Monday, May 16, 2005
Isoniazid
Drug description
Isoniazid is used alone or with other drugs to treat tuberculosis (TB) and to prevent it in people who have had contact with tuberculosis bacteria, but shows no symptoms. It eliminates only active (growing) bacteria. Since the bacteria may exist in a resting (non-growing) state for long periods, therapy with isoniazid (and other antituberculosis drugs) must be continued for a long time (usually 6-12 months).
What special precautions should I follow?
Before taking isoniazid,
- tell your doctor and pharmacist if you are allergic to isoniazid or any other drugs.
- tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially acetaminophen (Tylenol), antacids, carbamazepine (Tegretol), disulfiram (Antabuse), ketoconazole (Nizoral), phenytoin (Dilantin), theophylline (Theobid, Theo-Dur), valproic acid (Depakene, Depakote), and vitamins.
- tell your doctor if you have or have ever had kidney disease; diabetes; tingling, burning, and pain in the fingers or toes (peripheral neuropathy); or human immunodeficiency virus (HIV).
tell your doctor if you are pregnant or plan to become pregnant. If you become pregnant while taking isoniazid, call your doctor. - be aware that you should not drink alcoholic beverages while taking this drug.
Side effects
Peripheral neuropathy is the most common side effect. Signs and symptoms of peripheral neuropathy are numbness, tingling, or an unusual sensation such as burning or prickling on the skin. Hepatitis is the most dangerous. Hepatitis is an inflammation of the liver. Signs and symptoms of hepatitis are yellow eyes and skin, nausea, vomiting, anorexia, dark urine, unusual tiredness, or weakness. Severe reactions may occur if you eat foods containing high concentrations of tyramine such as aged cheeses, avocados, bananas, beer, caffeinated beverages, chocolate, sausages, liver, overripe fruit, red wine, smoked or pickled fish, yeasts, and yogurt.
What special dietary instructions should I follow?
Isoniazid may cause an upset stomach. Take isoniazid with food or milk.
Dosage
Isoniazid comes in tablet, syrup and injectable forms. Isoniazid must be used cautiously if you have a history of liver damage or chronic alcoholism. While safety is not established, isoniazid has been used with ethambutol to treat TB in pregnant women without harm to the fetus. Dosage is 5-10 mg/kg/day (usually 300 mg) or 15 mg/kg 2-3 times per week. Take the drug on an empty stomach, at least 1-2 hours before meals or 2 hours after meals.
What should I do if I forget a dose?
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
How long it may take to work
Resolution of symptoms indicates treatment is effective. TB drugs may have to be taken for as long as 2 years.
What side effects can this medication cause?
Although side effects from isoniazid are not common, they can occur. Tell your doctor if any of these symptoms are severe or do not go away:
- diarrhea
- vision problems
If you experience any of the following symptoms, call your doctor immediately:
- eye pain
- numbness or tingling in the hands and feet
- skin rash
- fever
- swollen glands
- sore throat
- unusual bleeding or bruising
- stomach pains or tenderness
Managing side effects
Isoniazid must be taken with vitamin B6 to reduce the incidence of peripheral neuropathy. Take 40-50 mg of vitamin B6 per day. If GI irritation becomes a problem, drug may be administered with food, although food decreases absorption of isoniazid. Antacids may also be taken 1 hour before administration. If you are being treated by injection, you may experience discomfort at the injection site. Massage site after administration and rotate injection sites. Notify your doctor if any signs or symptoms of peripheral neuropathy or hepatitis occur. Changes in visual clarity, eye pain, or blurred vision should be reported. Avoid the foods listed above. These can cause redness or itching of the skin, hot feeling, rapid or pounding heartbeat, sweating, chills, cold clammy feeling, headache, or lightheadedness. Notify your doctor if any of these reactions occur.
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And so, the result is finally out on my TB status. i am tested positive for latent TB, but the x-ray shows no problem in my lungs. The Mantoux test on my left arm confirmed my high exposure to TB bacteria, giving rise to its 19mm diameter. Sad to say, i'm pescribed Isoniazid, an anti-TB drug to be consumed for the next 6 months to destroy the pathogens in my body. There're side effects involved, so i'm actually quite worried. i have never come close to thinking that i'll have to consume this sort of drug at such a young age, but i guess life is just so unpredictable.
Dont worry, friends. For the TB bacteria in my body are in the inactive state. i do hope they do not become full-blown, if i stick to consuming my medication diligently. Till then, 6 months later, during November, when i can just say 'bye bye' to the TB germs and to TB Control Unit over at Moulmein Road. i can hardly wait.
TB Control Unit shall be the next "favourite" haunt for latent-TB-infected NJCians. Or maybe just a selected few for 04s10. Sad.
