Adverse Effects of Common Drugs: General Concepts.

Adverse drug reactions (ADRs) contribute to substantial morbidity and mortality and add to rising health care costs. Many ADRs are preventable with appropriate prescribing and monitoring because they often occur as an extension of a drug's mechanism of action or known drug interactions. Patients at higher risk of ADRs include those at the extremes of age, those with multiple comorbidities, those taking multiple drugs, and patients admitted to intensive care units or experiencing transitions of care. Because the risk of ADRs becomes greater as the number of drugs and dietary supplements taken increases, it is imperative that prescribers be vigilant about the prescribing cascade and take steps to discontinue drugs that are likely to be more harmful than helpful. Pharmacists serve as important partners in clinical care environments by conducting comprehensive drug reviews, aiding in drug/dosage selection, and developing therapeutic monitoring plans. Although the potential exists for clinicians to use electronic health record systems to aid in clinical decision making through drug safety decision support tools, computer systems should never replace clinical judgment. Clinicians also are encouraged to report ADRs to the Food and Drug Administration Adverse Event Reporting System.

Adverse Effects of Common Drugs: Children and Adolescents.

Drug use and harms are increasingly common among newborns, infants, children, and adolescents during ambulatory practice, emergency department, and in-hospital treatment, including treatment in pediatric intensive care units. The pharmacokinetic and pharmacodynamic parameters of drugs often are different for children compared with adults and must be considered before prescribing. Drug exposure and the potential for harms also should be considered for fetuses and breastfeeding infants. As with adult patients, a thorough drug and allergy history (including nonprescription drugs and herbal and dietary supplements) should be obtained and reviewed at each medical visit. Children and adolescents are increasingly at risk of drug harm/overdose through accidental or intentional ingestion of nonprescription and prescription drugs (eg, cough and cold preparations, candy-appearing vitamins, stimulants, narcotics). Parents and caregivers should receive training in the proper use, storage, and administration of all drugs. Prescribing clinicians should be vigilant in withholding unnecessary drugs, such as antibiotics for viral infections. When prescribing, clinicians should be aware of common drugs frequently associated with adverse reactions, including stimulants, antipsychotics, analgesics, asthma therapies, acne therapies, and tumor necrosis factor inhibitors. Scientifically based prescribing practices should be used and consultation with evidence-based resources and pharmacists sought as needed.

Adverse Effects of Common Drugs: Dietary Supplements.

Dietary supplement-induced adverse effects often resolve quickly after discontinuation of the offending product, especially in younger patients. The potential for unwanted outcomes can be amplified in elderly patients or those taking multiple prescription drugs, especially where interactions exist with drugs metabolized by cytochrome P450 enzymes. Attributing injury or illness to a specific supplement can be challenging, especially in light of multi-ingredient products, product variability, and variability in reporting, as well as the vast underreporting of adverse drug reactions. Clinicians prescribing a new drug or evaluating a patient with a new symptom complex should inquire about use of herbal and dietary supplements as part of a comprehensive evaluation. Clinicians should report suspected supplement-related adverse effects to the local or state health department, as well as the Food and Drug Administration's MedWatch program (available at https://www.safetyreporting.hhs.gov). Clinicians should consider discussing suspected adverse effects involving drugs, herbal products, or dietary supplements with their community- and hospital-based pharmacists, and explore patient management options with medical or clinical toxicology subspecialists.

Adverse Effects of Common Drugs: Adults.

Although drugs can be an essential and lifesaving component of the care of adult patients, their use frequently is accompanied by adverse effects and life-threatening adverse drug reactions that can result in significant disability and mortality. The potential for drug-related severe morbidity and mortality is compounded during periods of hospitalization, when high-risk drugs such as anticoagulants or insulin are used, and when care in an intensive care unit is required. Patient factors in adults that can increase the risk of drug harms include immunosuppression, cognitive impairment, depression, alcoholism and other substance abuse disorders, chronic kidney disease, hepatic dysfunction, coagulopathies, limited English proficiency, institutional/nursing home care, and underinsurance or lack of insurance. Physician factors that can increase the risk of drug harms include inappropriate prescribing of drugs (including to pregnant and breastfeeding women), failure to appropriately discontinue/deprescribe drugs, insufficient drug reconciliation, failure to coordinate care among multiple prescribing clinicians, and failure to elicit and incorporate into health histories and clinical decision-making the widespread use of nonprescription drugs, herbal products, and dietary supplements.