Tibinide (Isoniazid)
Antitubercular medication for the treatment and prevention of tuberculosis
Tibinide contains isoniazid (INH), one of the most important first-line medications in the global fight against tuberculosis (TB). Used for both treating active TB and preventing latent TB infection, isoniazid works by specifically targeting and killing Mycobacterium tuberculosis bacteria. It is almost always prescribed as part of a multi-drug regimen to prevent resistance.
Quick Facts
Key Takeaways
- Tibinide (isoniazid) is a critical first-line drug for treating and preventing tuberculosis, listed on the WHO Model List of Essential Medicines.
- It must be taken on an empty stomach (at least 1 hour before or 2 hours after meals) for optimal absorption.
- Liver function should be monitored regularly during treatment, as hepatotoxicity is a serious potential side effect.
- Pyridoxine (vitamin B6) supplementation is recommended to prevent peripheral neuropathy, the most common side effect.
- Alcohol must be strictly avoided during treatment due to increased risk of liver damage and reduced drug efficacy.
What Is Tibinide and What Is It Used For?
Tibinide belongs to the group of antitubercular drugs and contains the active substance isoniazid (INH), which was first introduced in 1952 and remains one of the cornerstones of tuberculosis therapy worldwide. Isoniazid is a highly selective bactericidal agent, meaning it kills bacteria rather than merely inhibiting their growth, and it acts exclusively against Mycobacterium tuberculosis and closely related mycobacteria.
The mechanism of action of isoniazid is unique and highly specific. It acts as a prodrug that must first be activated by the mycobacterial enzyme catalase-peroxidase (KatG). Once activated, isoniazid inhibits the synthesis of mycolic acids, which are long-chain fatty acids essential for the structural integrity of the mycobacterial cell wall. Without mycolic acids, the bacterial cell wall becomes permeable and the organism dies. This mechanism explains why isoniazid is effective only against mycobacteria and has no significant activity against other bacterial species.
Isoniazid is particularly effective against actively dividing (replicating) bacteria during the early, intensive phase of tuberculosis treatment. It achieves rapid early bactericidal activity, meaning it kills large numbers of TB bacteria within the first few days of treatment. This property makes it invaluable in reducing the bacterial load quickly, which helps prevent transmission and improve clinical outcomes.
Indications for Use
Tibinide is prescribed for the following clinical situations:
- Active pulmonary tuberculosis: As part of a standard multi-drug regimen (typically with rifampicin, pyrazinamide, and ethambutol) for the treatment of confirmed or suspected pulmonary TB.
- Extrapulmonary tuberculosis: As part of combination therapy for TB affecting other organs, including lymph nodes, bones, meninges, kidneys, and other sites.
- Latent tuberculosis infection (LTBI) prophylaxis: As monotherapy or in combination with rifapentine for preventing latent TB from progressing to active disease, particularly in high-risk individuals such as close contacts of TB patients, immunosuppressed individuals, and healthcare workers.
- Drug-resistant TB: May be included in modified treatment regimens depending on the resistance pattern identified by drug sensitivity testing.
Tibinide is almost always used in combination with other antitubercular drugs when treating active TB. Using isoniazid alone to treat active TB carries a high risk of developing drug resistance. Monotherapy is only appropriate for latent TB infection prophylaxis.
According to the World Health Organization (WHO), isoniazid is on the Model List of Essential Medicines and is considered indispensable for the global control of tuberculosis. The WHO estimates that approximately 10.6 million people worldwide develop active TB each year, and isoniazid-containing regimens remain the standard of care in the vast majority of cases.
What Should You Know Before Taking Tibinide?
Contraindications
You should not take Tibinide in the following circumstances:
- Allergy to isoniazid or any other ingredient in the tablet (microcrystalline cellulose, stearic acid, talc, silicon dioxide).
- Active liver disease or existing liver damage, as isoniazid is metabolised in the liver and can cause further hepatotoxicity.
- Previous severe adverse reaction to isoniazid, including fever, chills, or drug-induced arthritis during prior treatment.
- History of severe skin reactions to isoniazid, such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), or DRESS syndrome.
Warnings and Precautions
Speak with your doctor before taking Tibinide if you have, or have had, any of the following conditions:
- Impaired kidney function: The dose of Tibinide may need to be reduced in patients with renal impairment, as the drug and its metabolites are partially excreted through the kidneys.
- Impaired liver function: Even subclinical liver disease increases the risk of isoniazid-induced hepatotoxicity. Baseline liver function tests (LFTs) should be performed before initiating treatment, and monitoring should continue at regular intervals.
