving, while using heavy machinery, or when doing any activity that needs you to be completely alert. The consumption of alcohol with Isoniazid+Rifampicin can worsen the sleepiness. Isoniazid+Rifampicin may cause seizures in some people. Hence, you should discuss with your doctor before performing any activities where a loss of consciousness may cause harm to you or others.

Increase in Risk

This medicine may cause stomach bleeding. Regular use of tobacco or alcohol may increase the risk. Discuss with your doctor if you smoke and drink alcohol regularly.

What precautions should be taken during Pregnancy and Nursing, and administering Isoniazid+Rifampicin to Children or the Older Adults?

Pregnant Women

Only When Necessary
Warning: Isoniazid+Rifampicin can be used during pregnancy only if the possible benefits outweigh the potential risk to the baby as there are no well-controlled investigations of rifampicin, and no isoniazid-related birth defects have been found in pregnant women.

Breastfeeding

Contraindicated or Not Recommended
Warning: The baby should not breastfeed by the mother receiving Isoniazid+Rifampicin unless in the doctor's judgment for the possible benefits to the mother outweigh the possible risk to the baby.

Younger Adults Population

Precaution
Warning: Take necessary precautions while using this medicine in children under the age of two years.

Older Adults Population

Precaution
Warning: It is advised to use caution while using this medicine in elderly patients especially if there are chances of liver dysfunction.

Isoniazid+Rifampicin Side-effects

The following side-effects may commonly occur when using Isoniazid/Rifampicin. If any of these side-effects worsen or last for a long time, you should consult with your doctor:
  • chills
  • dizziness
  • fever
  • headache
  • increased level of blood bilirubin
  • increased level of liver enzymes (alanine aminotransferase, aspartate aminotransferase)
  • low level of blood platelets with or without red-colored spots on the skin
  • nausea
  • vomiting
Rarely, the use of Isoniazid/Rifampicin may cause the following side-effects:
  • abnormal functioning of the immune system (pemphigoid)
  • acne
  • an increase or decrease in the amount of urine
  • black or tarry stools
  • bone pain
  • bone pain
  • cold clammy skin
  • damage of eye nerves (optic atrophy)
  • decreased appetite
  • difficulty sleeping
  • distorted vision
  • dry mouth
  • enlargement of the male breast (gynecomastia)
  • fatigue
  • feeling irritable or depressed
  • feeling nervous
  • feeling of discomfort
  • feeling of tenderness
  • feeling sick
  • flu (influenza)
  • flushing
  • going to toilet more often
  • hives
  • increased level of white blood cells (eosinophilia)
  • increased thirst
  • inflammation of the nerves of the eyes (optic neuritis)
  • itching
  • loss of tendon reflexes
  • memory loss
  • menstrual disorder
  • mouth ulcers
  • muscle weakness
  • night sweats
  • pain or discomfort in the right abdomen
  • severe headache
  • sore throat
  • sputum discoloration
  • stomach discomfort
  • sweat discoloration
  • swelling in the stomach
  • swelling of lips, throat, face or tongue
  • swelling of the ankles, legs or feet
  • tear discoloration
  • tingling sensation
  • tiredness
  • tooth discoloration
  • unable to focus
  • urine discoloration (chromaturia)
  • vertigo
  • weakness, pain, and numbness from nerve damage (polyneuritis)
  • weight loss
The following severe side-effects may also occur when using Isoniazid/Rifampicin:
  • If this happens, stop using this medicine and go to a hospital right away.
  • Blood vessel disorders
    Symptoms: shock, flushing, inflammation of blood vessels (vasculitis) bleeding
    If you experience any of these symptoms, contact your doctor.
  • Nervous system disorders (possibly fatal)
    Symptoms: bleeding inside the brain (cerebral hemorrhage), seizures, brain disorder (toxic encephalopathy) drug induced psychosis (toxic psychosis)
    If this happens, stop using this medicine and go to a hospital right away.
  • Symptoms: low level of blood platelets with or without red-colored spots on the skin, decrease in white blood cells count (leukopenia), formation of small blood clots throughout the bloodstream (disseminated intravascular coagulation), very low count of white blood cells, anemia due to the abnormal breakdown of red blood cells (hemolytic anemia), blood clotting disorder (vitamin k dependent coagulation disorders), anemia body stops producing new blood cells (aplastic anemia)
    If this happens, stop using this medicine and go to the hospital right away.
  • Infections
    Symptoms: inflammation of the colon (pseudomembranous colitis), severe watery diarrhea fever
    If this happens, talk to your doctor right away.
  • Stomach and intestinal disorders
    Symptoms: vomiting, diarrhea, constipation inflammation of the pancreas (pancreatitis)
    Call your doctor as soon as possible if you experience any of these symptoms.
  • Liver disorders (possibly fatal)
    Symptoms: inflammation of the liver high blood bilirubin level in the blood (hyperbilirubinemia)
    If you experience any of these symptoms contact your doctor as soon as possible.
  • Kidney disorder
    If this happens, stop using this medicine and go to a hospital right away.
  • General disorders
    Symptoms: fever swelling due to fluid accumulation
    If this happens, stop using this medicine and go to a hospital right away.
  • Metabolism and nutrition disorders
    Symptoms: high blood sugar level
    If this happens, ask your doctor right away.
Your doctor has prescribed this Isoniazid+Rifampicin because they have judged that the benefits outweigh the risks posed by side-effects. Many people using this medicine do not have serious side-effects. This is not a complete list of possible side-effects for Isoniazid+Rifampicin.
If you experience side-effects or notice other side-effects not listed above, contact your doctor for medical advice. You may also report side-effects to your local food and drug administration authority. You can look up the drug authority contact information from the Drug Authority Finder at TabletWise.com.

