Glasgow City Council has sent letters to those affected informing them their care will be withdrawn for two days this week as about 8,000 workers walk out in an equal pay row.
It states: “The strike action is definitely taking place and unfortunately we have been unable to secure sufficient homecare staff to provide the cover we expected to.”
The letter asks recipients to make alternative arrangements with family, carers or friends if possible, apologises for the disruption and warns there will be no response to calls or emails during the strike tomorrow and Wednesday.
The family of one woman who received the letter said they fear lives will be put at risk as people may not be able to access medication.
Amy Coid, 90, is recently out of hospital and normally receives four care visits a day as she is blind in one eye and suffers from slight confusion, so is given meals and help to dress and get to bed.
Her medication is kept in her house in a padlocked box to which only her carers have the combination.
Her family are trying to get the code for this so they can give her the 14 tablets a day she needs but are concerned for others who will be left without care.
A relative said: “It looks like lives of many old people will be put at risk as they will not receive their medication.
“We are fortunate and will be able to make two 30-mile round trips each day to give her meds in morning and night.
“But how will confused elderly people with no relatives, neighbours or friends cope? Some will be on meds without which they might become seriously ill or worse.
“Some might not even understand the letter or not be able to do anything about it.”
He added: “I wonder how many lives may be at risk as a result and the council seems to be washing their hands of the potential deadly consequences for these vulnerable people who live alone.”
The council said the way the union had approached the strike was “hugely disappointing”.
Rhea Wolfson, GMB Scotland organiser, said its members would never do anything to cause harm to homecare clients.
“Glasgow City Council management... has misrepresented the offer our members have made to keep services running for our most vulnerable clients.”