What adverse effect should be of immediate concern when administering didanosine?

When administering didanosine, peripheral neuropathy is the adverse effect that should be of immediate concern. This condition arises due to the drug's mechanism of action as a nucleoside analogue, which can lead to mitochondrial toxicity. This toxicity specifically impacts sensory neurons, resulting in symptoms like tingling, burning, or pain in the extremities. The onset of peripheral neuropathy may indicate that nerve damage is occurring, which can become a significant and debilitating health issue if not addressed promptly.

Monitoring for symptoms of peripheral neuropathy is crucial during treatment, as early intervention can help manage the side effects effectively. Other adverse effects such as excoriation, headache, and taste alteration may occur, but they are generally less severe than the potential for neuropathic complications. Thus, health care providers need to prioritize recognizing and managing peripheral neuropathy in patients receiving didanosine to prevent long-term damage.