Opposition lawmaker Alfonso Marquina announced Gruseny Antonio Calderon's death on Twitter, calling him "another victim of the dictatorship".
He was shot at during a protest in the central city of Barquisimeto on Tuesday.
Five people, including a 13-year-old boy have been killed since April 6 in clashes with riot police during a wave of protests against Maduro.
A fifth person died Thursday after being shot during protests against the Venezuelan government, officials said, as tension mounted in a political crisis driven by food shortages.
A 32-year-old man died from a gunshot wound suffered during clashes on Tuesday night in the northwestern town of Cabudare, a spokesman for the public prosecution service who asked not to be named told AFP.
Marquina blamed that killing on so-called "colectivos", armed supporters of the government who the opposition says commit violence during demonstrations.
"If they think they will scare us that way they are wrong. I'm going to stay in the streets until we get rid of this government", 21-year-old graphic designer Rolisber Aguirre said as he marched in the rain toward the center of the city.
Military police dispersed demonstrators.
Another group of around 1,000 people was targeted by police with tear gas and rubber bullets as they marched from the east of the city toward a highway leading downtown. "At peace", said protesting stay-at-home mother Aura Cuaita, 33.
Eurasia Group analyst Risa Grais-Targow said this month's protests look more unsafe for the government than similar efforts the opposition has mounted in past years.
The next major organized rallies called by opposition leaders are set for Wednesday next week.
The demonstrations are expected to be the next big showdown in an increasingly fraught crisis that has raised global concerns about Venezuela's stability.
Those moves have raised global condemnation including from the United States and the European Union.
About two weeks ago Venezuela's Supreme Court, which is filled with Maduro loyalists, backed down from its bid to nullify the opposition-dominated national assembly.
"It is absolutely vital that Venezuelans have the right to. elect their representatives in free and fair elections in accordance with the Venezuelan Constitution and consistent with worldwide instruments" said department spokesman Mark Toner.
While demonstrations are often held in middle-class neighborhoods, this most recent wave of unrest for the first time has sparked protests in the slums that have historically been bastions of support for the socialist revolution launched almost two decades ago by late President Hugo Chavez. Maduro says the economic crisis is the result of what he calls a US -backed capitalist conspiracy.