There are some important things to know about pill splitting...
Basically it is safe to split any pill that is scored (has a break line usually to split the pill in halves, sometimes quarters).
Many pills are unsafe to split. These include
Time-Release Pills controlled-release (CR), sustained-release (SR) extended-release (XR) etc. These are pills are formulated so the drug is released slowly, so should never be crushed or chewed. They can only be split if there is a score line.
Enteric Coated Pills (EC) are formulated so that the tablets do not dissolve in acidic environments (such as the stomach) but further down in the intestines. This is particularly useful for drugs that irritate the stomach or for drugs that are destroyed by acid. Spitting these pills also splits the enteric coating.
Some pills are difficult to split accurately (they may be hard or crumbly) and this can cause problems in drugs where a precise dose is required.
It is a good idea to always check with your doctor or pharmacist first, and definitely check first if the pill contains more than one drug.
Atacand is unscored, but is also a simple round uncoated tablet. Theoretically this pill is safe to split. Because it is unscored, the most reliable way to do this is with a pill splitter which is available from your pharmacy.
Hope this helps
JJ