Impact of chronic medications in the perioperative period: mechanisms of action and adverse drug effects (Part I).

Background: This review article discusses the pharmacology of the most commonly used chronic medications in patients undergoing elective surgical procedures. The mechanism of action and adverse side effects of cardiovascular medications (e.g., beta blockers, alpha-2 agonist, calcium channel blockers, ACE inhibitors, diuretics), lipid-lowering drugs, gastrointestinal medications (H2-blockers, proton pump inhibitors), pulmonary medications (inhaled β-agonists, anticholinergics,), antibiotics (tetracyclines, clindamycin and macrolide, linezolid), opioids and non-opioids analgesics (NSAIDs, COX-2 inhibitors, acetaminophen), gabapentanoids, erectile dysfunction (ED) drugs, and psychotropic drugs (tricyclic antidepressants [TCAs], monoamine oxidase inhibitors [MAOI], selective serotonin reuptake inhibitors [SSRIs], serotonin norepinephrine reuptake inhibitors [SNRIs], and cannabinol-containing drugs) will be reviewed.Materials and Methods: An online search was conducted from January 2000 through February 2021 with the Medline database through PubMed and Google Scholar using the following search terms/keywords: "chronic medications in the perioperative period", and "chronic medications and anesthetic implications." In addition, we searched for anesthetic side effects associated with the major drug groups.Results and Conclusions: An understanding of the pharmacology and pharmacokinetics of most used chronic medications is important to avoid untoward outcomes in the perioperative period. These drug interactions may result in altered efficacy and toxicity of the anesthetic medications administered during surgery. These drug-drug interactions can also effect the morbidity, mortality, and recovery time of surgical patients. Part I of this two-part review article focuses on the mechanisms of action and adverse side effects of the chronic medications most commonly taken by surgical patients in the preoperative period.