A new report has raised concerns that Australians are missing out on access to 18 important breakthrough medicines due to delays and challenges within the Pharmaceutical Benefits Scheme.

The medicines include treatments for serious conditions such as cancer, migraines, schizophrenia, multiple sclerosis and other chronic diseases.

Health experts warn some patients are facing limited treatment options, while some innovative medicines available overseas are not reaching Australian patients.

The report says pricing negotiations, regulatory delays and decisions by pharmaceutical companies are contributing to the problem.

The Federal Government says it is working to balance faster access to new treatments with keeping medicines affordable for Australians.

The debate has renewed calls for reforms to ensure Australians can access life-changing medicines sooner.