Tuberculosis treatment: the regimen and adherence

Tuberculosis is treated with several drugs together over months because the organism divides slowly and any population of it already carries a few naturally resistant bacilli, so a single drug -- or a combination the patient has reduced to a single drug by taking it unevenly -- kills what is susceptible and leaves what is resistant to multiply into a disease that is harder, longer and more toxic to cure; the standard course for drug-susceptible disease is an intensive phase of several drugs followed by a continuation phase of fewer, taken daily and preferably as fixed-dose combinations so that the drugs cannot be pulled apart from one another, and across that course the nurse is doing three things at once -- protecting the patient from what the drugs do, proving the treatment is working, and keeping the patient on it; each first-line drug carries a harm that is taught before it appears and watched for afterwards: isoniazid, rifampicin and pyrazinamide are all hepatotoxic, so loss of appetite, nausea, vomiting, discomfort under the right ribs, dark urine or yellowing of the eyes or skin means the drugs are held and liver function checked rather than the patient reassured that tablets upset the stomach, isoniazid also causes a peripheral neuropathy that pyridoxine is given alongside it to prevent, ethambutol injures the optic nerve so any blurring, any loss of sharpness and any change in the way colours look is reported the day it is noticed, and rifampicin turns urine, sweat and tears orange-red, which is harmless but is told to the patient in advance so that it does not stop the treatment and so that soft contact lenses are not permanently stained, while the same drug speeds the body's clearance of other medicines, hormonal contraception among them, so everything else the patient takes is reviewed against it; whether the treatment is working is judged on the sputum converting, the symptoms settling and the weight returning rather than on how the patient feels in the early weeks, and the full course is finished because the patient feels well long before the organism is dead and a sputum that has turned negative means the patient has stopped being infectious, not that the disease has been cured; and adherence is supported rather than policed -- the guidance now speaks of treatment support instead of directly observed treatment, given inside people-centred care and without coercion -- so the patient is taught what each drug is for and what to report, and is offered the support their own circumstances call for, whether that is treatment given close to home rather than at a facility, observation by a trained health worker or lay provider rather than by a relative, video-supported treatment, reminders or a digital medicine monitor, material help with food or transport, or counselling, while an interruption is reported and the next step taken on advice rather than made up quietly at the end, because interruption is how resistance is manufactured.