When in Rome do as the Romans do — but not in the Pacific, where ex-deputy prime minister Michael McCormack has come off second best after an encounter with kava, the locals’ favourite tipple.

The Nationals frontbencher was taken to a medical clinic in Pohnpei in Micronesia after downing a ceremonial shell of local kava, known as “sakau”, on Wednesday.

He revealed he drank five bowls of kava in Vanuatu the previous day.

His reaction to kava, which has a narcotic and sedative effect, meant he could not continue to Palau with other Australian MPs in the delegation led by Foreign Minister Penny Wong.

Michael McCormack’s smile has returned after his unintended kava binge. Photo: AAP

Mr McCormack was treated for dehydration and had a long sleep at the Australian ambassador’s house.

He returned to Australia on Friday, telling reporters he went “cross-eyed” and threw up after finishing the sakau, which he said was stronger than the Vanuatu kava he consumed the day before.

“I drank down the whole lot in one hit,” the ABC reported him saying.

“It just hit me. Overwhelming. It’s like a sedative – like a drunken feeling.”

Mr McCormack said he was trying to be respectful but in future he would just take a sip at kava-drinking rituals “as Penny sensibly did”.

-with AAP