Cotrimoxazole consists of two antimicrobial agents: trimethoprim and sulfamethoxazole.  It is also known as CTX or TMP-SMX.

 

One single-strength tablet of cotrimoxazole is trimethoprim 80 mg and sulfamethoxazole 400 mg.

 

One double-strength tablet of cotrimoxazole is trimethoprim 160 mg and sulfamethoxazole 800 mg. 

 

Cotrimoxazole contains a sulfa drug, so use caution or avoid in patients with sulfa allergies.  It is possible to desensitize people with mild to moderate sulfa allergies in order to safely give them cotrimoxazole, especially in places where alternative drugs are not available.  You can see the WHO desensitization protocol here: www.who.int/hiv/pub/guidelines/WHO%20CTX.pdf

 

Regarding its cost-effectiveness, a recent study by Ryan, et. al. reported that “Cotrimoxazole prophylaxis was associated with incremental cost-effectiveness ratios (ICERs) of US$72 per life-year saved, US$94 per QALY saved and US$53 per DALY averted, i.e. substantially less than a cost-effectiveness threshold of US$1019 per outcome (gross domestic product per capita, Zambia 2006). ICERs of US$5 or less per outcome demonstrate that cotrimoxazole prophylaxis is even more cost-effective at the local healthcare level. The intervention remained cost-effective in all sensitivity analyses including routine haematological and CD4% monitoring, varying starting age, AIDS status, cotrimoxazole formulation, efficacy duration and discount rates.”