A study to see if fluoxetine will help reduce the symptoms of problematic sexual arousal in adult men serving a prison sentence when compared with a placebo (dummy) drug
| ISRCTN | ISRCTN91246381 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN91246381 |
| Integrated Research Application System (IRAS) | 1007974 |
| Sponsor's protocol code number | NTU-FASAR-SPON-001 |
| Sponsor | Nottingham Trent University |
| Funder | National Institute for Health and Care Research |
- Submission date
- 05/02/2026
- Registration date
- 16/06/2026
- Last edited
- 22/10/2026
- Recruitment status
- Not yet recruiting
- Overall study status
- Ongoing
- Condition category
- Mental and Behavioural Disorders
Plain English summary of protocol
Background and study aims
Problematic sexual arousal (PSA) is characterised by persistent and intense sexual thoughts, physiological arousal, urges, and behaviours that are distressing and difficult to control. Prisons have people with symptoms of PSA being exhibited during their stay, not all of which are people with a sexual conviction.
Recent research has provided evidence for selective serotonin reuptake inhibitors (SSRIs) as an alternative treatment to testosterone-lowering medications. A number of research studies have been conducted into the use of various SSRIs (mainly sertraline and fluoxetine). These studies have reported promising results for the role of SSRIs in the treatment of PSA, including a less severe side effect profile and cost-effectiveness.
This trial aims to investigate whether fluoxetine can reduce PSA in patients who have been referred to the prison's Medication to Manage Problematic Sexual Arousal (MMPSA) service by comparing its effectiveness and cost effectiveness over a 6-month period when compared with patients taking a placebo drug.
Who can participate?
Adult (18 years or older) patients who have been referred to the prison's Medication to Manage Problematic Sexual Arousal (MMPSA) service.
What does the study involve?
We will undertake a double blind randomised controlled trial, recruiting at least 196 patients and randomising them to fluoxetine or a matching placebo in a 1:1 ratio so that there are equal numbers in each group. We will ask patients to complete questionnaires at baseline (before the blinded treatment is given), then at 3 and 6 months after the treatment has been started. Patients will complete a daily log to report any side effects, changes to other medications they are taking, and any healthcare contacts during the trial.
At the end of the 6-month trial period for each patient, the Forensic Psychiatrist will be unblinded and decide on their treatment as part of standard care.
The trial hopes to prove that fluoxetine is effective and cost effective to use in patients exhibiting PSA symptoms so that the guidelines can be amended to allow fluoxetine to be prescribed in the community.
What are the possible benefits and risks of participating?
Not provided at time of registration
Where is the study run from?
Nottingham Trent University (UK)
When is the study starting and how long is it expected to run for?
January 2027 to January 2028
Who is funding the study?
National Institute for Health and Care Research (NIHR) (UK).
Who is the main contact?
Dr Richard Emes, richard.emes@ntu.ac.uk
Prof Belinda Winder, belinda.winder@ntu.ac.uk
Contact information
Scientific, Public
50 Shakespeare Street
Nottingham
NG1 4FQ
United Kingdom
| Phone | +44 115 848 5574 |
|---|---|
| Richard.emes@ntu.ac.uk |
Principal investigator
50 Shakespeare Street
Nottingham
NG1 4FQ
United Kingdom
| belinda.winder@ntu.ac.uk |
Study information
| Primary study design | Interventional |
|---|---|
| Allocation | Randomized controlled trial |
| Masking | Blinded (masking used) |
| Control | Placebo |
| Assignment | Parallel |
| Purpose | Treatment, Efficacy |
| Scientific title | Randomised controlled trial of fluoxetine for the treatment of problematic sexual arousal in adult males serving a custodial sentence |
| Study acronym | FASAR |
| Study objectives | The primary objective of this trial is to determine whether fluoxetine prescribed over 6 months is effective in reducing problematic sexual arousal in adult males referred to the Medicines to Manage Problematic Sexual Arousal service in prisons when compared with placebo according to the trial-adapted Sexual Compulsivity Scale (SCS). Secondary objectives: 1. To determine the efficacy of fluoxetine (dose 20mg / 40mg / 60mg daily) for reducing PSA in adult males referred to the MMPSA service at 3 months compared to placebo according to the trial-adapted Sexual Compulsivity Scale (SCS). 2. To determine the efficacy of fluoxetine (dose 20mg / 40mg / 60mg daily) for improving wellbeing in adult males referred to the MMPSA service at 3 and 6 months compared to placebo according to the Warwick–Edinburgh Mental Wellbeing Scale (WEMWBS) for wellbeing. 3. To determine the efficacy of fluoxetine (dose 20mg / 40mg / 60mg daily) for improving anxiety and depression in adult males referred to the MMPSA service at 3 and 6 months compared to placebo according to the Hospital Anxiety and Depression Scale (HADS) for anxiety and depression. 4. To determine the efficacy of fluoxetine (dose 20mg / 40mg / 60mg daily) for reducing paedophilic and/or hebophilic interests in adult males referred to the MMPSA service at 3 and 6 months compared to placebo according to the Problematic Sexual Interest Questionnaire (PSIQ). 5. To assess the cost-effectiveness of fluoxetine compared to placebo using QALYs derived from the EQ5D-5L and the SCS at 3 and 6 months. 