Crushing medication

Pharmacists often receive queries about crushing tablets or opening capsules, usually when liquid formulations are unavailable or costly as an unlicensed special. However, manipulating medicines carries important risks.

Crushing can alter drug absorption, although in many situations crushing tablets is unlikely to have any effect on the action of the medicine. Formulations that should never be crushed are:

• Modified-release preparations as the slow release mechanism will be destroyed allowing for the full dose to be release as a single dose (termed “dose dumping”). Patients should be changed to an immediate release formulation that may require more frequent dosing
• Gastro-resistant or enteric coated tablets which prevent the release of the drug in the stomach. Crushing could result in either stomach irritation or reduced efficacy (if acid unstable)
• Hormonal, steroidal, or cytotoxic medicines  due to the risk to patient or person administering the medication of skin sensitisation of inhalation of powder. Where crushing of these medicines is considered essential suitable measures must be put in place to protect the person crushing and administering the medicine.
• Medicines with a narrow therapeutic index (e.g., lithium, digoxin, warfarin). Crushing can affect the bioavailability and in drugs with a narrow therapeutic index a small change could cause dangerous under or over-dosing

Film-coated tablets can be crushed but this may be difficult and affect taste, adherence, and protection against moisture.

Practical Considerations when deciding to crush

• Stability – will the medicine react with air or moisture?
• Bioavailability changes - will the drug level be affected by crushing? Could this result in a risk of toxicity?
• Adherence - will crushing the tablet affect adherence as crushed tablets can be unpalatable?
• Loss of dose during crushing or mixing with water – only a small amount of liquid, if dispersing, should be used to ensure the whole dose is taken
• Risk of cross-contamination when crushing multiple tablets

Legal and  Ethical Implications

Crushing or opening capsules usually makes the medicine unlicensed. Liability is shared between prescriber, pharmacist, and the person administering the medicine. When offering advice on suitability for crushing:

• Assess the patient’s clinical need and patient safety risks
• Document decisions, alternatives considered, and obtain consent

Explore licensed alternatives first and ensure protective measures if manipulation is unavoidable.