Side-effects and Allergic Reactions of Isoniazid+Rifampicin by Severity and Frequency

Common Side-effects

Following are the common side-effects of this medicine:

Infrequent and Rare Side-effects

Following are the infrequent and rare side-effects of this medicine:

Severe Side-effects

Following are the severe side-effects of this medicine:

Mild Allergic Reactions

Following are the symptoms of mild allergic reactions to this medicine:
  • flu-like symptoms
  • reddish circular patches with central blisters
  • skin peeling
  • swelling of the lips, throat, face or tongue

Serious Allergic Reactions

Following are the symptoms of serious allergic reactions to this medicine:
  • breathing problems
  • drug reaction with eosinophilia and systemic symptoms (DRESS)
  • drug-induced severe allergic reaction (toxic epidermal necrolysis)
  • fever
  • rash
  • severe allergic reaction (Stevens-Johnson syndrome)
  • severe drug-related skin reaction (acute generalized exanthematous pustulosis)
  • severe skin reaction (erythema multiforme)
  • skin redness or peeling (exfoliative dermatitis)
  • swallowing problems
  • ulcers of throat, mouth, nose, genitals, and eyes
  • wheezing
If this happens, stop using this medicine and go to a hospital right away.
If you experience side-effects or notice other side-effects not listed above, contact your doctor for medical advice. You may also report side-effects to your local food and drug administration authority. You can look up the drug authority contact information from the Drug Authority Finder at TabletWise.com.

Warnings

Bleeding Disorder

Patients using this medicine are at increased risk. These patients may suffer from severe bleeding, vitamin k dependent bleeding disorder. The patient should be monitored for the occurrence of a bleeding disorder. If required the supplements of vitamin k should be considered.

Medical Conditions

Patients with seizure disorder (epilepsy), slow acetylator status, history of numb or weak in your arms and legs (peripheral neuropathy), psychosis, diabetes, HIV infection, alcohol dependence or a rare blood problem (porphyria) are at increased risk when using this medicine. These patients should be carefully monitored.

Liver Dysfunction

Patients who use alcohol, being a Hispanic or black woman and patients with severe liver disease or using drugs into the vein are at increased risk when using this medicine. These patients may suffer from liver disorders. In such cases, low dose of rifampicin should be used. Patients should be observed weekly for two weeks, later every two weeks for the following six weeks during this treatment and should be questioned about the symptoms related to side effects. The level of liver enzymes, bilirubin, blood creatinine, and a complete blood count should also be monitored. Stop using rifampicin if symptoms of liver damage occur.

Genetic Problems

Patients with genetic problems including fructose intolerance, decreased absorption of glucose-galactose, and sucrase-isomaltase insufficiency are at increased risk when using this medicine. These patients should not use this medicine.

High Levels of Bilirubin in the Blood

Patients using this medicine are at increased risk. This medicine may cause increased blood bilirubin level.

