Murky Antidote

Murky antidotes are supposed to heal poisoning, but instead they slow the consumer. This effect lasts 2 turns or until the character is hasted. This item appears in Baldur's Gate, Baldur's Gate: Enhanced Edition and Baldur's Gate II.

In-game description
"As the name implies, this potion appears to neutralize any poison of which the imbiber is currently suffering the effects. The cleansing is instant and the potion may only be used once. Although the color seems strange somehow."