Poor medication compliance and concordance
Dysphagia can affect people of any age and has many root causes, but the problems it causes are the same. Patients with dysphagia have difficulty swallowing solid dose medication - thus they may often miss out on much-needed medicine. Overall some 45% of prescription medicines are not taken as directed with some 20% of medicines never being taken at all (Parry 2005).
In a recent pilot study conducted in community pharmacies across the UK where patients over the age of 65 were asked if they had problems swallowing their medication (Greener & Ferguson 2005):
- 62% had experienced difficulty in swallowing solid dose medication at some time
- 58% had crushed tablets or opened capsules to aid administration of their medication
- 68% said that they would not tell their doctor or pharmacist if they were unable to swallow their tablets
Equally, older patients who are at home and who are on medication may well have experienced difficulties with medication compliance. It is an all too frequent event that when an older patient is admitted to hospital or to a residential or nursing home they are accompanied by a carrier bag full of the last two years medication that for one reason or another has not been taken. "Repeat" medication may have been ordered religiously on a monthly basis however this is no guarantee that these medicines are taken (Greenwall, 2003).
When faced with the pain and discomfort of dysphagia, people often feel their only alternative is to crush tablets or open capsules and mix the contents in food or drink in order to receive their prescribed medicine.
A recent survey found (Preston & Morris 2005):
- 9% crushed tablets or opened capsules
- 8% put medicine in food or drink
- 5% chewed or sucked medication
Such routes of administration occur in over 80% of nursing homes on a weekly basis (Wright, 2002).
Changing the physical form can render a medicine 'unlicensed', making it ineffective or indeed harmful.
For patients where PEG, PEJ or nasogastric tubes have been fitted to facilitate enteral feeding, some special considerations must be taken into account when administering medication via these feeding tubes (Wright, 2002a).
Opening or crushing sustained, modified or controlled release medicines can radically alter pharmacokinetic and pharmacodynamic profiles. This often results in poor efficacy and/or adverse drug reactions (ADRs). There are certain formulations that should not be opened or crushed prior to administration (Greenwall, 2003).
For example, crushing a controlled release tablet causes the patient to receive the full 12 or 24-hour dose over a five to ten-minute period. This results in an initial overdose followed by a subsequent period without medication (Greenwall, 2003).
The crushing, opening or breaking of medicines that have carcinogenic properties (antineoplastics) may not only alter the delivery mechanism, but can lead to unwanted airborne release of particles, thus exposing the administrator to the dangers or cytotoxic activity. An example is Tamoxifen, which is routinely prescribed in breast cancer management (Wright, 2002).
The view of the Royal Pharmaceutical Society of Great Britain on crushing tablets is clear.
"If a formulation is tampered with then the product will be unlicensed. Pharmacists must consider and advise on the potential for distortion of bioavailability profile of the medicine"
The pharmacological effects associated with tablet crushing are exacerbated in the older patient as pharmacokinetics and pharmcodynamics alters with age. In addition several classes of drugs are known to cause an increase in adverse events in the older population due to the changes in the way drugs are handled in the body with age (Greenwall, 2003). Crushing tablets or opening capsules which are not designed to do so could compound these problems.