6. To understand the timing and motivations for change, prior help-seeking, and the service, treatment, and personal factors (including views on mandatory use, expectations, and expected continuation/discontinuation) that influence engagement with MMPSA collected in the Treatment Considerations questions in the PROMs booklet at baseline. 7. To understand participants' experiences, side-effects, wellbeing, and engagement over time while taking MMPSA, and how these factors influence continuation, perceptions of helpfulness, and evolving views on voluntary versus mandatory use collected in the Experience and Impact section of the PROMs booklet at 3 months and 6 months. To understand the triggers for and/or barriers to referring someone for medication and understand any systemic or individual barriers to people continuing with a referral. |
| Ethics approval(s) |
Submitted 20/04/2026, Wales Research Ethics Committee 3 (Health and Care Research Wales, Floor 4, Crown Building, Cathays Park, Cardiff, CF10 3NQ, United Kingdom; -; Wales.REC3@wales.nhs.uk), ref: 26/WA/0041 |
| Health condition(s) or problem(s) studied | Problematic sexual arousal |
| Intervention | The main study is designed as a double-blind randomised controlled superiority trial with two arms. Eligible consenting patients will be randomised to receive either fluoxetine (20mg capsule) or placebo (Microcrystalline cellulose). All patients will be reviewed at approximately 4 weeks, with the dose increased to 40mg if no or partial clinical response, and then to 60mg after a further approximately 4 weeks if needed. Maximum dose will be 60mg/day. Patients will be randomised on a 1:1 basis, stratified by site. The randomisation service will be provided by Sealed Envelope Ltd. (https://www.sealedenvelope.com) in consultation with the statistician based at STU. |
| Intervention type | Drug |
| Phase | Phase III |
| Drug / device / biological / vaccine name(s) | Fluoxetine [N-methyl-3-phenyl-3-[4-(trifluoromethyl)phenoxy]propan-1-amine] |
| Primary outcome measure(s) |
The efficacy of fluoxetine in reducing problematic sexual arousal in adult males referred to the Medication to Manage Problematic Sexual Arousal service compared to placebo as measured by the trial-adapted Sexual Compulsivity Scale at baseline and 6 months later. |
| Key secondary outcome measure(s) |
1. To determine the efficacy of fluoxetine for improving wellbeing in adult males referred to the MMPSA service compared to placebo using the Warwick–Edinburgh Mental Wellbeing Scale (WEMWBS) at 3 and 6 months. The WEMWBS consists of 14 positively phrased Likert items. The scoring range for each item is from 1–5 and the total score is from 14–70, with higher scores indicating greater wellbeing. |
| Completion date | 31/01/2028 |
Eligibility
| Participant type(s) | |
|---|---|
| Age group | Mixed |
| Lower age limit | 18 Years |
| Upper age limit | 99 Years |
| Sex | Male |
| Target sample size at registration | 196 |
| Key inclusion criteria | 1. Male. 2. Aged 18+ years. 3. Currently detained at one of the prison sites running the trial and referred to the MMPSA service 4. Total Sexual Compulsivity Scale score (used in standard care) of 15+ or a score of 3 or 4 on any one item. 5. Diagnosis of problematic sexual arousal made by a Forensic Psychiatrist or other relevant specialist. 6. Clinician determination that it is appropriate to prescribe fluoxetine. 7. Understands written and verbal English sufficiently to have the trial explained to them. 8. Has the capacity to give informed consent. 9. Agrees to use appropriate contraceptive methods during the trial and for 6 months after. |
| Key exclusion criteria | 1. Current pharmacological treatment with an SSRI/anti-androgen/Gonadotropin-releasing hormone agonist. 2. Contraindication to Selective serotonin reuptake inhibitors. 3. Major mental illness (e.g. schizophrenia or other psychotic disorders) if acutely unwell and therefore unable to give informed consent. 4. Patients with epilepsy. 5. Currently prescribed medication that interacts with the 5-HT system, meaning it has serotonin effects. 6. Currently on prophylactic medication that has an impact on sexual arousal. 7. Currently prescribed testosterone/oestrogen supplement therapy. 8. Risk of harm to self/others is deemed too high to be randomised to placebo. 9. Planned release date is within 9 months (including shortened sentences). 10. Prison transfer to a prison where Medication to Manage Problematic Sexual Arousal service is not available within the next 9 months is highly likely or actually planned. |
| Date of first enrolment | 11/01/2027 |
| Date of final enrolment | 30/06/2027 |
Locations
Countries of recruitment
- United Kingdom
- England
- Wales
Study participating centre
-
-
England
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan | The datasets generated during and/or analysed during the current study are/will be available upon request. The CI and trial statistician will have access to the final dataset. Should PIs or others require access to the final dataset, this will require approval by the TMG, TSC and Sponsor and will only be made available following trial completion and publication. A data sharing agreement may be required. |
Editorial Notes
22/10/2026: The date of first enrolment was changed from 02/11/2026 to 11/01/2027.
08/09/2026: The date of first enrolment was changed from 01/10/2026 to 02/11/2026.
06/07/2026: Ethics approval details added. The date of first enrolment was changed from 31/03/2026 to 01/10/2026.
05/02/2026: Trial's existence confirmed by NHS HRA.
