Glossary

Cmin or Ctrough – lowest concentration of a drug just before the next dose.

What happens when you take a drug?

cotrimoxazole is combination two antibiotics (trimethoprim and sulfamethoxazole). Tradenames include Septrin and Bactrim.

Abbreviations for this combination include SXT, TMP-SMX, TMP-SMZ or TMP-sulfa.

Cotrimoxazole is commonly used in HIV care as a prophylaxis against PCP and toxoplasmosis. Everyone with a CD4 count that is less than 200 cells/mm³ need to also take cotrimoxazole until their CD4 count becomes higher.

Different guidelines recommend continuing with cotrimoxazole at different CD4 counts, depending on which country you live in. Sometimes this is at 100, 200, 350 or sometimes higher.

After being on effective ART for 3 to 6 months, cotrimoxazole can be stopped after the CD4 count increases to above 100 cells/mm³. This is only if they have never had PCP. Anyone who has previously had PCP, it is recommended to continue until the CD4 count is above 200 cells/mm³. This is based on EACS guidelines (v11.1, October 2022).

In countries with high risk of malaria or severe bacterial infections, prophylaxis should continue, irrespective of CD4 count on ART. There are also different recommendations for children and in other specific circumstances. (WHO consolidated guidelines, 2021)

See PCP and toxoplasmosis sections of the training manual.

diabetes – when the body either does not produce enough insulin (a hormone that helps the body turn sugar into energy) or is not responding to insulin (insulin resistance). There are two main types of diabetes and they have different mechanisms and treatments.

Type-1 is mainly reported in children but can also occur in adults and is linked to genetic risks.

Type-2 is mainly reported in adults (but increasingly in children) and is more commonly related to lifestyle factors including diet, exercise, weight/BMI. Some medications can increase the risk of Type-2 diabetes.

Diabetes can also be a side effect, including from some early HIV drugs, and this is sometimes referred to as a third type. This is because it was primarily caused as a side effect, rather than being driven by either lifestyle factors or genetics.

Other commonly-used drugs that can affect glucose regulation include corticosteroids and some drugs to reduce high blood pressure, or lipids.

CD4% – percentage of total lymphocytes (white blood cells) that are CD4 cells.

The CD4% is generally more stable than the CD4 count. For example, if you ever get a CD4 count that is much lower than you expect, first see whether the CD4% has changed too,

If the CD4% is still roughly the same then the low CD4 count is unlikely to show a real change.

DEXA – a non-invasive scan that can measure the percentage of different body areas (whole body, trunk, right leg etc) that are muscle or fat. DEXA scans cannot determine if this is central fat (visceral adipose tissue, VAT) or sub-cutaneous fat (under the skin).

DEXA scan also can measure bone density and is used to monitor risk of osteopenia and osteoporosis.