Orally taken tablets in different formulations continue to have a central role in the treatment of various psychiatric and medical conditions. In order to improve compliance, reduce the frequency of taking medications and minimize the peaks and troughs associated with certain immediate-release formulations, pharmaceutical companies have developed a number of novel methods of delivering oral solid dosage medications in the form of controlled-release (CR) formulations. Some CR formulations have been associated with pharmacobezoars and false-positive findings on certain physical investigations. Though CR drugs are commonly used in psychiatry, clinicians appear to have a limited understanding of how they are released for absorption once ingested. Some have insoluble parts that are excreted in faeces as 'ghost pills'. Due to lack of awareness of this phenomenon to both patients and the physicians, anxiety has ensued in some patients. Some clinicians have been puzzled or have been dismissive when faced with curious patients wanting to know more after they had observed tablet-like looking structures in faeces. We present two cases from our clinical setting and a few drawn from the World Wide Web to highlight the role of CR medications and their association with the ghost pill phenomenon. The mechanisms involved in drug release relevant to psychiatry medications are also briefly reviewed. The ghost pill phenomenon occurs with certain CR medications. This is a normal and expected outcome related to drug-release mechanisms of some of these products. It is inevitable that some patients will see what looks like tablets or capsules in faeces. Raising awareness of this phenomenon among clinicians would facilitate discussions and information sharing at the initial process of medication prescribing. Awareness among patients and carers would also help to allay anxiety.

Background: Slow release (SR) drug formulations associated with the passage of intact tablet like object in faeces sometimes known as the "ghost pill" have been in the market for many years. Anecdotal evidence suggests that few health care professionals are aware of this phenomenon. Our study aims were to find out what proportion of health care professionals was aware of the ghost pill phenomena and what drug formulations and specific drugs were associated with it. Methods: A survey was conducted among health care professionals at three hospital sights in the West Midlands, UK. The subjects included doctors, nursing staff, pharmacists, and other allied professionals involved in patient care. Results: A total of 321 health care professionals were included in the final analysis. Very few, 12.8% (41) have heard of the ghost pill phenomenon and a further 14 (4.4%) have come across of a patient who has experienced it. Only 13 (4%) correctly associated the phenomenon with SR drug formulations. Conclusion: Our survey has shown that the ghost pill phenomenon, a normal outcome of a novel way of delivering orally taken SR drugs, is not well-known among health care professionals. Lack of awareness of it has implications to trainers, medical and nonmedical prescribers and nursing staff working with patients who are taking these medications. Lack of awareness among health care staff, may result in relevant information not being shared with patients at the time of prescribing or when patients enquires of it.