What is Latent T.B.?
A condition where the person has the tubercular bacteria in his body, however there are no symptom. The individual looks normal on examination, no cough, fever, loss of weight etc.
The person may give a positive skin test, a positive blood test (quantiferon test), but the chest X ray is normal.
Is Latent T.B. Contagious?
You cannot pass the infection to someone else if you have latent T.B. The only risk is that you may develop the disease yourself if your immune power weakens at some point of time.
Debate about treating latent Tuberculosis
There remains a controversy about treating latent T.B. This is because even after full treatment, there remains a chance of re activation of the mycobacterium when opportunity comes.
The side effects of the drugs are disastrous and the benefits still remain unsure.
Latent T.B. Patients at a Risk for Developing the Disease
Only a few latent T.B. cases would progress to become the disease. These include:
- Those who are is close touch with T.B. patients
- If you are poor, homeles or undernourished
- Those visiting a country where T.B. is prevalent
- An HIV patient
- All alcohol users or intravenous drug abusers
- Elderly population
- If you are a person with weakened immunity
Role of INH in Latent Tuberculosis
IHN may be given in cases of latent tuberculosis. Whether to give or not is assessed by the physician. This would depend upon what are the chances that your T.B. would get activated or progress to become an active disease.
If given, the dose is 5mg/kg body weight to be taken daily. The dose must not exceed 300mg. It is given for 9 months.
There is a 6 month regimen also. However, the 9 month regimen is more efficacious.
How to Take INH?
It is taken on an empty stomach, that is, either one hour before a meal or two hours after a meal. The dose is decided on the basis of your age, gender and body weight.
Common Side Effects
In addition to its useful effects in the body, this drug may give you certain unwanted effects. These effects have to be managed while you are under treatment.
Your doctor or your health care professional would help you in this regard. If you are getting any undesirable effect that’s unbearable, report to your doctor immediately. The drug may need to be stopped immediately.
Related to Liver
Since the drug is metabolized in the liver before excretion, this organ is affected by it. You may have a darker urine while you are on INH. Your eye or skin color may be dark and body fatigue may be felt.
There may be a reduction in diet and feeling of nausea or even vomiting at times.
Related to Brain
INH adversely effects the nervous system. It is common for patients to feel clumsy or not alert. They may be confused.
This side effect usually tapers off with time, as the body gets habituated with the drug. However, sometime, these effects may progress, showing further brain damage.
The patient may show mental changes like depression of varying degrees or even seizures (convulsions). In such cases, the drug may have to be withdrawn.
Nerves are affected. Patient on INH may report a tingling sensation, which patient usually report as a metallic sensation in the peripheries, including feet and hands. Sometimes, the peripheries may pain or give a burning feel.
Blurring of vision is reported by some people on INH treatment. Rarely, the optic nerve, supplying the eye, may get affected. Optic neuritis has been reported in some. This is a serious side effect and the drug may need to be stopped to protect eye damage.
Sometimes, Pyridoxine (vitamin B6) is co administered with INH to prevent eye damage. Pyridoxine has a strong protective role and largely weakens the damaging effects.
Tiredness, particularly during the initial phase of treatment, may be due to anemia. This occurs because INH affects the blood cells. There may be sore throat or even fever. This occurs due to a slight reduction in the number of blood cells fighting infections in our body.
Hypersensitivity reaction are not uncommon with INH. In a mild form, which is common, this may occur in the form of a rash.