Background Some patients get prescriptions from the Primary Care Physician (PCP) and the Specialist Attention Physician (SAP) at the same time, without pharmaceutical validation to detect potential interactions between them.

One example is antiretroviral and antineoplastic drugs given concomitantly with antiulcer treatment. Combination of these drugs leads to the decreased absorption and the consequent loss of efficacy of antiretrovirals and antineoplastics.

Purpose To identify patients who are under antiretroviral/antineoplastic and antiulcer treatment concomitantly.

To suggest suitable antiulcer treatment to PCPs and SAPs.

To evaluate the effect of this strategy.

Material and methods Patients on treatment with rilpivirine, erlotinib, gefitinib, dasatinib and lapatinib were identified from the Hospital Pharmacy Outpatient Unit.

Patients on treatment with proton pump inhibitors (PPI) and H₂ receptor antagonists (H₂RA) were identified from the Primary Care Information System, from May 2014 to September 2014.

Once our target patients were identified, the Primary Care Pharmacy Department reported the interaction to the PCPs involved, suggesting either a switch from PPI to H₂RA, a dosage modification or treatment termination.

Results 16 patients were identified.

Mean age was 66.8 years (range 49–82); 68.75% men.

Treatments: 1 patient rilpivirine plus PPI, 6 erlotinib plus PPI, 1 erlotinib plus antiH₂, 4 gefitinib plus PPI, 2 dasatinib plus PPI and 2 lapatinib plus PPI.

After notification, 4 patients had a change in their treatments (25%), mean age 64.8 years (range 59–68) 75% men: 2 PPI treatment terminations and 2 switches from PPI to H₂RA.

Conclusion It is necessary improves coordination between Primary Care Pharmacy and Hospital Pharmacy to identify and minimise drug-related problems.

Moreover, it would be advisable to develop a unique medicines record in order to provide effective pharmaceutical care. A better tool of communication with physicians should be investigated because the effect of the intervention was moderate (25%).

References and/or Acknowledgements No conflict of interest.