Final answer:
The Lidoderm patch is an effective topical analgesic for relieving postherpetic neuralgia in adults.
Step-by-step explanation:
The topical analgesic that is effective for relieving postherpetic neuralgia in adults is the Lidoderm patch.
Postherpetic neuralgia is a chronic pain condition that occurs after a shingles infection. Lidoderm patch contains lidocaine, which is a local anesthetic that helps numb the area and provide pain relief. It is applied directly to the affected area and can be effective in relieving the pain associated with postherpetic neuralgia.