- Epilepsy: Isoniazid can lower the seizure threshold, and the risk of convulsions is higher in patients with epilepsy or a history of seizures.
- Diabetes mellitus: Isoniazid can make blood glucose control more difficult. Diabetic patients may require closer monitoring and adjustment of their diabetes medications.
- History of psychosis: The risk of psychotic episodes or relapse may be increased during isoniazid treatment.
- Slow acetylator status: Individuals who metabolise isoniazid slowly (genetically determined) are at higher risk for peripheral neuropathy and hepatotoxicity.
Severe, potentially life-threatening skin reactions have been reported with isoniazid, including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalised exanthematous pustulosis (AGEP). Stop taking Tibinide and seek immediate medical attention if you develop a widespread rash, skin blistering, peeling skin, mouth ulcers, or a rash accompanied by fever.
Isoniazid can cause serious, potentially fatal liver damage. Early signs include yellowing of the skin or eyes, dark urine, pale stools, abdominal tenderness, nausea, loss of appetite, and unusual fatigue. Contact your doctor immediately if any of these symptoms occur. The risk of hepatotoxicity increases with age (especially over 35 years), daily alcohol consumption, and concurrent use of other hepatotoxic drugs.
Cross-Sensitivity
If you are hypersensitive to ethionamide, pyrazinamide, or niacin (nicotinic acid), you may also be hypersensitive to isoniazid. Inform your doctor about any known drug allergies before starting treatment.
Pregnancy and Breastfeeding
If you are pregnant, breastfeeding, think you may be pregnant, or are planning to have a baby, consult your doctor before taking Tibinide. Isoniazid crosses the placenta and is excreted in breast milk. However, the WHO recommends that pregnant women with active tuberculosis should be treated, as untreated TB poses a greater risk to both mother and child than the medication. Pyridoxine supplementation is particularly important during pregnancy.
The decision to treat with isoniazid during pregnancy should be made on a case-by-case basis, weighing the benefits of TB treatment or prophylaxis against the potential risks. According to current international guidelines (WHO, ATS/IDSA), isoniazid is generally considered safe in pregnancy when clinically indicated.
Driving and Operating Machinery
Tibinide has no known or negligible effect on the ability to drive vehicles or operate machinery under normal conditions. However, some patients may experience dizziness, confusion, or visual disturbances as side effects. If you are affected, do not drive or operate machinery until these symptoms resolve.
Alcohol
Alcohol consumption must be avoided during treatment with Tibinide. Alcohol reduces the therapeutic effectiveness of isoniazid and significantly increases the risk of hepatotoxicity (liver damage). The combination can lead to serious, potentially fatal liver injury.
Tyramine-Containing Foods
Foods containing high levels of tyramine may cause transient symptoms during Tibinide treatment, including facial flushing, palpitations, irregular heartbeat, and elevated blood pressure. These reactions typically occur within 30 minutes to 2 hours of eating and usually resolve within 2 to 4 hours. Isoniazid has mild monoamine oxidase inhibitor (MAOI) properties, which account for this interaction.
Foods to limit or avoid include aged cheeses, cured and fermented meats (salami, pepperoni), fermented soy products, sauerkraut, certain types of beer and wine, and pickled or smoked fish. Your doctor can provide more specific dietary guidance.
How Does Tibinide Interact with Other Drugs?
Isoniazid is metabolised primarily by N-acetyltransferase 2 (NAT2) in the liver, and it also inhibits several cytochrome P450 enzymes. This means it can significantly alter the blood levels and effects of many other drugs. The rate at which an individual metabolises isoniazid (fast or slow acetylator status) can influence both efficacy and the likelihood of interactions.
