Safety of ciprofloxacin and risk of suicidality: a case control study in UK primary care using the Clinical Practice Research Datalink.

PI Title: Dr Richard Partington

Lead member: Keele

Ciprofloxacin is an antibiotic used to treat a wide variety of commonly occurring bacterial infections, for example chest infections, water infections, and infections of the prostate gland (prostatitis). In common with all prescribed medicines, it can cause adverse side effects. One of these side effects is thought to be an increased risk of completed suicide or suicidal thoughts.

This year, a patient who had no history of mental health problems completed suicide after being prescribed ciprofloxacin. The coroner felt the prescribing doctor had not placed enough emphasis on the potential risk of suicide, due to many prescribers being unaware of this potential adverse event and sent a report to prevent future deaths to the Medicines and Healthcare Products Regulatory Authority (MHRA), the organisation that regulates medicines in the United Kingdom.

Some studies have reported that ciprofloxacin is associated with an increased risk of suicide, but others have disagreed. Therefore, it is not clear whether ciprofloxacin increases a patient’s risk of suicide. This lack of certainty is because completed suicide is very rare, and many other factors may affect a person’s risk. For example, the person receiving ciprofloxacin will be prescribed it due to an infection, which itself may cause a person to feel unwell or even confused.

Using the Clinical Practice Research Datalink (CPRD), we will compare patients with a history of completed suicide, attempted suicide, or those who have been identified to be at medium to high risk of suicide, to find out:
• Are they more likely to have received a prescription for ciprofloxacin in the six months beforehand?
• Are there any groups at patients at higher risk of suicide or suicidal thoughts when taking ciprofloxacin?

Amount awarded: £17,360