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Isoniazid Solution for injection

It is used to prevent or to treat tuberculosis (TB).

Generic Name: isoniazid

Brand Names: Nydrazid

There is an FDA Alert for this drug. Click here to view it.

  • Severe and sometimes fatal hepatitis reported; hepatitis usually develops during the first 3 months of therapy but may develop after many months.
  • Risk of developing hepatitis is age related. Approximate case rates by age are: <1 per 1000 in individuals <20 years of age; 3 per 1000 in individuals 20–34 years of age; 12 per 1000 in individuals 35–49 years of age; 23 per 1000 in individuals 50–64 years of age; 8 per 1000 in individuals >65 years of age.
  • Risk of hepatitis is increased by daily consumption of alcohol, chronic liver disease, and use of illicit injection drugs.
  • There may be an increased risk of fatal hepatitis in women, particularly black and Hispanic women. Risk also may be increased during the postpartum period.
  • Precise data on fatality rate for isoniazid-related hepatitis not available. There were 8 deaths among 174 cases of hepatitis in a US Public Health Service Surveillance Study that included 13,838 individuals.
  • Monitor and interview patients at monthly intervals. In addition, determine AST and ALT concentrations at baseline and periodically (monthly or more frequently as needed) in individuals ≥35 years of age and in individuals at increased risk of hepatitis.
  • Increases in serum transaminase concentrations occur in 10–20% of patients; these increases usually occur during the first few months of therapy but can occur at any time. Enzyme concentrations usually return to pretreatment values despite continued isoniazid therapy, but progressive liver dysfunction occurs in some cases.
  • Consider discontinuing isoniazid if liver function abnormalities are >3–5 times ULN.
  • Liver function tests are not a substitute for monthly clinical evaluations or for prompt assessment of signs or symptoms of adverse reactions that may occur between regularly scheduled evaluations.
  • Patients should be advised to immediately report prodromal symptoms of hepatitis to their clinician. (See Advice to Patients.)
  • Discontinue immediately if symptoms or signs suggestive of hepatic damage are detected; continued isoniazid use has been reported to cause a more severe form of liver damage.
  • Patients who have signs or symptoms of isoniazid-associated hepatic damage should be treated using alternative antituberculosis agents. If use of isoniazid is considered necessary, the drug should be restarted only after symptoms and laboratory abnormalities have cleared. In this situation, isoniazid should be restarted in very small dosages and gradually increased; discontinue immediately if there is any indication of recurrent liver involvement.
  • Use of isoniazid for treatment of latent tuberculosis infection (LTBI) should be deferred in patients with acute hepatic disease.

What is this medicine?

ISONIAZID (eye soe NYE a zid) is used to prevent or to treat tuberculosis (TB).

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:
  • diabetes
  • HIV positive
  • if you frequently drink alcohol-containing beverages
  • kidney disease
  • liver disease
  • malnutrition
  • tingling of the fingers or toes, or other nerve disorder
  • an unusual or allergic reaction to isoniazid, other medicines, foods, dyes or preservatives
  • pregnant or trying to get pregnant
  • breast-feeding

How should I use this medicine?

This medicine is for injection into a muscle. It is usually given by a health care professional in a hospital or clinic setting.

If you get this medicine at home, you will be taught how to prepare and give this medicine. Use exactly as directed. Take your medicine at regular intervals. Do not take it more often than directed. Take all of your medicine as directed even if you think you are better. Do not skip doses or stop your medicine early. Skipping doses may make the TB resistant to this medicine and other medicines. Do not stop taking except on your doctor's advice.

It is important that you put your used needles and syringes in a special sharps container. Do not put them in a trash can. If you do not have a sharps container, call your pharmacist or healthcare provider to get one.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.

What if I miss a dose?

If you miss a dose, use it as soon as you can. If it is almost time for your next dose, use only that dose. Do not use double or extra doses.

What may interact with this medicine?

Do not take this medicine with any of the following medications:
  • entacapone
  • green tea
  • levodopa
  • MAOIs like Carbex, Eldepryl, Marplan, Nardil, and Parnate
  • procarbazine
  • ranolazine
  • tolcapone

This medicine may also interact with the following medications:

  • acetaminophen
  • alcohol
  • antacids
  • medicines for diabetes
  • medicines for fungal infections like ketoconazole and itraconazole
  • medicines for seizures like carbamazepine, phenobarbital, phenytoin, valproic acid
  • theophylline
  • zalcitabine

What should I watch for while using this medicine?

Visit your doctor or health care professional for regular check ups. You will need blood work done regularly.

You may need to take vitamin supplements while on this medicine. Talk to your doctor about the foods you eat and the vitamins you take.

Alcohol may interfere with the effect of this medicine. Avoid alcoholic drinks.

If you are diabetic check your blood sugar as directed. Also, you may get a false-positive result for sugar in your urine. Talk with your doctor.

What side effects may I notice from receiving this medicine?

Side effects that you should report to your doctor or health care professional as soon as possible:
  • allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
  • breathing problems
  • changes in vision or eye pain
  • dark urine
  • fever, sore throat
  • hallucination, loss of contact with reality
  • loss of appetite
  • memory problems
  • nausea, vomiting
  • pain, tingling, numbness in the hands or feet
  • redness, blistering, peeling or loosening of the skin, including inside the mouth
  • seizures
  • stomach pain
  • unusual bleeding or bruising
  • unusually weak or tired
  • yellowing of the eyes or skin

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):

  • breast enlargement or tenderness
  • diarrhea
  • headache
  • irritation at site where injected
  • upset stomach
  • trouble sleeping

Last Updated: May 05, 2009
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