The following is a list of possible side-effects that may occur in medicines that contain Isoniazid. This is not a comprehensive list. These side-effects are possible, but do not always occur. Some of the side-effects may be rare but serious. Consult your doctor if you observe any of the following side-effects, especially if they do not go away.
Isoniazid may also cause side-effects not listed here.
If you 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.
Before using Isoniazid, inform your doctor about your current list of medications, over the counter products (e.g. vitamins, herbal supplements, etc.), allergies, pre-existing diseases, and current health conditions (e.g. pregnancy, upcoming surgery, etc.). Some health conditions may make you more susceptible to the side-effects of the drug. Take as directed by your doctor or follow the direction printed on the product insert. Dosage is based on your condition. Tell your doctor if your condition persists or worsens. Important counseling points are listed below.
Do not double the dose to make up for the missed dose
Have age above 35 years
Pregnant, planning to become pregnant or breastfeeding
Symptoms like unusual tiredness, weakness, feeling of discomfort, loss of appetite, urge to vomit or vomiting
Interactions with Isoniazid
If you use other drugs or over the counter products at the same time, the effects of Isoniazid may change. This may increase your risk for side-effects or cause your drug not to work properly. Tell your doctor about all the drugs, vitamins, and herbal supplements you are using, so that you doctor can help you prevent or manage drug interactions. Isoniazid may interact with the following drugs and products:
Please consult with your doctor for case-specific recommendations.
Is Isoniazid safe while breastfeeding?
Please discuss the risks and benefits with your doctor.
Can Isoniazid be used for phthisis and tuberculosis?
Yes, phthisis and tuberculosis are among the most common reported uses for Isoniazid. Please do not use Isoniazid for phthisis and tuberculosis without consulting first with your doctor. Click here and view survey results to find out what other patients report as common uses for Isoniazid.
Is it safe to drive or operate heavy machinery when using this product?
If you experience drowsiness, dizziness, hypotension or a headache as side-effects when using Isoniazid medicine then it may not be safe to drive a vehicle or operate heavy machinery. One should not drive a vehicle if using the medicine makes you drowsy, dizzy or lowers your blood-pressure extensively. Pharmacists also advise patients not to drink alcohol with medicines as alcohol intensifies drowsiness side-effects. Please check for these effects on your body when using Isoniazid. Always consult with your doctor for recommendations specific to your body and health conditions.
Is this medicine or product addictive or habit forming?
Most medicines don't come with a potential for addiction or abuse. Usually, the government's categorizes medicines that can be addictive as controlled substances. Examples include schedule H or X in India and schedule II-V in the US. Please consult the product package to make sure that the medicine does not belong to such special categorizations of medicines. Lastly, do not self-medicate and increase your body's dependence to medicines without the advice of a doctor.
Can i stop using this product immediately or do I have to slowly wean off the use?
Some medicines need to be tapered or cannot be stopped immediately because of rebound effects. Please consult with your doctor for recommendations specific to your body, health and other medications that you may be using.
Other important Information on Isoniazid
Missing a dose
In case you miss a dose, use it as soon as you notice. If it is close to the time of your next dose, skip the missed dose and resume your dosing schedule. Do not use extra dose to make up for a missed dose. If you are regularly missing doses, consider setting an alarm or asking a family member to remind you. Please consult your doctor to discuss changes in your dosing schedule or a new schedule to make up for missed doses, if you have missed too many doses recently.
Overdosage of Isoniazid
Do not use more than prescribed dose. Taking more medication will not improve your symptoms; rather they may cause poisoning or serious side-effects. If you suspect that you or anyone else who may have overdosed of Isoniazid, please go to the emergency department of the closest hospital or nursing home. Bring a medicine box, container, or label with you to help doctors with necessary information.
Do not give your medicines to other people even if you know that they have the same condition or it seems that they may have similar conditions. This may lead to overdosage.
Please consult your physician or pharmacist or product package for more information.
Storage of Isoniazid
Store medicines at room temperature, away from heat and direct light. Do not freeze medicines unless required by package insert. Keep medicines away from children and pets.
Do not flush medications down the toilet or pour them into drainage unless instructed to do so. Medication discarded in this manner may contaminate the environment. Please consult your pharmacist or doctor for more details on how to safely discard Isoniazid.
Taking a single dose of expired Isoniazid is unlikely to produce an adverse event. However, please discuss with your primary health provider or pharmacist for proper advice or if you feel unwell or sick. Expired drug may become ineffective in treating your prescribed conditions. To be on the safe side, it is important not to use expired drugs. If you have a chronic illness that requires taking medicine constantly such as heart condition, seizures, and life-threatening allergies, you are much safer keeping in touch with your primary health care provider so that you can have a fresh supply of unexpired medications.
Please consult your physician or pharmacist or refer to the product package.
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APA Style Citation
Isoniazid - Product - TabletWise.com. (n.d.). Retrieved July 23, 2021, from https://www.tabletwise.com/medicine/isoniazid