Nydrazid

(Generic versions may still be available.)

DRUG DESCRIPTION


WARNING: (isoniazid)

Severe and sometimes fatal hepatitis associated with isoniazid therapy has been reported and may occur or may develop even after many months of treatment. The risk of developing hepatitis is age related. Approximate case rates by age are: less than 1 per 1, 000 for persons under 20 years of age, 3 per 1,000 for persons in the 20-34 year age group, 12 per 1,000 for persons in the 35 -49 year age group, 23 per 1,000 for persons in the 50-64 year age group, and 8 per 1,000 for persons over 65 years of age The risk of hepatitis is increased with daily consumption of alcohol. Precise data to provide a fatality rate for isoniazid related hepatitis is not available; however, in a U. S. Public Health Service Surveillance Study involving 13,838 persons taking isoniazid, there were 8 deaths among 174 cases of hepatitis.

Therefore, patients given isoniazid should be carefull monitored and interviewed at monthly intervals. For persons 35 and older, in addition to monthly symptom reviews, hepatic enzymes (specifically, AST and ALT (formerly SGOT and SGPT, respectively)) should be measured prior to starting isoniazid therapy and periodically throughout treatment. Isoniazid-associated hepatitis usually occurs du ring the first three months of treatment. Usually, enzyme levels return to normal despite continuance of drug, but in some cases progressive liver dysfunction occurs. Other factors associated with an increased risk of hepatitis include daily use of alcohol, chronic liver disease and injection drug use. A recent report suggests an increased risk of fatal hepatitis associated with isoniazid among women, particularly black and Hispanic women. The risk may also be increased during the postpardum period. More careful monitoring should be considered in these groups, possibly including more frequent laboratory monitoring. If abnormalities of liver function exceed three to five times the upper limit of normal, discontinuation of isoniazid should be strongly considered. Liver function tests are not a substitute for a clinical evaluation at monthly intervals or for the prompt assessment of signs or symptoms of adverse reactions occurring between regularly scheduled evaluations Patients should be instructed to immediately report signs or symptoms consistent with liver damage or other adverse effects. These include any of the following: unexplained anorexia, nausea, vomiting, dark urine, icterus, rash persistent paresthesias of the hands and feet, persistent fatigue, weakness or fever of greater than 3 days duration and/or abdominal tenderness, especially right upper quadrant discomfort. If these symptoms appear or if signs suggestive of hepatic damage are detected, isoniazid should be discontinued promptly, since cont nued use of the drug in these cases has been reported to cause a more severe form of liver damage.

Patients with tuberculosis who have hepatitis attributed to isoniazid should be given appropriate treatment with alternative drugs. If isoniazid must be reinstituted, it should be reinstituted only after symptoms and laboratory abnormalities have cleared. The drug should be restarted in very small and gradually increasing doses and should be withdrawn immediately if there is any indication of recurrent liver involvement Preventive treatment should be deferred in persons with acute hepatic diseases.


Isoniazid is an antibacterial available as 100 mg or 300 mg tablets for oral administration.

Isoniazid is chemically known as isonicotinyl hydrazine or isonicotinic acid hydrazide.

Isoniazid is odorless, and occurs as a colorless or white crystalline powder or as white crystals. It is freely soluble in water, sparingly soluble in alcohol, and slightly soluble in chloroform and in ether. Isoniazid is slowly affected by exposure to air and light.

Inactive Ingredients: Anhydrous lactose, microcrystalline cellulose and stearic acid.

What are the precautions when taking isoniazid (Nydrazid)?

See also Warning section.

Before taking isoniazid, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: previous severe reaction from isoniazid (such as liver disease), liver disease, alcohol use, HIV infection, kidney disease, diabetes, numbness/tingling of arms/legs (peripheral neuropathy), recent childbirth.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Alcohol may...

Read All Potential Precautions of Nydrazid


Nydrazid Consumer (continued)

SIDE EFFECTS: See also Warning section.

Nausea/vomiting or stomach upset may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these unlikely but serious side effects occur: numbness/tingling of arms/legs, painful/swollen joints.

Tell your doctor immediately if any of these rare but serious side effects occur: change in the amount of urine, increased thirst/urination, vision changes, easy bruising/bleeding, signs of a new infection (such as fever, persistent sore throat), mental/mood changes (such as confusion, psychosis), seizures.

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: See also Warning section.

Before taking isoniazid, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: previous severe reaction from isoniazid (such as liver disease), liver disease, alcohol use, HIV infection, kidney disease, diabetes, numbness/tingling of arms/legs (peripheral neuropathy), recent childbirth.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Alcohol may increase the risk of liver disease. Avoid alcoholic beverages while using this medication.

This product may cause live bacterial vaccines (such as BCG vaccine) not to work as well. Therefore, do not have any immunizations/vaccinations while using this medication without the consent of your doctor.

Liquid forms of this medication may contain sugar. Caution is advised if you have diabetes or any other condition that requires you to limit/avoid sugar. Ask your doctor or pharmacist about using this product safely.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

This product passes into breast milk but is unlikely to harm a nursing infant. Consult your doctor before breast-feeding.



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