Practical guidance on the initiation, titration, and switching of basal insulins: a narrative review for primary care

Many patients with type 2 diabetes will ultimately require the inclusion of basal insulin in their treatment regimen. Since most people with type 2 diabetes are managed in the community, it is important that primary care providers understand and correctly manage the initiation and titration of basal insulins, and help patients to self-manage insulin injections. Newer, long-acting basal insulins provide greater stability and flexibility than older preparations and improved delivery systems. Basal insulin is usually initiated at a conservative dose of 10 units/day or 0.1-0.2 units/kg/day, then titrated thereafter over several weeks or months, based on patients' self-measured fasting plasma glucose, to achieve an individualized target (usually 80-130 mg/dL). Through a shared decision-making process, confirmation of appropriate goals and titration methods should be established, including provisions for events that might alter scheduled titration (e.g. travel, dietary change, illness, hospitalization, etc.). Although switching between basal insulins is usually easily accomplished, pharmacokinetic and pharmacodynamic differences between formulations require clinicians to provide explicit guidance to patients. Basal insulin is effective long-term, but overbasalization (continuing to escalate dose without a meaningful reduction in fasting plasma glucose) should be avoided.Key messagesPrimary care providers often initiate basal insulin for people with type 2 diabetes.Basal insulin is recommended to be initiated at 10 units/day or 0.1-0.2 units/kg/day, and doses must be titrated to agreed fasting plasma glucose goals, usually 80-130 mg/dL. A simple rule is to gradually increase the initial dose by 1 unit per day (NPH, insulin detemir, and glargine 100 units/mL) or 2-4 units once or twice per week (NPH, insulin detemir, glargine 100 and 300 units/mL, and degludec) until FPG levels remain consistently within the target range. If warranted, switching between basal insulins can be done using simple regimens.The dose of basal insulin should be increased as required up to approximately 0.5-1.0 units/kg/day in some cases. Overbasalization (continuing to escalate dose without a meaningful reduction in fasting plasma glucose) is not recommended; rather re-evaluation of individual therapy, including consideration of more concentrated basal insulin preparations and/or short-acting prandial insulin as well as other glucose-lowering therapies, is suggested.