Background and Importance There is a need to carefully prescribe drugs with a narrow therapeutic range and pharmacokinetic reports on their serum concentrations are the necessary tool for this commitment.

Aim and Objectives Evaluate the impact of pharmacokinetic reports on clinical decision.

Material and Methods A prospective analysis was conducted in a secondary care hospital between March and August 2020 including adult patients with at least one serum concentration of valproic acid, amikacin, carbamazepine, cyclosporine, digoxin, phenytoin, phenobarbital, lithium, gentamicin, theophylline, vancomycin and voriconazole.

Dialyzed and non-admitted patients were excluded. Data was obtained from medical records and pharmacokinetic software. The variables collected were: age, sex, prescribed drug, clinical department, pharmacokinetic report and medical decision.

Results 166 patients with 613 pharmaceutical interventions were recorded. Ninety-five (57.2%) were women with a mean age of 73 years (28-100), mean weight 66 kg (40.5-139.2) and mean serum creatinine 1 mg/dL (0.3-12.5).

The number of pharmacokinetic reports were digoxin: 265 (43.2%); vancomycin: 139 (22.7%); valproic acid: 79 (12.9%); lithium: 69 (11.3%); amikacin: 17 (2.8%); carbamazepine: 10 (1.6%); theophylline: 9 (1.5%); phenytoin: 8 (1.3%); gentamicin: 8 (1.3%); cyclosporine: 4 (0.7%); phenobarbital: 3 (0.5%); voriconazole: 2 (0.3%).

Pharmacokinetic reports according to the prescribing clinical department: internal medicine: 223 (36.4%), psychiatry: 100 (16.3%); and cardiology: 71 (11.6%) were the main ones.

The physician's acceptance of the pharmacokinetic reports according to the drug were digoxin: 112 (37.6%); vancomycin: 74 (24.8%); valproic acid: 43 (14.4%); lithium: 38 (12.8%); amikacin: 13 (4.4%); phenytoin: 4 (1.3%); theophylline: 4 (1.3%); gentamicin: 3 (1.0%); carbamazepine: 2 (0.7%); cyclosporine: 2 (0.7%); phenobarbital: 2 (0.7%); voriconazole: 1 (0.3%).

Acceptance of pharmaceutical recommendations by major clinical services were internal medicine: 110 (36.9%); psychiatry: 54 (18.1%); and geriatrics: 32 (10.7%).

Accepted recommendations were dose maintenance: 202 (75.4%); dose suspension: 26 (72.2%); dose reduction: 41 (68.3%); dose increase: 26 (66.7%).

The pharmacokinetic reports accepted 295 (73.2%). 8% were not accepted due to patient discharge or death.

Conclusion and Relevance A pharmacokinetic area supports clinicians in order to establish the safest and most effective dosing regimens.

A high percentage of pharmacokinetic reports were accepted, however, it is necessary to increase this percentage by talking to physicians and remarking the importance of this activity.

Conflict of Interest No conflict of interest