Evaluation of common prescription analgesics and adjuvant analgesics as markers of suicide risk: a longitudinal population-based study in England.

BACKGROUND

Analgesics prescriptions may provide a marker for identifying individuals at higher risk of suicide. In particular, awareness of which analgesics are implicated may help clinicians assess and modify risk.

METHOD

A case-control study in England using the Clinical Practice Research Datalink (for primary care records) linked with hospital and national mortality electronic registries. We included patients aged ≥15 who died by suicide between 2001 and 2019 (N = 14,515), to whom we individually matched 580,159 controls by suicide date and general practice (N = 594,674). Odds ratios (ORs) for suicide, controlled for age and sex, were assessed using conditional logistic regression.

FINDINGS

Suicide risks were highest in those prescribed adjuvant analgesics (pregabalin, gabapentin and carbamazepine) (adjusted OR 4.07; 95% confidence intervals CI: 3.62-4.57), followed by those prescribed opioids (adjusted OR 2.01; 95% CI: 1.88-2.15) and those prescribed non-opioid analgesics (adjusted OR 1.48; 95% CI: 1.39-1.58) compared to those not prescribed these medications. By individual analgesic, the highest suicide risks were seen in patients prescribed oxycodone (adjusted OR 6.70; 95% CI: 4.49-9.37); pregabalin (adjusted OR 6.50; 95% CI: 5.41-7.81); morphine (adjusted OR 4.54; 95% CI: 3.73-5.52); and gabapentin (adjusted OR 3.12; 95% CI: 2.59-3.75). Suicide risk increased linearly with the number of analgesic prescriptions in the final year (p < 0.01 based on the likelihood ratio test), and the more different analgesics categories were prescribed in the final year (p < 0.01 based on the likelihood ratio test).

INTERPRETATION

Analgesic prescribing was associated with higher suicide risk. This is a particular issue with regard to adjuvant non-opiate analgesics.

FUNDING

There was no funding for this study.