We know that they can affect the function of normal cells, and this can result in complications such as the peripheral neuropathy Other drugs such as AZT interfere with bone marrow and cause anemia. We don't understand why protease inhibitors increase cholesterol and produce diabetes. A certain class of these inhibitors is known to interfere with mitochondria, the energy producing agent in cells, and produce metabolic abnormalities like lactic acidosis, which in some cases can be life threatening. With these drugs, the life threatening form is rare but recently there has been some suggestion that many of the relatively mild side effects such as fatigue and nausea may be a result of a low-grade lactic acidosis. This is an area in which we know very little.
Lactic acidosis is the accumulation of lactic acid within the blood.
And lactic acid is an abnormal product of the body's metabolism. This is what occurs when the body is unable to produce enough energy. When people aren't getting enough oxygen, they may develop lactic acidosis because of an alternative pathway to producing energy. These drugs by poisoning mitochondria might have a similar effect, and thus disrupt the body's normal acid-base balance. Certainly, the lipid abnormalities can be managed with lipid limiting agents, as is used with other people with high cholesterol, and diabetes can be managed with oral agents.