Pharmaceutical experts have destroyed over 65 tonnes of expired medicine collected from various hospitals and drug stores.
The drugs were burned at Envirosafe Limited in Athi River's Export Processing Zone Authority in Mavoko on Thursday.
Pharmaceutical Society of Kenya president Paul Mwaniki said 70 per cent of the medicines were from public health facilities and the rest from outlets.
Representatives of the Kenya Pharmaceuticals Association, Pharmacy and Poisons Board, and individual pharmacists collected the medicine from last month.
Mwaniki said most of the drugs were seized at more than 20 county health facilities in Mombasa, Kwale, Kitui and Nairobi.
He said it is likely the counties they did not reach also have medicine that should be destroyed.
"We did not know there were lots of expired drugs in homes and county facilities. We suspect there is more than a metric tone of expired drugs in the country," he said.
"It concerns us that there could be more expired drugs that need to be destroyed as fast as possible."
Mwaniki noted county governments do not have policies and capacities for safe disposal of expired medicines.
"We will work with the Council of Governors to come up with effective policies," he said.
"For medicine to be destroyed, the Pharmacy and Poisons Board has to inspect and approve the firm that intends to effect the destruction."
Mwaniki said the confiscated drugs had been accumulated by the county facilities for more than seven years.
He said all dealers must be registered by the society to ensure they remain professional and ethical.
"Expired drugs are never recycled," Mwaniki said, adding the operation will be conducted across the country.
Association deputy secretary Betty Mulinge said it is costly for the private sector to confiscate and destroy expired medicine on its own.
She cautioned the public against keeping expired drugs in their homes and asked counties to follow procedures on donating medicine.