Medical aids believe the cost of drugs might be unsustainable as the demand for specialised medicine is escalating rapidly, the Cape Times reported on Wednesday.
Discovery Health said the increase in the cost of biologics was well above the general health care inflation rate.
Biologics, used to treat conditions like cancer and multiple sclerosis, are produced using live organisms, some extracted from animals or humans.
Between 1990 and 2010, the number of biotech drugs in South Africa increased from 10 to 210.
According to the report, Discovery Health increased its spend on these specialised drugs by 28.5 percent, well in excess of the 7.5 percent increase in the cost of claims.
It estimated that biologics would account for almost half of total chronic medication spend by 2016, but only 10 percent of people requiring chronic treatment would be able to afford them.