Latent Tuberculosis Infection(Positive PPD) and INH Treatment PATIENT EDUCATION SERIES

What is TB and how is it contracted? In order to distinguish between the active and latent form of the disease, you will need to have a Tuberculosis (TB) is a disease caused by a germ chest x-ray. Your health care provider may also called Mycobacterium tuberculosis that is spread take a medical history and perform a brief physi- from person to person through air. TB usually cal exam. If you have a normal chest x-ray and do not have evidence of active disease in your lungs or affects the lungs but can affect other parts of the elsewhere, then you have what is known as latent body, such as the brain, the kidneys or the spine. tuberculosis infection (LTBI). Persons with active When a person with infectious TB coughs or sneez- TB can spread the disease to others. Persons with es, droplets containing Mycobacterium tuberculosis latent TB do not spread the disease to others and are expelled into the air. If another person inhales can be easily treated to prevent the development of air containing these droplets, he or she may become active TB. infected. However not everyone infected with TB becomes sick. Two TB conditions exist: latent TB What else can cause a positive TB skin (LTBI) and active TB disease. test?

What is a TB skin test? A recent BCG (Bacille-Calmette-Guerin) vaccina- tion may sometimes cause a positive TB skin test. The TB skin test is used to screen for tuberculosis BCG is a vaccine given in many countries where TB by identifying people who have the tuberculosis is endemic to prevent TB infection. However, ef- (TB) organism in their bodies. A positive TB skin ficacy of BCG ranges only from 56-80% and the pro- test means that you are infected with the bacteria, tective effect of BCG lasts only a few years. BCG is Mycobacterium tuberculosis, and it is present in not routinely given in the United States. The Cen- your body. TB bacteria live in the bodies of most ter for Disease Control generally advises that those infected people in an inactive form and do not cause with positive TB skin tests receive treatment for any symptoms of disease; this condition is referred LTBI regardless of BCG history. In some cases, a to as Latent TB Infection (LTBI). TB blood test (IGRA) is advised for those who have received BCG in the past to help with treatment de- cisions. Like a positive TB skin test, a positive TB Overall, 10% of people with LTBI will have the blood test with no signs of active disease indicates bacteria become active and become very sick, over latent TB infection, for which treatment is advised. their lifetime. The risk for developing active disease Your provider will discuss whether this is indicated is greatest within the first year after developing a for you. positive TB skin test. It is also greater for those individuals who use intravenous drugs or who have What are the symptoms of active TB? diseases such as HIV, silicosis,diabetes, leukemia, weakened immune systems, kidney disease, and Some people don’t have symptoms. Others may some other chronic diseases. Also, as people get develop: older the tuberculosis germ can become active, start • cough, sometimes with blood tinged mucous to grow, and cause illness. • fever • night sweats Without treatment for LTBI, 10% of people with a • unintentional weight loss positive TB skin test will develop active tubercu- • unusual decreased appetite losis at some time. Not only will those individu- • shortness of breath als who develop active TB become very sick and • body sweats at night require treatment with multiple, sometimes toxic drugs for months, but they can easily spread TB to Treatment for Latent TB infection others. This is why it is so important to identify and treat latent TB before it becomes active. Treatment The good news is that there are effective medica- for 9 months can stop the conversion of latent to ac- tions available. tive TB in over 90% of people who complete the full course of medication. The most commonly prescribed medication is iso- niazid (INH). It is given as a pill and is usually

BROWN UNIVERSITY HEALTH SERVICES | www.brown.edu/health | 401.863-3953 taken once daily for nine months. The Ameri- • abdominal discomfort/pain, especially in the can Thoracic Society and the Centers for Disease right upper abdomen Control recommend nine months as the optimal • unexplained fever, greater than 3 days duration duration of treatment. Again, the protective effect • itchy skin may be as high as 90% if all the medication is taken • nausea properly. • vomiting • unexplained lack of appetite At Health Services, once you start on 9 months of • unusual decrease in appetite or weight loss INH treatment, you will generally be required to • cola-colored urine have follow-up appointments with an RN (working • pale clay-colored stool • yellow skin/eyes together with your provider)at least every 2 months • joint aches to make sure all is going well. You will receive re- • easy bleeding/bruisability minders for INH visits. If ANY of the above symptoms develop, stop your INH (Isoniazid) Facts INH and call your RN/provider at Health Services as soon as possible. It is important to seek care Serious toxicity due to INH is uncommon. Stomach early if any hepatitis symptoms might be develop- upset such as bloating or nausea can occur with ing. Your RN/provider will want to check your blood initial doses, but usually disappears after several liver enzymes and examine you as soon as possible. doses. Drug-induced hepatitis (inflammation of the liver) occurs in about 0.1% of younger individuals. • INH should be taken daily on an empty stom- Higher rates of hepatitis occur in older populations, ach. If stomach upset occurs, INH can be taken those with some chronic medical conditions, risk with a small snack. Antacids should not be factors for hepatitis such as underlying liver dis- taken along with INH as they interfere with its ease, or those who use alcohol during INH treat- absorption. If antacids are needed, they should ment. Pregnant or postpartum women are also at be taken at least one hour after the dose of INH. greater risk. Discuss any medical conditions you have with your provider prior to starting INH. • If a dose is missed, tell your RN or health care The side effect of liver inflammation is usually provider at your next follow-up appointment. Do not take the extra dose as no more than one reversible when the INH is stopped. Your provider dose of INH should be taken in a 24 hour period. will order a baseline blood test at the start of INH If you have missed 2 weeks or more of daily treatment to make sure that your liver function is INH, call Health Services as soon as possible for normal. Occasionally repeat blood tests may be nec- an appointment. essary, depending on your medical history, during the course of treatment. • Drug interactions can occur between INH and other medications, herbal supplements and It is recommended that you abstain from alco- over the counter medicines. Your provider will hol completely during your INH treatment check initially to make sure that any medica- because alcohol can increase the risk of hepa- tion you take regularly does not interact with titis. INH, but be sure to discuss any new medica- tions (prescribed by another provider outside Rarely, in less than 0.2% of people, INH may cause Health Service for example)or OTCs/supple- irritation of the nerves ( neuropathy) in your ment with your RN or provider. hands and feet. This may lead to symptoms of numbness or tingling and are more likely in people Once you have been treated for LTBI, there is no with underlying chronic conditions such as diabe- need to ever have another TB test, as once the TB tes, kidney disease, and with frequent alcohol use. skin test is positive, it is positive for life. When you Your provider may prescribe Vitamin B6 which complete a course of treatment with INH for LTBI, Health Services will provide you with a card/letter usually helps to prevent this problem. which documents your past history of a positive TB skin test or postive TB blood test, and your treat- Symptoms to watch for while on INH: ment. This documentation can be presented in the future to any agency or medical provider who may • Unusual fatigue or malaise greater than 3 days request TB screening, as an explanation for why duration you do not need a TB screen again. • Rash 2/14

BROWN UNIVERSITY HEALTH SERVICES | www.brown.edu/health | 401.863-3953