WARNING

Isoniazid is a medication commonly used to treat tuberculosis (TB). While it is generally effective, there are potential risks and side effects associated with its use. Here’s a brief overview of some of the risks of taking Isoniazid:

• Hepatotoxicity: Isoniazid can cause liver damage in some individuals. Regular monitoring of liver function is often recommended during treatment.
• Peripheral Neuropathy: Long-term use of Isoniazid, particularly in individuals with poor nutrition or certain pre-existing conditions, may lead to peripheral neuropathy, which is damage to the nerves in the extremities.
• Allergic Reactions: Some people may experience allergic reactions to Isoniazid, which can range from mild skin rashes to severe reactions like Stevens-Johnson syndrome.
• Drug Interactions: Isoniazid can interact with other medications, potentially affecting their efficacy or increasing the risk of side effects. It’s important to inform your healthcare provider about all medications you are taking.
• Metabolic Effects: Isoniazid may lead to changes in blood sugar levels, which could be of concern in individuals with diabetes.
• Psychiatric Effects: Rarely, Isoniazid has been associated with psychiatric side effects, such as psychosis and depression.
• Peripheral Arthralgia: Some individuals may experience joint pain as a side effect of Isoniazid.

It’s crucial to take Isoniazid under the supervision of a healthcare professional who can monitor for these potential risks and adjust the treatment plan if necessary. Patients should report any unusual symptoms or side effects promptly to their healthcare provider. The benefits of treating tuberculosis with Isoniazid often outweigh the risks, especially when the medication is prescribed and monitored appropriately.

Why is this medication prescribed?

Isoniazid is a medication primarily prescribed for the treatment and prevention of tuberculosis (TB). TB is a bacterial infection caused by Mycobacterium tuberculosis, and isoniazid is one of the first-line drugs used in the standard TB treatment regimen.

Here are some key points regarding the use of isoniazid:

• Treatment of Tuberculosis: Isoniazid is often used in combination with other anti-TB medications to effectively treat active tuberculosis infections.
• Prophylaxis (Prevention): Isoniazid is also used as a preventive measure for individuals who have been exposed to TB but have not yet developed an active infection. This is known as latent TB infection, and isoniazid can help prevent the development of active TB disease in such cases.
• Combination Therapy: In TB treatment, isoniazid is commonly combined with other drugs such as rifampin, pyrazinamide, and ethambutol, depending on the specific treatment regimen prescribed by a healthcare professional.

How should this medicine be used?

Isoniazid is usually prescribed to treat tuberculosis (TB). It’s important to follow your healthcare provider’s instructions carefully. Here are general guidelines for the use of isoniazid:

• Dosage: The dosage of isoniazid can vary based on factors such as age, weight, and the specific condition being treated. It is important to follow the prescribed dosage provided by a healthcare professional.
• Administration: Isoniazid is typically taken orally, usually on an empty stomach. It can be taken with or without food, but taking it on an empty stomach may help improve absorption.
• Duration of Treatment: The duration of isoniazid treatment depends on the specific condition being treated. For active TB, the treatment duration is usually several months. For latent TB infection prophylaxis, the duration may be shorter.
• Adherence: It is crucial to complete the entire course of medication as prescribed, even if symptoms improve before the medication is finished. Failure to complete the full course of treatment can lead to the development of drug-resistant strains of TB.
• Monitoring: While on isoniazid, individuals may be monitored for any potential side effects or adverse reactions. Liver function tests may be performed periodically, as isoniazid can affect the liver in some cases.

It’s important to note that isoniazid may interact with other medications, and individuals should inform their healthcare provider of all medications, supplements, and medical conditions before starting isoniazid or any other new medication. As with any medication, individuals should consult their healthcare provider for personalized advice and guidance.

Other uses for this medicine

While isoniazid (INH) is primarily used for the treatment of tuberculosis (TB), it may also be employed for other medical conditions in certain situations. Some of these include:

• Latent Tuberculosis Infection (LTBI): Isoniazid is commonly prescribed as a preventive measure for individuals with latent tuberculosis infection, especially those at high risk of developing active TB.
• Prophylaxis in Close Contacts: It might be given as a preventive measure to individuals who have been in close contact with someone diagnosed with active tuberculosis to reduce the risk of infection.
• Certain Atypical Mycobacterial Infections: Isoniazid may be used in combination with other antibiotics for the treatment of specific atypical mycobacterial infections.

What special precautions should I follow?

Here are some general precautions and considerations for using isoniazid:

• Liver Function Monitoring: Isoniazid can sometimes cause liver damage. Your healthcare provider may monitor your liver function through blood tests during the course of treatment.
• Peripheral Neuropathy: Long-term use of isoniazid may lead to peripheral neuropathy, a condition affecting the nerves. Your doctor may monitor for symptoms such as numbness, tingling, or weakness in the extremities.
• Vitamin B6 (Pyridoxine) Supplementation: Isoniazid use can lead to a deficiency of vitamin B6. Your healthcare provider may recommend vitamin B6 supplements to counter this effect.
• Drug Interactions: Inform your healthcare provider about all medications, supplements, and herbal products you are taking to check for potential interactions with isoniazid.
• Pregnancy and Breastfeeding: Consult with your healthcare provider if you are pregnant, planning to become pregnant, or breastfeeding, as isoniazid may have implications for these situations.

