Crushing tablets or opening capsules: many uncertainties, some established dangers.

For patients who have difficulty swallowing, a common solution is to crush tablets or open capsules. What are the consequences of this practice? We reviewed the main evidence available using the standard Prescrire methodology. The clinical consequences for the patient of crushing tablets or opening capsules can be serious: alteration of the drug's absorption can result in sometimes fatal overdose, or conversely underdosing, rendering the treatment ineffective. When it disrupts a drug's sustained-release properties, the active ingredient is no longer released and absorbed gradually, resulting in overdose. When a gastro-resistant layer is destroyed by crushing, underdosing is likely. The active ingredient released may degrade on contact with light, moisture or the food with which it is mixed for administration. The person who crushes the tablets or opens the capsules is exposed to drug particles, which may be carcinogenic, teratogenic or fetotoxic. They are sometimes allergenic. In practice, there are many drugs that should never be crushed or opened. Before crushing a tablet or opening a capsule, it is better to consider and research the impact it will have on the drug's effects. It is sometimes preferable to use a different dosage form, or a different active ingredient.