Ivan Clarkson

Ivan Clarkson Photo: Supplied

The family of a missing 80-year-old man say he has been without critical heart medication since vanishing on the way to a doctor’s appointment on Wednesday afternoon.

Ivan Clarkson left his home in Clyde, in Melbourne’s outer south-east, for a short drive to a medical clinic in nearby Cranbourne.

But he never arrived, and has been missing for more than 24 hours.

Detective Senior Constable Andrew Rodwell said Mr Clarkson's family feared for his health and safety because he did not have his daily heart medication with him.

Mr Clarkson missed his 2pm medical appointment and was last spotted on CCTV at a petrol station in the area about 1.30pm.

He was driving a white 2011 Lexus station wagon with registration YDB 917.

‘‘He has never gone missing before – it’s completely out of character,’’ Senior Constable Rodwell said.

‘‘And he doesn’t have dementia or alzheimer’s.’’

He said Mr Clarkson’s disappearance was not being treated as suspicious, and no one had used his bank cards.

‘‘But all up, it is quite strange’’.

Anyone who sees him is urged to call police.