Major Interactions
The following drugs have clinically significant interactions with isoniazid and require careful monitoring or dose adjustments:
| Drug | Effect | Clinical Action |
|---|---|---|
| Rifampicin | Both drugs are hepatotoxic; combined use increases the risk of liver damage | Monitor liver function closely; essential combination for TB therapy |
| Phenytoin | Isoniazid inhibits phenytoin metabolism, raising serum levels and toxicity risk | Monitor phenytoin levels; dose reduction may be needed |
| Carbamazepine | Increased carbamazepine levels and risk of toxicity | Monitor drug levels and signs of toxicity |
| Warfarin | Isoniazid can enhance anticoagulant effect, increasing bleeding risk | Monitor INR closely; adjust warfarin dose as needed |
| Paracetamol (Acetaminophen) | Isoniazid induces CYP2E1, increasing formation of toxic paracetamol metabolites | Use lowest effective dose; avoid chronic use |
| Disulfiram | May cause coordination difficulties, psychotic episodes, or behavioural changes | Avoid combination if possible; monitor closely |
| Ketoconazole | Isoniazid may reduce ketoconazole serum levels | Monitor antifungal efficacy; consider alternative |
| Methotrexate | Additive hepatotoxicity risk | Enhanced liver function monitoring required |
Minor Interactions
| Drug | Effect | Clinical Action |
|---|---|---|
| Benzodiazepines (diazepam, midazolam, triazolam) | Increased sedative effect due to reduced metabolism | Monitor for excessive sedation; adjust dose if needed |
| Theophylline | Isoniazid may increase theophylline levels | Monitor theophylline levels; adjust dose as needed |
| Levodopa | Isoniazid may reduce levodopa effectiveness | Monitor Parkinson's symptom control |
| Aluminium-containing antacids | Reduced isoniazid absorption | Take antacids at least 1 hour after isoniazid |
| Prednisolone | Corticosteroids may reduce isoniazid serum levels | Monitor treatment response |
| Alfentanil | Increased alfentanil effect due to reduced metabolism | Monitor for excessive sedation during/after surgery |
| Sulfasalazine | Potential for additive hepatotoxicity | Monitor liver function |
| Haloperidol | Isoniazid may increase haloperidol serum levels | Monitor for extrapyramidal symptoms |
Always inform your healthcare provider about all medications you are currently taking, have recently taken, or plan to take, including prescription drugs, over-the-counter medicines, herbal supplements, and vitamins. Other drugs not listed here may also interact with isoniazid.
What Is the Correct Dosage of Tibinide?
Always take Tibinide exactly as your doctor has prescribed. Do not change the dose or stop treatment without consulting your healthcare provider. Tuberculosis treatment requires strict adherence to the full course of therapy to ensure cure and prevent the development of drug-resistant TB.
Adults
Active Tuberculosis (Combination Therapy)
Standard dose: 5 mg/kg/day (maximum 300 mg/day) as part of a multi-drug regimen.
Intensive phase (months 1–2): Isoniazid + rifampicin + pyrazinamide + ethambutol, taken daily.
Continuation phase (months 3–6): Isoniazid + rifampicin, taken daily.
Intermittent dosing (DOT): 15 mg/kg (maximum 900 mg) two or three times weekly under directly observed therapy.
Latent TB Infection Prophylaxis
Standard regimen: 5 mg/kg/day (maximum 300 mg/day) for 6 to 9 months.
Alternative short-course: Isoniazid + rifapentine once weekly for 12 weeks (3HP regimen) under directly observed therapy.
Children
Paediatric Dosing
Active TB: 10 mg/kg/day (range 7–15 mg/kg/day, maximum 300 mg/day).
Latent TB prophylaxis: 10 mg/kg/day (maximum 300 mg/day) for 6 to 9 months.
Important: Tibinide 300 mg tablets should not be given to children weighing less than 21 kg, as the necessary dose adjustment is not possible with this formulation. Suitable paediatric formulations should be used instead.
Elderly
Elderly Patients
The standard adult dose applies, but elderly patients (over 65 years) are at significantly increased risk for hepatotoxicity. More frequent liver function monitoring is recommended, particularly during the first 3 months of treatment. Dose reduction may be necessary in patients with impaired renal or hepatic function.
How to Take Tibinide
- Swallow the tablets whole with a glass of water or another suitable beverage.
- Take on an empty stomach — at least 1 hour before or 2 hours after a meal for optimal absorption.
- Take at the same time each day to maintain consistent blood levels.
- Do not crush, chew, or break the tablets unless specifically instructed by your doctor.
Missed Dose
If you forget to take a dose, take it as soon as you remember. However, if it is less than 6 hours until your next scheduled dose, skip the missed dose and take the next one at the usual time. Do not take a double dose to make up for a forgotten tablet. Consistent adherence is critical for TB treatment success.
Overdose
Isoniazid overdose is a medical emergency. Symptoms can include seizures (which may be refractory to standard anticonvulsants), metabolic acidosis, hyperglycaemia, and coma. If you or someone else has taken too much Tibinide, contact emergency services or your local poison control centre immediately. Pyridoxine (vitamin B6) given intravenously is the specific antidote for isoniazid overdose — the dose of pyridoxine should equal the amount of isoniazid ingested (gram for gram).
Stopping Treatment
Always complete the full course of treatment as prescribed, even if you start feeling better. Stopping isoniazid prematurely can allow surviving TB bacteria to multiply and develop resistance, making the infection much harder to treat. Always consult your doctor before discontinuing Tibinide. Premature discontinuation of TB treatment is one of the leading causes of multidrug-resistant tuberculosis (MDR-TB) globally.
