Patient counselling Counselling of patients is important to optimise therapy, aid compliance and inform of any potential complications of therapy. Resistance Resistance may be defined as resistance of an infection to any one anti-tuberculosis agent. Multiple drug resistance usually applies when there is resistance to both isoniazid and rifampicin. Resistance patterns vary from country to country but are more prevalent in the US and developing countries. Streptomycin resistance is higher but is less likely to be used first-line in this country.
Poor compliance contributes much more than resistance to therapeutic failure.
Standard regimens may be used, even though resistance to one or more agents has been demonstrated as failure to respond tends to determine a change in therapy. Modification of the standard regimens is usual if isoniazid resistance is detected prior to or during chemotherapy. Multiple drug-resistant strains are treated initially with at least three drugs to which isolates are sensitive until a sputum smear negative status is obtained. A further continuation phase of at least nine months with two of these agents is recommended. Intermittent treatment is not usually used in multiple drug-resistant cases.