Valve cartridge for at least one sanitary fitting with a changeable function

A valve cartridge for at least one sanitary fitting, comprising:

• a cartridge housing;
• a valve stem that is rotatable about an axis of rotation relative to the cartridge housing;
• a handle for rotating the valve stem;
• a passage disk with a first passage and a second passage;
• a control disk rotatable with the valve stem for controlling a liquid flow through the first passage or the second passage of the passage disk;
• and
• a handle adapter connectable to the valve stem for setting a first rotational orientation of the valve stem to the handle in a first position and connectable to the valve stem for setting a second rotational orientation of the valve stem to the handle in a second position so that the control of the flow of liquid through the first passage or the second passage is changed via the control disk,
• wherein the handle adapter is non-rotatably fixed to the valve stem, such that during all rotational movement of the handle, the valve stem and the handle adapter rotate together.