A powerful neurotransmitter-blocking medicine is apparently what landed Pyotr Verzilov in critical condition at the toxicology wing of Moscow’s Bakhrushin City Clinical Hospital on September 11. Verzilov’s partner says he started losing his vision, speech, and mobility before he was rushed to the emergency room.

Citing his doctors, the activist’s friends told Meduza that physicians believe he either overdosed on or was poisoned by anticholinergic drugs, which are used to treat a variety of conditions, including dizziness, ulcers, insomnia, and asthma. Verzilov’s family told Meduza that they are “1,000-percent” certain that he didn’t willingly ingest any anticholinergic drugs.

Verzilov remains in critical condition, but his life is reportedly not in danger, and he is slowly recuperating. Relatives say he still isn’t speaking, and “reacts only with his eyes.”

A member of Pussy Riot and the publisher of the investigative news website Mediazona, which conducts often daring reporting on Russia's criminal justice system, Verzilov has been a prominent figure in Russia’s anti-Kremlin opposition movement since the late 2000s, when he performed in the controversial “Voina” artist-activist group alongside his then wife, Nadezhda Tolokonnikova.

How Verzilov ended up hospitalized ‘First it was his vision, then his speech, and then his legs’ Pussy Riot member Pyotr Verzilov is hospitalized in critical condition and friends fear he was poisoned