Anti-Diarrheal Drugs

Determine the Cause

There are many potential causes of diarrhea, and several may be occurring at once. It's important to identify all the causes and treat them appropriately. These may include infections in the gut (e.g., parasitic, bacterial, fungal, and viral infections), side effects of medications, lactose intolerance, diet and/or HIV itself.

If a person has blood in the stool (i.e., feces) and/or has a fever, there may be an infection causing the diarrhea. A physician should be seen right away. Physicians will take a stool sample, test for the possible infections, and recommend appropriate treatment. Some common infections include Cryptosporidium, Microsporidium, Mycobacterium avium complex (MAC), cytomegalovirus (CMV), Giardia, and Salmonella. When diarrhea is caused by a known infection, physicians may prescribe the appropriate antibiotic, antifungal, antiparasitic, or antiviral medication. It is important to remember that an infection may exist even without bloody stool or a fever.

Many antiviral drugs, such as nelfinavir and ddI, list diarrhea as a common side effect. A number of antibiotics like clarithromycin, azithromycin, and ciprofloxacin can also cause diarrhea. Treating the symptoms may help in such cases.

Lactose intolerance can also result in diarrhea. Many people with HIV cannot properly digest lactose, a sugar found in milk, cheese, and other dairy products. Some medications come in capsules that contain lactose, such as the current formulation of saquinavir. If lactose intolerance is suspected, try eliminating dairy products to see if this improves the condition. It is often possible to correct the problem by using over-the-counter products designed to help digest lactose.

A person's diet may inadvertently also contribute to the problem. High levels of fat in the diet are particularly difficult for the body to deal with during times of intestinal distress. In general, a low fat diet is easier to digest and puts less strain on the digestive system and liver.

Finally, chronic diarrhea may simply be a direct result of HIV infection of the lymphatic tissues lining the intestinal tract. This is particularly difficult to combat since the best solution is potent antiviral therapy, yet diarrhea and poor absorption directly interfere with the uptake of these drugs. In this case, controlling the symptoms of diarrhea may help correct the underlying cause by simply forcing the body to do a better job absorbing and retaining antiviral therapies. If no other causes can be identified, people should assess their antiviral regimen, as failing therapies may add to increased HIV infection in the gut.

Unfortunately, it is often difficult to determine the cause of diarrhea. Sometimes, repeated diagnostic tests must be run before a clear cause is identified. When diarrhea is short-term and goes away on its own, it may not matter much. But when it is continuing and chronic, it is very important to keep searching for the cause, however unpleasant it may be.