Pharmacoepidemiology and drug safety- High perceived sensitivity to medicines.

Purpose
The belief that one is especially sensitive to the actions and side effects of medicines can influence treatment adherence and side-effect reporting. In this study, we investigated the prevalence of perceived medication sensitivity in the general population and its relationship to symptom complaints, information seeking about medications, use of medical care and demographic factors.

Methods
A nationally representative sample of 1000 New Zealand residents completed the Perceived Sensitivity to Medicines scale and symptoms experienced during the previous 7 days. Demographic data and medical visits, medication use and information seeking about medicines were also collected.

Results
Over 20% of the general population reported being very sensitive to the effects of medication (20.2%) and that small amounts of medicines can upset their body (25.3%). Participants who reported high levels of perceived sensitivity to medicines reported significantly more symptoms (M = 9.54, SE = 0.47) than people with low (M = 5.04, SE = 0.49) or moderate (M = 5.91, SE = 0.24) levels, ps < .001. This relationship was strongest in participants who were currently taking prescription medication. Those with high perceived sensitivity also reported being more likely to seek information about medicines, and had significantly more general practitioner visits.

Conclusions
Perceived sensitivity to medicines is common in the population and associated with important clinical variables including information seeking, GP visits and symptom reporting. Identifying patients with higher perceived sensitivity to medicines may improve patient care by providing the basis for targeted and personalised interventions to reduce side effects and improve adherence to medications.