Severe Skin Reaction

Patients using this medicine are at increased risk. These patients may suffer from severe skin allergic reactions, that can be life-threatening or possibly fatal. Symptoms such as fever, abnormalities of lymph nodes or liver abnormalities may be present in such patients. The patient is advised to monitor closely for the symptoms of skin reactions. If the symptoms are present, then the treatment with this medicine should be stopped and consult your doctor immediately. An alternative treatment should be considered.

Worsening of Blood Disorder

Patients using this medicine are at increased risk. The use of this medicine may cause worsening of blood disorder and discoloration of the teeth, sweat, urine, sputum, and tears. This medicine may permanently stain soft contact lenses.

Interactions with Isoniazid+Rifampicin

When two or more medicines are taken together, it can change how the medicines work and increase the risk of side-effects. In medical terms, this is called as a Drug Interaction.
This page does not contain all the possible interactions of Isoniazid/Rifampicin. Share a list of all medicines that you use with your doctor and pharmacist. Do not start, stop, or change the dose of any medicines without the approval of your doctor.

Cytochrome P-450 Enzyme

Isoniazid/Rifampicin interacts with Cytochrome P-450 enzyme. Take necessary precautions while using Isoniazid+Rifampicin with drugs that breakdown by cytochrome P-450. The dose of these drugs should be adjusted when starting or stopping treatment with Isoniazid+Rifampicin.

Antiretroviral Drugs

There may be an interaction of Isoniazid+Rifampicin with Antiretroviral drugs (saquinavir, ritonavir), which are used to treat HIV/AIDS. When saquinavir and ritonavir is used with Isoniazid+Rifampicin may increase the risk of liver damage. Therefore, Isoniazid+Rifampicin should not be used in combination with saquinavir/ritonavir.

Food Interaction

Isoniazid/Rifampicin may interact with Tyramine and histamine-containing foods. Cheese, red wine containing tyramine foods and histamine-containing foods such as skipjack tuna or other tropical fish have interactions with Isoniazid+Rifampicin and may cause headache, sweating, palpitations, flushing, and low blood pressure. Foods containing tyramine and histamine should be avoided in patients taking Isoniazid+Rifampicin.

Antibiotics

Your doctor's guidelines may need to be followed while taking this medicine along with Antibiotic such as cefazolin, which is used to treat bacterial infections. Severe fatal blood clotting disorders may occur while using other antibiotics such as cefazolin with rifampicin. The combined use of Isoniazid+Rifampicin with other antibiotics should be avoided.

Anesthetics

Special instructions need to be followed while taking this medicine along with Anesthetic such as halothane, which is used to induce loss of consciousness. Patients may experience an increased risk of liver damage while using Isoniazid+Rifampicin with an anesthetic such as halothane. Therefore, Isoniazid+Rifampicin should not be used in combination with an anesthetic.

Antiviral Drugs

Your doctor's guidelines may need to be followed while taking this medicine along with Antiviral drugs (daclatasvir, sofosbuvir, or telaprevir), which are used to treat viral infections. The use of Isoniazid+Rifampicin with hepatitis-C antiviral drugs should be avoided.

Antihypertensives

Special instructions need to be followed while taking this medicine along with Antihypertensive such as enalapril, which is used to treat high blood pressure. There is a decrease in active metabolite exposure of enalapril while using with Isoniazid+Rifampicin. The dose of Isoniazid+Rifampicin should be adjusted depending upon the patient's medical condition.

Drug Breakdown Enzymes and Transporters

Isoniazid/Rifampicin interacts with drug breakdown enzymes and transporters. Isoniazid+Rifampicin may affect the enzymes and transporters such as UDP-glucuronyltransferases (UGT), cytochromes P450 (CYP) 1A2, 2B6, 2C8, 2C9, 2C19, 3A4, carboxylesterases, sulfotransferases, and transporters including multidrug resistance-associated protein 2 (MRP2) and P-glycoprotein (P-gp).

Naphthoquinones

There may be an interaction of Isoniazid+Rifampicin with Naphthoquinone such as atovaquone, which is used to treat or prevent pneumonia. An increased amount of rifampicin and decreased amount of atovaquone has been observed while taking both medicines at the same time.

