That’s Not What the Doctor Ordered; When PRN Medications are Regularly Administered

That’s Not What the Doctor Ordered; When PRN Medications are Regularly Administered

In a sample of patients from a forensic psychiatric hospital in Finland, pro re nata (PRN) medications were administered more frequently for both psychiatric and physical reasons in patients who were female, had more severe psychiatric symptoms, and functioned at a lower level. The prevalent use of PRN medications for physical reasons was not explained by patient characteristics. This is the bottom line of a recently published article in The International Journal of Forensic Mental Health. Below is a summary of the research and findings as well as a translation of this research into practice.

Featured Article | International Journal of Forensic Mental Health | 2020, Vol. 19, No. 4, 392-340

PRN Medication Events in a Forensic Psychiatric Hospital: A Document Analysis of the Prevalence and Reasons


Kirsi Hipp, University of Turku
Eila Repo-Tiihonen, Niuvanniemi Hospital; University of Eastern Finland; University of Helsinki
Lauri Kuosmanen, University of Eastern Finland
Jouko Katajisto, University of Turku
Mari Kangasniemi, University of Turku


The aim of this study was to describe and explain the prevalence and reasons for as needed medication (pro re nata, PRN) in a forensic psychiatric hospital. We reviewed the documents of 67 long-term inpatients (87% male) over the one-year study period and identified 8626 PRN events. Virtually all of the patients received PRN for physical reasons, just over half for psychiatric reasons, and just over one-third for insomnia. The number of PRN events per patient was unevenly distributed. The prevalence of PRN events for both psychiatric reasons (26%) and insomnia (14%) were associated with the female gender, more severe psychiatric symptoms, and lower daily functioning. Half of the patients did not receive PRN for psychiatric reasons. It is likely that the use of such medication was successfully mitigated with scheduled medication and psychosocial approaches. The high number of PRN events for physical reasons (60%) was not explained by the patient characteristics and urgent research is needed on this aspect. Protracted PRN use should be recognized in clinical practice, and consider more structured solutions to develop PRN protocols and evidence-based care. Future research should examine how PRN is integrated with patients’ regular treatment and non-pharmacological methods.


Document analysis, forensic nursing, pro re nata medication, psychiatric hospitals

Summary of the Research

“…PRN [pro re nata] medication is prescribed so that it can be taken as needed when acute physical and psychiatric health problems arise…PRN is prevalent in psychiatric inpatient settings…and studies have indicated that 70-90% of patients receive psychotropic PRN, medication used for psychiatric conditions…PRNs are also frequently used in forensic inpatients’ care…Studies have indicated that most PRN medication is administered to a minority of psychiatric inpatients…[however], have found different results with regard to the demographic background of these patients…Increased PRN use has been associated with both male…and female patients…and one review concluded that patients from nonwhite ethnic groups were more likely to receive PRN…” (p.329-330).

“Although PRN administration has been researched, studies have not tended to focus on its use by inpatients in forensic facilities…Furthermore, studies have focused on medication used to treat psychiatric conditions…and excluded medication used for physical reasons, even though they have been reported to be administered as frequently…Our aim was to fill those gaps in knowledge and to describe the prevalence of PRN events in a forensic hospital based on medical records. The study covered both psychiatric and physical reasons and we used the term PRN events to cover occasions on which PRN was documented to be considered, administered, or both…” (p.330).

“This study was conducted in one of the two state hospitals in Finland that provides forensic psychiatric services and mental examinations for the whole country…We found that PRN was commonly administered to this patient group and it was particularly used to alleviate patients’ pain, anxiety, and sleeping problems. However, the number of PRN events per patient was unevenly distributed and higher among dangerous or difficult-to-treat patients and patients who received neurostimulation therapy. PRN for both psychiatric reasons and insomnia were also associated with female gender and low daily functioning. PRN events for physical reasons were not related to patient characteristics” (p. 331-336).

“In our study, just over half of the patients received PRN for psychiatric reasons, which was lower than the 70-90% reported by studies…It should be noted that almost a half of the patients did not receive PRN for psychiatric reasons. This is significant, particularly because the patients we reviewed were diagnosed with psychotic illnesses and the majority were aggressive and difficult-to-treat. It has been reported that staff may be keen to administer psychotropic PRN to this patient group…Our results revealed that 60% of PRN events occurred for physical reasons and we felt this was high because patient care included regular physical health assessments and treatment…some of the physical reasons for PRN, such as headaches, constipation, and extrapyramidal symptoms, may have been derived from scheduled medication and their side effects…” (p.336).

“Female patients had more PRN events for both psychiatric reasons and insomnia…Gender-related differences in PRN use still need to be studied in the future. It could be that female patients experience anxiety and insomnia more often or that they are keener to use medication to alleviate these symptoms. Alternatively, female and male inpatients may be treated differently and have different opportunities to receive PRN…the number of PRN events was associated with GAF values, but not with violence screening values. This implies that the prevalence of PRN events could have been more affected by deficiencies in functioning than a propensity for violence…We did not find patient characteristics that would explain the frequency of PRN events for physical reasons…” (p.337).

Translating Research into Practice

“…If a patient needs PRN medication every day for the same reason, it would be better to consider more structured solutions. This would involve anticipating, and planning, non-pharmacological methods for each patients’ usual and individual psychiatric and physical health problems. Solutions need to be based on evidence-based practice, including patients’ preferences…PRN medication is one way to respond to patients’ psychiatric and physical acute needs. Our study concluded that PRN events were common among long-term patients in a forensic hospital and further research is needed, especially on PRN for pain and other reasons. Our results showed that psychotropic PRN is not used for all inpatients with psychotic illnesses and a high risk of violence, but it is linked to more severe deficiencies of functioning. In some situations, PRN can be the only option available, but it may be replaced by psychosocial approaches as the patient’s treatment proceeds” (p.337-338).

“Further research is needed to develop a more complete understanding of the relationship between PRN and scheduled medication. Studies should also focus on how to integrate PRN with regular treatment and non-pharmacological methods and how PRN is related to violent incidents. It is important that healthcare professionals communicate openly with patients, so that they understand how to promote their health, perceive different symptoms, identify indications for PRN, and explore non-pharmacological coping strategies” (p.338).

Other Interesting Tidbits for Researchers and Clinicians

“PRN was mainly administered orally, similar to previous studies. However, we found that intramuscular injections were exceptional, unlike other studies…Our result can partly be due to that we only included patients who were willing and capable of giving informed consent but also to the fact that national policy in Finland is to avoid chemical sedation” (p.336).

“A quarter of patients used PRNs on most days. Protracted PRN use may be caused by medically explained indications, but psychosomatic symptoms can also be an issue…We also wonder if some patients got into the habit of requesting PRNs or used them as a way of interacting with the staff. More research with different methods is needed to analyze possible reasons for the protracted use of PRN. Prolonged and repetitive use of PRNs raises doubts about the long-term outcomes of medication…” (p.336-337).

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Authored by Amber Lin

Amber Lin is a clinical psychology doctoral student at Fairleigh Dickinson University. Her research interests include forensic assessment, competency to stand trial, and the refinement of instruments used to assess the psychological states of criminal defendants.

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