"I felt drowsy … and then felt a little dizziness, I have rested and now feel 100%," Maduro said on Sunday, as broadcast on Twitter.
Maduro and his wife Cilia Flores got their first shots of Sputnik V on Saturday.
Last month, Venezuela received the first 100,000 doses of Russia’s Sputnik V vaccine.
Russia reached a deal with Venezuela in December on the supply of 10 million doses of Sputnik V, the world’s first registered vaccine against COVID-19.
Sputnik V is now the world's second-most imported COVID-19 vaccine after AstraZeneca'a, and Pfizer and Moderna come the third and the fourth, respectively. It has been registered under the emergency use authorization procedure and is now approved for use in 46 countries globally with a total population of over 1.2 billion people.
Interim results from Sputnik's Phase 3 clinical trials, as published in authoritative peer-reviewed medical journal The Lancet, established its efficacy at 91.6 percent.