Videx

Didanosine

Chemical structure of Didanosine

Didanosine, also known by its brand name Videx, is an antiretroviral drug used in the treatment of HIV/AIDS. It is classified as a nucleoside reverse transcriptase inhibitor (NRTI), which works by inhibiting the action of reverse transcriptase, an enzyme crucial for the replication of HIV.

Mechanism of Action

Didanosine is a synthetic purine nucleoside analogue of deoxyadenosine. Once inside the body, it is converted to its active form, dideoxyadenosine triphosphate (ddATP). This active form competes with the natural substrate, deoxyadenosine triphosphate, for incorporation into the viral DNA by reverse transcriptase. The incorporation of ddATP into the viral DNA chain results in chain termination, thereby inhibiting viral replication.

Clinical Use

Didanosine is used in combination with other antiretroviral agents for the treatment of HIV infection. It is not recommended as monotherapy due to the rapid development of resistance. The drug is available in various formulations, including tablets and powder for oral solution.

Side Effects

Common side effects of didanosine include:

• Peripheral neuropathy
• Pancreatitis
• Diarrhea
• Nausea
• Rash

Serious side effects may include lactic acidosis and severe hepatomegaly with steatosis, which can be fatal.

Pharmacokinetics

Didanosine is rapidly absorbed after oral administration, but its bioavailability is reduced by the presence of food. It is therefore recommended to be taken on an empty stomach. The drug is primarily eliminated by the kidneys, and dose adjustments may be necessary in patients with renal impairment.

History

Didanosine was developed in the late 1980s and was one of the first antiretroviral drugs approved for the treatment of HIV. It was approved by the Food and Drug Administration (FDA) in 1991.

Related pages

• HIV/AIDS
• Antiretroviral drug
• Nucleoside reverse transcriptase inhibitor
• Zidovudine