What Are the Side Effects of Tibinide?
Like all medicines, Tibinide can cause side effects, although not everybody gets them. The frequency and severity of side effects depend on the dose, duration of treatment, individual metabolism (acetylator status), age, and concurrent medications.
Contact your doctor or go to the nearest emergency department immediately if you experience any of the following: severe abdominal pain radiating to the back (pancreatitis), yellowing of the skin or eyes (hepatitis), widespread skin peeling or blistering (SJS/TEN), rash with fever and organ involvement (DRESS), red pustular rash with fever (AGEP), or signs of severe allergic reaction (anaphylaxis) including swelling of lips/tongue, difficulty breathing, or collapse.
Very Common
Affects more than 1 in 10 people
- Peripheral neuropathy — numbness, tingling, or burning sensation in the hands and feet. Risk is reduced by concurrent pyridoxine (vitamin B6) supplementation.
- Elevated liver enzymes (transaminases) — often asymptomatic and detected on blood tests.
Uncommon
Affects 1 in 100 to 1 in 1,000 people
- Seizures (convulsions) or encephalopathy
- Memory disturbances or psychosis
- Hepatitis — clinically significant liver inflammation with jaundice (occurs in up to 1 in 100 patients)
Rare
Affects fewer than 1 in 1,000 people
- Toxic epidermal necrolysis (TEN) — severe skin and mucous membrane detachment
- DRESS syndrome — drug reaction with eosinophilia and systemic symptoms
Frequency Not Known
Cannot be estimated from available data
- Pancreatitis — inflammation of the pancreas causing severe abdominal and back pain
- Stevens-Johnson syndrome (SJS) — severe skin and mucous membrane reaction
- Acute generalised exanthematous pustulosis (AGEP) — red, pustular rash with fever
- Anaphylaxis — severe, rapid-onset allergic reaction
- Lupus-like syndrome — joint swelling, fatigue, and skin rash
- Agranulocytosis — dangerous reduction in white blood cells
- Dizziness, headache, tremor, vertigo, hyperreflexia
- Confusion, disorientation, hallucinations
- Nausea, vomiting, loss of appetite, dry mouth, abdominal pain, constipation
- Difficulty urinating, kidney damage
- Hyperglycaemia (elevated blood sugar), metabolic acidosis, pellagra
- Vasculitis (inflammation of blood vessels)
- Various forms of anaemia, thrombocytopenia (low platelet count)
- Allergic pneumonitis (lung inflammation)
- Arthritis (joint inflammation)
- Optic neuritis (damage to the optic nerve affecting vision)
Liver Monitoring
Because hepatotoxicity is one of the most serious adverse effects of isoniazid, regular monitoring of liver function is essential. The risk of hepatitis increases with age: approximately 0.3% of patients under 20 years are affected, rising to 1.2% at ages 35–49, and 2.3% in patients over 50. Other risk factors include daily alcohol consumption, pre-existing liver disease, concurrent use of hepatotoxic drugs, and chronic viral hepatitis (hepatitis B or C).
Baseline liver function tests (ALT, AST, bilirubin) should be obtained before starting treatment. Monthly monitoring is recommended for patients with risk factors. All patients should be educated about the symptoms of hepatotoxicity and instructed to stop the medication and contact their doctor immediately if symptoms develop.
Preventing Peripheral Neuropathy
Peripheral neuropathy is caused by isoniazid interfering with pyridoxine (vitamin B6) metabolism. The risk is highest in patients who are slow acetylators, malnourished, pregnant, diabetic, HIV-positive, or have chronic kidney disease. Pyridoxine supplementation (typically 10–25 mg daily, up to 50 mg in high-risk patients) is recommended for all patients taking isoniazid to prevent this side effect.
Reporting Side Effects
Reporting suspected adverse reactions after the medicine has been authorised is important. It allows continuous monitoring of the benefit-risk balance of the medicine. Healthcare professionals and patients are encouraged to report any suspected side effects to their national pharmacovigilance authority.
How Should You Store Tibinide?
- Keep out of sight and reach of children at all times.
- Store at room temperature (below 25°C / 77°F) unless otherwise specified on the packaging.
- Protect from moisture and direct sunlight.
- Do not use this medicine after the expiry date stated on the packaging. The expiry date refers to the last day of that month.
- Do not dispose of medicines via wastewater or household waste. Ask your pharmacist how to dispose of medicines you no longer use. These measures help protect the environment.
Packaging: Tibinide is supplied as white, round, flat tablets with a score line, in a plastic container of 100 tablets.
