Background Oral route is safer and less costly than intravenous route; however, sometimes intravenous therapy is used longer than necessary. Paracetamol and omeprazole are two widely used drugs in hospitalised patients whose oral presentation have a biodisponibility similar to intravenous presentation; therefore, both are good options for sequential therapy.

Purpose To implement and to analyse a program to promote sequential therapy with paracetamol and omeprazole in a general public hospital with 120 beds.

Materials and methods Prospective study in hospitalised patients for 2 months (July–August 2011). The program consisted on a daily checking of intravenous paracetamol and intravenous omeprazole prescriptions by a pharmacist. If the patient could tolerate oral diet, a proposal to change to oral presentation was made. The recommendation is transmitted to prescribers by the electronic prescription program. Interventions were registered in a database and classified as accepted: change to oral presentation and rejected: no change after 5 days. Demographic characteristics were collected. Economic impact was assessed, analysing costs reduction with regard to cost drugs.

Results 76 interventions were recorded (86.8% paracetamol, 13.2% omeprazole). 73 patients (53.9% men) were included; mean age 77.5 years. Mainly, patients were admitted to internal medicine (67.1%). 39.5% (paracetamol: 30.3%, omeprazole: 50.0%) of recommendations were accepted; 15.8% (paracetamol: 15.2%, omeprazole: 20.0%) of patients were discharged or medication was removed the same day; 44.7% (paracetamol: 45.5%, omeprazole: 30%) of recommendations were rejected due to patients' oral tolerability worsened. Mean response time was 0.9 days. Cost savings were 342 (paracetamol: 327, omeprazole: 15) euros.

Conclusions 39.5% of recommendations resulted in change in patients' pharmacotherapy. Pharmaceutical validation improves efficiency of pharmacotherapy. Cost savings is not very high since the cost of these drugs is low. Similar programs could be implemented in some antibiotics to achieve greater savings.