[Follow-up of analytical parameters in Internal Medicine patients to detect adverse events]

To analyze the prevalence of prescription drugs, previously selected, that should be monitored by their analytical test, and the rate of alteration in these tests, with the aim of establishing priorities to facilitate monitoring.

Prospective observational study in the Internal Medicine department of a referral hospital of 350 beds. In a first phase, we selected some drugs which analytical monitoring is recommended for the medical literature, and after that, we reviewed the pharmacological treatment of all patients admitted with any of these drugs. The study was conducted in the last two month of 2011.

We included 271 patients, 128 (47%) were women. The mean age was 74.5 ± 14.4 years and the average stay of 7 ± 5.8 days. These patients accounted for 83% of all patients admitted to Internal Medicine during the study period. There were 828 drugs that must be monitored; each patient had an average of 3.1 ± 2.3. We reviewed 1837 analytical test, of which 401 (22%) were altered and 154 patients (57%) were affected for it. The pairs drug-analytical test altered most frequently found were creatinine increased and nephrotoxic drugs, hypokalemia in patients taking high efficiency diuretics and thrombocytopenia in patients treated with low molecular weight heparins.

Our study highlights the importance of monitoring laboratory test associated with some drugs from the pharmacy department, as it demonstrates a high incidence of warning results. Our proposal for selection of drugs makes monitoring easier, and reaches large numbers of patients.