What Does Tibinide Contain?
| Component | Type | Function |
|---|---|---|
| Isoniazid 300 mg | Active substance | Antitubercular bactericidal agent |
| Microcrystalline cellulose | Excipient | Binder and filler |
| Stearic acid | Excipient | Lubricant |
| Talc | Excipient | Glidant |
| Silicon dioxide | Excipient | Flow agent |
Appearance: White, round, flat tablet with a score line. The score line allows the tablet to be divided into equal halves if needed.
Frequently Asked Questions About Tibinide
Tibinide contains isoniazid, a bactericidal antibiotic used specifically to treat and prevent tuberculosis (TB). It is most commonly used as part of a multi-drug regimen alongside other antitubercular medications such as rifampicin, pyrazinamide, and ethambutol. It can also be used alone for latent TB infection prophylaxis in individuals at high risk of developing active TB.
The most common side effects include peripheral neuropathy (numbness, tingling, or burning sensation in hands and feet) and elevated liver enzymes. Peripheral neuropathy risk can be reduced by taking pyridoxine (vitamin B6) supplements alongside Tibinide. Less common side effects include nausea, vomiting, loss of appetite, and hepatitis (liver inflammation).
No. Alcohol consumption should be strictly avoided during Tibinide treatment. Alcohol reduces the effectiveness of isoniazid and significantly increases the risk of liver damage (hepatotoxicity). The combination of isoniazid and alcohol can lead to serious, potentially fatal liver injury. If you have concerns about alcohol use during treatment, discuss them with your doctor.
Treatment duration depends on the indication. For active tuberculosis, isoniazid is typically part of a 6-month multi-drug regimen (2 months intensive phase with 4 drugs, followed by 4 months continuation phase with 2 drugs). For latent TB infection prophylaxis, isoniazid monotherapy is usually given for 6 to 9 months. Always complete the full prescribed course, even if you start feeling better, to prevent drug-resistant TB.
Foods high in tyramine should be avoided or limited during Tibinide treatment, as they may cause flushing, palpitations, irregular heartbeat, and elevated blood pressure. Tyramine-rich foods include aged cheeses, cured meats, fermented foods, soy sauce, red wine, and certain types of beer. Reactions typically occur within 30 minutes to 2 hours and resolve within 2–4 hours. Your doctor can provide more specific dietary advice.
Early signs of liver damage include yellowing of the skin or whites of the eyes (jaundice), dark-coloured urine, pale stools, itching, abdominal tenderness, nausea, loss of appetite, and unusual tiredness or weakness. If you experience any of these symptoms, stop taking Tibinide and contact your doctor immediately. Regular liver function monitoring is recommended throughout the course of treatment.
References
This article is based on the following international medical guidelines and peer-reviewed sources:
- World Health Organization (WHO). WHO consolidated guidelines on tuberculosis. Module 4: treatment – drug-susceptible tuberculosis treatment. Geneva: WHO; 2022. Available from: who.int
- World Health Organization (WHO). WHO Model List of Essential Medicines – 23rd list. Geneva: WHO; 2023.
- American Thoracic Society (ATS), Centers for Disease Control and Prevention (CDC), Infectious Diseases Society of America (IDSA). Treatment of Drug-Susceptible Tuberculosis. Clinical Infectious Diseases. 2016;63(7):e147–e195. doi:10.1093/cid/ciw376
- Nahid P, Dorman SE, Alipanah N, et al. Official American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America Clinical Practice Guideline: Treatment of Drug-Susceptible Tuberculosis. Clinical Infectious Diseases. 2016;63(7):e147–e195.
- European Medicines Agency (EMA). Summary of Product Characteristics: Isoniazid. Available from: ema.europa.eu
- British National Formulary (BNF). Isoniazid: Drug Monograph. National Institute for Health and Care Excellence (NICE). 2024.
- Saukkonen JJ, Cohn DL, Jasmer RM, et al. An official ATS statement: hepatotoxicity of antituberculosis therapy. American Journal of Respiratory and Critical Care Medicine. 2006;174(8):935–952. doi:10.1164/rccm.200510-1666ST
- Sterling TR, Njie G, Zenner D, et al. Guidelines for the Treatment of Latent Tuberculosis Infection: Recommendations from the National Tuberculosis Controllers Association and CDC, 2020. MMWR Recomm Rep. 2020;69(1):1–11.
Editorial Team
iMedic Medical Editorial Team — Specialists in Infectious Disease and Clinical Pharmacology. Our editorial team consists of licensed physicians with expertise in tuberculosis treatment and antimicrobial therapy.
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