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 primarily prescribed for the treatment of tuberculosis (TB). It is a key component of the standard anti-tuberculosis drug regimen. Isoniazid works by inhibiting the growth of the bacteria that cause tuberculosis, thereby helping to eliminate the infection.

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: Your healthcare provider will prescribe a specific dosage based on your age, weight, overall health, and the severity of your condition. Take the medication exactly as prescribed.
• Administration: Isoniazid is typically taken orally as a tablet or liquid. It is usually taken once a day, but in some cases, your healthcare provider may recommend a different schedule.
• Timing: Isoniazid is often taken on an empty stomach, at least one hour before or two hours after meals. However, your healthcare provider may provide specific instructions, so follow them closely.
• Consistency: Try to take isoniazid at the same time each day to maintain a consistent level of the medication in your body.
• Avoid certain substances: Do not consume alcohol while taking isoniazid, as it can increase the risk of liver problems. Be cautious with foods high in tyramine, as they may interact with isoniazid and cause an increase in blood pressure.
• Vitamin B6 supplementation: Your healthcare provider may recommend vitamin B6 (pyridoxine) supplementation to prevent or manage peripheral neuropathy, a potential side effect of isoniazid.
• Full course: Complete the entire course of treatment, even if you start feeling better before it is finished. Stopping the medication prematurely may result in incomplete treatment and increase the risk of developing drug-resistant tuberculosis.
• Regular monitoring: Your healthcare provider may order periodic blood tests to monitor liver function and ensure the medication is not causing adverse effects.
• Follow-up appointments: Attend all follow-up appointments with your healthcare provider to monitor your progress and discuss any concerns or side effects.
• Missed dose: If you forget a dose, take it as soon as you remember. If it’s almost time for your next dose, skip the missed one and continue with your regular schedule. Do not double up on doses.

It’s crucial to communicate openly with your healthcare provider about any concerns, side effects, or changes in your health. They can provide personalized guidance and address any questions you may have about your treatment with isoniazid.

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?

When taking isoniazid, individuals should be aware of and follow specific precautions to ensure the safe and effective use of the medication. Some important precautions include:

• Liver Function Monitoring: Isoniazid can potentially cause liver damage. Regular monitoring of liver function through blood tests is essential during treatment.
• Peripheral Neuropathy: Long-term use of isoniazid may lead to peripheral neuropathy. Patients may experience numbness, tingling, or weakness in the hands and feet. Pyridoxine (vitamin B6) supplementation is often recommended to mitigate this risk.
• Drug Interactions: Isoniazid can interact with other medications, potentially affecting their efficacy or increasing the risk of side effects. Inform your healthcare provider about all medications, supplements, and herbal products you are taking.
• Alcohol Consumption: Alcohol can increase the risk of liver damage when combined with isoniazid. It’s generally advisable to limit or avoid alcohol during treatment.
• Pregnancy and Breastfeeding: Consult with a healthcare provider if you are pregnant, planning to become pregnant, or breastfeeding, as the safety of isoniazid during pregnancy and lactation may need to be carefully considered.
• Slow Acetylators: Some individuals metabolize isoniazid more slowly, leading to higher blood levels and an increased risk of side effects. Genetic factors may influence this, and dosage adjustments may be necessary.

Always follow your healthcare provider’s instructions and inform them of any pre-existing medical conditions or medications you are taking to ensure safe and effective use of isoniazid.

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 people may experience side effects that are not listed. If you are prescribed isoniazid, your healthcare provider will monitor you for potential side effects. Common side effects may include:

• Nausea and vomiting: Isoniazid can cause nausea and vomiting, especially when taken on an empty stomach. Taking the medication with food or a snack may help alleviate this.
• Peripheral neuropathy: This is a potential side effect that involves damage to the nerves in the extremities, leading to symptoms such as tingling, numbness, or weakness. Vitamin B6 (pyridoxine) supplementation may be recommended to prevent or manage this side effect.
• Liver problems: Isoniazid can affect liver function. Your healthcare provider may monitor your liver with periodic blood tests. If you experience symptoms of liver problems, such as yellowing of the skin or eyes (jaundice), dark urine, or persistent nausea, you should contact your healthcare provider immediately.
• Rash: Some people may develop a skin rash as a side effect of isoniazid. If you notice any rash, especially if it is severe or accompanied by other symptoms, inform your healthcare provider.
• Flu-like symptoms: Isoniazid may cause flu-like symptoms, including fever, chills, and muscle aches.
• Dizziness: Some individuals may experience dizziness or lightheadedness while taking isoniazid.
• Joint pain: Joint pain is a less common side effect, but it can occur in some individuals.

It’s important to report any unusual or severe side effects to your healthcare provider promptly. Additionally, if you experience symptoms of an allergic reaction, such as difficulty breathing, swelling of the face or throat, or severe rash, seek medical attention immediately.

Remember that the benefits of taking isoniazid to treat tuberculosis generally outweigh the potential risks of side effects. If you have concerns about the medication or its side effects, discuss them with your healthcare provider. They can provide guidance, adjust your treatment plan if needed, or explore alternative options.

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.