Antacids

Isoniazid/Rifampicin may interact with Antacids, which are used to treat stomach acidity. The absorption of Isoniazid+Rifampicin may get decreased while using an antacid. Rifampicin should be taken 1 hour before the use of antacids.

Antituberculosis Drugs

Your doctor's guidelines may need to be followed while taking this medicine along with Antituberculosis drugs (para-aminosalicylic acid, cycloserine), which are used to treat tuberculosis. The use of cycloserine with isoniazid may increase the risk of side effects of the central nervous system. Para-aminosalicylic acid and rifampicin should be given not less than eight hours apart to ensure adequate blood levels.

Methylxanthines

Special instructions need to be followed while taking this medicine along with Methylxanthine such as theophylline, which is used to treat respiratory diseases. With the use of isoniazid, the amount of theophylline in the blood may get increased.

Antifungals

Isoniazid/Rifampicin interacts with Antifungal such as ketoconazole, which is used to treat fungal infections. The amount of ketoconazole in the blood may get decreased while using with isoniazid.

Oral Contraceptives

There may be an interaction of Isoniazid+Rifampicin with Oral contraceptives, which are used to control pregnancy. Isoniazid+Rifampicin therapy may decrease the amount of oral contraceptives in the blood. Patients taking oral contraceptives should change to other birth control methods from a hormonal method while on Isoniazid+Rifampicin therapy.

Analgesics

Isoniazid/Rifampicin may interact with Analgesic such as morphine, which is used to treat pain. Rifampicin may decrease the amount of morphine in the blood. Monitor the analgesic effect of the morphine and adjust the doses of morphine during and after rifampicin therapy.

Interactions of Isoniazid+Rifampicin by Severity

Severe

The following medicines are usually not to be taken together without consulting with your doctor or pharmacist.

Serious

The following medicines may interact when taken together and can cause harmful effects in the body. Please consult with your doctor or pharmacist before taking these medicines together.

Moderate

The following medicines may interact when taken together and can increase your risk of harmful effects. Please consult with your doctor or pharmacist before taking these medicines together.

When should Isoniazid+Rifampicin be not used?

Allergy

This medicine should not be used in patients with known allergic reaction to it or any of its components.

Jaundice

Use of Isoniazid+Rifampicin is not recommended in patients having jaundice. These patients may have the following symptoms if they use this medicine:
  • yellowing of the skin and eyes

Combined Therapy with Saquinavir/Ritonavir

This medicine should not be used in combination with saquinavir and ritonavir. The risk of liver damage gets increased by using this combination.

Genetic Problems

Patients with genetic problems including fructose intolerance, decreased absorption of glucose-galactose, and sucrase-isomaltase insufficiency should not use this medicine.

Traveling With Medication

  • Ensure that you carry enough doses of each of your prescription medicines to last the entire trip. The best place to store your medicines is in the carry on baggage. However, while flying, if carrying liquid medicines, make sure you do not go over the limits imposed for carry-on liquids.
  • While traveling overseas, make sure that you can carry each of your prescription medicines legally to your destination country. One way to ensure this is by checking with your destination country's embassy or website.
  • Make sure that you carry each of your medicines in their original packaging, which should typically include your name and address, and the details of the prescribing doctor.
  • If your travel involves crossing time zones, and you are required to take your medicine as per a fixed schedule, make sure that you adjust for the change in time.

Expired Medication

Taking a single dose of expired Isoniazid+Rifampicin is unlikely to cause a side-effect. However, please discuss with your doctor or pharmacist, if you feel unwell or sick. An expired medicine may become ineffective in treating your prescribed conditions. To be on the safe side, it is important not to use an expired drug. You are much safer by always keeping a fresh supply of unexpired medicines.

Safe Disposal of Medication

  • If there are disposal instructions on the package, please follow the instructions.
  • If there are medicine take-back programs in your country, you should contact the respective authority to arrange for the disposal of the medicine. For example, in the USA, the Drug Enforcement Administration regularly hosts National Prescription Drug Take-Back events.
  • If there are no take-back programs, mix the medicine with dirt and place them in a sealed plastic bag. Throw the plastic bag in your household trash. Separately, remove all personal information including the prescription label from the medicine packaging and then dispose off the container.
  • If specifically indicated on the medicine package that it needs to be flushed down the toilet when no longer needed, perform the required step.
This page provides information for Isoniazid/Rifampicin .
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