The terms "preventive therapy" and "chemoprophylaxis" have been used for decades and are preferred in the UK because it involves giving medication to people who have no active disease and are currently well, the reason for treatment is primarily to prevent people from becoming unwell. The term "latent tuberculosis treatment" is preferred in the US because the medication does not actually prevent infection: it prevents an existing silent infection from becoming active. The feeling in the US is that the term "treatment of LTBI" promotes wider implementation by convincing people that they are receiving treatment for disease. There are no convincing reasons to prefer one term over the other. It is essential that assessment to rule out active TB is carried out before treatment for LTBI is started. To give LTBI treatment to someone with active TB is a serious error: the TB will not be adequately treated and there is a risk of developing drug-resistant strains of TB. There are several treatment regimens available:

9H—Isoniazid for 9 months is the gold standard and is 93% effective. 6H—Isoniazid for 6 months might be adopted by a local TB program based on cost-effectiveness and patient compliance. This is the regimen currently recommended in the UK for routine use. The US guidance exclude this regimen from use in children or persons with radiographic evidence of prior tuberculosis (old fibrotic lesions). (69% effective)
6 to 9H2—A twice-weekly regimen for the above two treatment regimens is an alternative if administered under Directly observed therapy (DOT).
Omacetaxine mepesuccinate (INN, trade names Synribo ), formerly named as homoharringtonine or HHT, is a pharmaceutical drug substance that is indicated for treatment of chronic myeloid leukemia (CML). HHT is a natural plant alkaloid derived from Cephalotaxus fortunei. HHT and related compound esters of cephalotaxine were described first in 1970, and were the subject of intensive research efforts by Chinese investigators to clarify their role as anticancer and antileukemic agents from the 1970s until the present. It was approved by the US FDA in October 2012 for the treatment of adult patients with CML with resistance and/or intolerance to two or more tyrosine kinase inhibitors (TKIs). Medical uses
Omacetaxine/homoharringtonine is indicated for use as a treatment for patients with chronic myeloid leukaemia who are resistant or intolerant of tyrosine kinase inhibitors.In June 2009, results of a long-term open label Phase II study were published, which investigated the use of omacetaxine infusions in CML patients. After twelve months of treatment, about one third of patients showed a cytogenetic response. A study in patients who had failed imatinib and who had the drug resistant T315I mutation achieved cytogenetic response in 28% of patients and hematologic response in 80% of patients, according to preliminary data.Phase I studies including a small number of patients have shown benefit in treating myelodysplastic syndrome (MDS, 25 patients) and acute myelogenous leukaemia (AML, 76 patients). Patients with solid tumors did not benefit from omacetaxine. Adverse effects
By frequency:
Very common (>10% frequency):

Common (1–10% frequency):

Seizures
Haemorrhage† Myelosuppression, including: thrombocytopenia, anaemia, neutropenia and lymphopenia, in descending order of frequency.