"However, no studies have been conducted to confirm the safety of this practice. In fact, many in the medical community, including the American Medical Association , the American Pharmaceutical Association , and the American Society of Consultant Pharmacists , strongly oppose pill-splitting policies.
Risk of Dosing Errors
Pill splitting involves a number of risks. Those who promote the practice often omit how splitting medications negatively impacts patient safety by increasing dosing errors . Many pills cannot be split, and those that can be split do not necessarily guarantee the proper dose.
Tablets often break or crumble unevenly, and even tablets with scores (a small groove down the center) don't always split evenly - potentially leading to situations where patients either under- or over-dose on their medications.
Pills That Should Never Be Split
There are multiple types of medications that should never be split due to an increased potential for dosing errors. These include:
Capsules - These may contain a liquid, powder, or tiny pellets, which when cut open, cannot be divided equally. Time-released medicines - These may also be called long-acting, controlled-release, or extended-release medicines. Splitting one of these pills is dangerous since it would cause a patient to receive several hours worth of medication all at once. Enteric-coated medicines - These types of pills release medicine after it has passed through the stomach. Splitting these pills may release the medicine too soon and cause stomach irritation or reduce the drug's effectiveness. Transdermal patches - Some patches contain a liquid or gel inside, which if cut would either release the drug too quickly or reduce the amount of medication transmitted. Also, the patch may not stick to the skin as well if it has been cut. "
Defective Drug Information - Dangers of Splitting Medications