Always follow your healthcare provider’s advice and take the medication as prescribed. If you experience any unusual or severe side effects, contact your healthcare provider promptly.

What special dietary instructions should I follow?

• Food interactions: Isoniazid should be taken on an empty stomach, at least one hour before or two hours after meals, unless otherwise directed by your healthcare provider.
• Tyramine-containing foods: While there are no specific dietary restrictions with isoniazid, it’s advisable to avoid foods high in tyramine (aged cheeses, cured meats, certain fermented foods) as interactions with isoniazid may cause an increase in blood pressure.
• Vitamin B6-rich foods: If your healthcare provider recommends vitamin B6 supplementation, consider incorporating foods rich in B6 into your diet, such as poultry, fish, potatoes, and fortified cereals.

What should I do if I forget a dose?

If you forget to take a dose of Isoniazid, follow these general guidelines:

• Take it as soon as you remember: If you miss a dose, take it as soon as you remember. However, if it’s almost time for your next scheduled dose, skip the missed one and continue with your regular dosing schedule.
• Don’t double up: Do not take a double dose to make up for a missed one. Taking extra medication may increase the risk of side effects.
• Inform your healthcare provider: If you frequently forget doses or have concerns about your medication schedule, talk to your healthcare provider. They can provide guidance and may adjust your treatment plan if necessary.

What side effects can this medication cause?

Isoniazid, like any medication, can cause side effects. It’s important to note that not everyone will experience these side effects, and some side effects may be temporary or mild. Common side effects of isoniazid include:

• Gastrointestinal Distress:
  • Nausea
  • Vomiting
  • Upset stomach
• Peripheral Neuropathy:
  • Tingling or numbness in the hands or feet
  • Weakness
• Hepatotoxicity (Liver Damage):
  • Elevated liver enzymes
  • Hepatitis (inflammation of the liver)
• Allergic Reactions:
  • Rash
  • Itching
  • Fever
  • Joint pain
• Pyridoxine (Vitamin B6) Deficiency: Isoniazid can lead to a deficiency in vitamin B6, resulting in neurological symptoms.
• Psychiatric Effects: Rarely, isoniazid may cause psychiatric effects such as confusion or psychosis.
• Hypersensitivity Reactions: Severe allergic reactions, including anaphylaxis, are rare but possible.
• Optic Neuritis: Inflammation of the optic nerve may occur, causing vision changes.
• Blood Disorders: Isoniazid can affect blood cell counts, leading to conditions like agranulocytosis or thrombocytopenia.
• Metabolic Effects: Changes in blood sugar levels, particularly in individuals with diabetes.

It’s important to seek medical attention if you experience severe or persistent side effects. Additionally, let your healthcare provider know about any pre-existing conditions you may have, as well as other medications or supplements you are taking, as these factors can influence the risk of side effects or interactions.

In some cases, the benefits of treating tuberculosis with isoniazid outweigh the potential risks of side effects. Your healthcare provider will monitor you during treatment and may adjust the treatment plan if needed. If you are prescribed isoniazid, it’s crucial to take the medication as directed and to attend follow-up appointments with your healthcare provider.

What should I know about storage and disposal of this medication?

Storage and Disposal:

• Storage: Keep isoniazid in its original container, tightly closed, and at room temperature. Avoid exposure to excessive heat, moisture, and light. Follow any specific storage instructions provided by your pharmacist or healthcare provider.
• Disposal: Dispose of unused or expired medication in a safe and environmentally friendly way. Do not flush medications down the toilet unless instructed to do so. Ask your pharmacist about local guidelines for medication disposal.

In case of emergency/overdose

If you suspect an overdose or experience severe symptoms, seek emergency medical attention immediately. Overdose symptoms may include:

• Seizures
• Severe dizziness or lightheadedness
• Unsteadiness or difficulty walking
• Confusion
• Slurred speech

What other information should I know?

• Follow your healthcare provider’s instructions: Take isoniazid exactly as prescribed. Do not alter the dosage or stop taking the medication without consulting your healthcare provider.
• Regular monitoring: Your healthcare provider may order regular blood tests to monitor liver function and ensure the medication is not causing adverse effects.
• Complete the course: Finish the entire course of isoniazid as prescribed, even if you start feeling better before completing it. Skipping doses or stopping early may result in incomplete treatment and increase the risk of developing drug-resistant tuberculosis.
• Avoid alcohol and certain foods: Limit or avoid alcohol consumption while taking isoniazid, as it may increase the risk of liver problems. Be cautious with foods containing tyramine, as they may interact with isoniazid and cause an increase in blood pressure.
• Inform healthcare providers: Inform all healthcare providers involved in your care that you are taking isoniazid. This includes dentists, surgeons, and other specialists.
• Drug interactions: Inform your healthcare provider about all other medications, supplements, and herbal products you are taking to avoid potential drug interactions.
• Allergic reactions: If you develop signs of an allergic reaction, such as rash, itching, swelling, severe dizziness, or difficulty breathing, seek medical attention promptly.

Always consult your healthcare provider or pharmacist if you have specific questions or concerns about your medication. They can provide personalized guidance based on your health status and medical history.