Check the product, concentration and units before every injection.
Glargine products require supervised switching. Toujeo U-300 and U-100 glargine are not interchangeable by volume. Never withdraw insulin from a pen with a syringe, share a pen, or inject glargine intravenously. Severe hypoglycemia needs emergency treatment.
Warnings and precautionsIndications
Basal glucose control in diabetes; formulation and pediatric wording differ.
Labeled subcutaneous indications
Lantus, Semglee and Rezvoglar labels indicate adult and pediatric diabetes mellitus; their pediatric evidence derives from type 1 diabetes ages 6–15 and adult studies. Toujeo explicitly indicates diabetes in adults and children ≥6 years. Basaglar specifically indicates adult/pediatric type 1 diabetes and adult type 2 diabetes; pediatric type 2 use and type 1 use below 6 are not established. Do not assign one universal minimum age to every product.
Clinical role and limitations
All selected products are basal insulin and are not recommended for treating diabetic ketoacidosis. In type 1 diabetes, combine with short-/rapid-acting premeal insulin. This profile excludes fixed insulin glargine/lixisenatide combinations and individualized emergency insulin protocols.
Dosage and administration
Prescribe units for the exact product and adjust using glucose results.
Initial basal dosing · Product-specific labels
These starting regimens require individual assessment; they are not a total insulin prescription.
| Product / situation | Starting regimen |
|---|---|
| Lantus / Basaglar / Semglee / Rezvoglar · type 1 | Approximately one-third of total daily insulin requirements as basal; premeal insulin supplies the remainder. |
| U-100 products · insulin-naive type 2 | 0.2 units/kg or up to 10 units once daily, followed by supervised titration. |
| Toujeo · insulin-naive type 1 | Basal approximately one-third to one-half of total daily insulin. Label rule-of-thumb initial TOTAL insulin: 0.2–0.4 units/kg/day; remainder as mealtime insulin. |
| Toujeo · insulin-naive type 2 | 0.2 units/kg once daily. |
| Toujeo titration | Adjust no more often than every 3–4 days. Full glucose-lowering effect may take 5 days; monitor daily at initiation. |
Switching basal insulin
Increase glucose checks during changes and early follow-up; other diabetes medicines may also need adjustment.
| Switch | Selected label instruction |
|---|---|
| Toujeo U-300 → Lantus / Basaglar / Semglee / Rezvoglar U-100 | Start at 80% of the discontinued U-300 daily unit dose. |
| Once-daily long/intermediate basal → Toujeo | Start at the same daily unit dose. A higher eventual Toujeo dose than Lantus may be needed. |
| Twice-daily NPH / detemir → Toujeo | Start at 80% of total daily twice-daily NPH or detemir units. |
| Twice-daily NPH → selected U-100 glargine | Start at 80% of total daily NPH units. |
| Once-daily NPH → Lantus / Semglee / Rezvoglar | Same starting units as discontinued once-daily NPH. Basaglar requires individualized intermediate-insulin conversion. |
| Another U-100 glargine → Basaglar | Basaglar label specifies the same unit dose, with supervised monitoring. |
Administration and pen dose limits
Inject once daily at the same time under the skin of abdomen, thigh or upper arm. Rotate sites; avoid pits, thickened skin or amyloid lumps. Use only clear, colorless solution. Do not mix, dilute, use in a pump, or administer intravenously. A pen displays actual units; no concentration calculation is needed. Never withdraw from a pen with a syringe.
- Toujeo SoloStar
- 450 units/1.5 mL; 1-unit increments, up to 80 units/injection.
- Toujeo Max SoloStar
- 900 units/3 mL; 2-unit increments, up to 160 units/injection; recommended if needing ≥20 units/day. Odd-unit conversion between pens requires clinician-directed ±1 unit.
- U-100 pens
- 1-unit increments. Basaglar, Rezvoglar, Lantus SoloStar and Semglee pen instructions limit a single injection to 80 units.
Renal, hepatic and changing insulin needs
No fixed renal/hepatic adjustment is provided. Monitor more often and individualize units with changes in renal/hepatic function, meals, activity, acute illness or other medicines. Do not apply an arbitrary dose ceiling: device limits describe one injection rather than a maximum daily prescription.
Safety
Hypoglycemia is the central risk; concentration and device errors can be fatal.
Warnings and precautions
- Severe hypoglycemia can cause seizure, coma or death. Renal/hepatic impairment, missed meals, activity changes and interacting medicines increase risk; reduced warning symptoms require more frequent checks.
- Never share pens, syringes or needles, even with a new needle. Check product and concentration every injection; never use a syringe to extract pen contents.
- Changes in brand, concentration, injection site or technique require supervision and extra glucose monitoring. Moving from a repeatedly used abnormal site to healthy skin can cause hypoglycemia.
- Insulin moves potassium into cells; monitor potassium in patients at risk. Severe low potassium can cause arrhythmia or paralysis.
- Anaphylaxis requires stopping the product and emergency treatment. TZDs with insulin can cause fluid retention or worsen heart failure; review swelling, dyspnea or sudden weight gain.
Contraindications
Do not administer during an episode of hypoglycemia or with hypersensitivity to insulin glargine/the selected product’s ingredients.
Boxed warning status
The selected U.S. labels have no boxed warning. Severe hypoglycemia, medication errors, anaphylaxis, hypokalemia and infection from sharing devices remain important labeled risks.
Adverse reactions and overdose
Hypoglycemia, weight gain, edema, injection-site reactions, lipodystrophy and localized cutaneous amyloidosis are reported. Immunogenicity occurs; antibody tests and trial adverse-event rates are not directly comparable across products. Excess insulin can cause prolonged/recurrent hypoglycemia and hypokalemia. Treat mild lows with oral carbohydrate if able to swallow; severe symptoms need emergency glucagon or IV glucose and continued observation. Do not give food/drink to an unconscious person.
Drug interactions
Other medicines can change glucose control or mask warning symptoms.
Clinically relevant interactions
| Combination | Action |
|---|---|
| Other glucose-lowering agents; ACE inhibitors/ARBs, salicylates, fluoxetine, selected antibiotics | Hypoglycemia risk may rise; more glucose checks and an insulin reduction may be needed. |
| Corticosteroids, atypical antipsychotics, sympathomimetics, thyroid hormones, selected hormones/diuretics | Glucose-lowering effect may decline; monitor and adjust insulin if needed. |
| Alcohol, beta-blockers, clonidine, lithium; pentamidine | Glucose response may increase or decrease; pentamidine can cause lows followed by highs. Monitor closely. |
| Beta-blockers, clonidine, guanethidine, reserpine | May mask hypoglycemia symptoms; rely on more frequent glucose checks. |
| TZDs such as pioglitazone | Monitor fluid retention/heart failure; consider TZD reduction or discontinuation if heart failure develops. |
Use in specific populations
Individualize treatment across pregnancy, childhood, older age and organ dysfunction.
Pregnancy and lactation
Published glargine pregnancy studies have not established a clear association with adverse developmental outcomes; observational limitations remain. Poor glycemic control poses maternal/fetal risks, and both low and high glucose require attention. Human milk data are absent or limited; endogenous insulin is in milk. Balance maternal treatment and breastfeeding benefits with potential infant effects and monitor changing insulin needs.
Pediatric considerations
Toujeo is labeled ≥6 years; not established below 6. Basaglar pediatric type 1 evidence is ages 6–15; below 6 and pediatric type 2 are not established. Lantus, Semglee and Rezvoglar have broad pediatric diabetes indication wording supported by type 1 ages 6–15 plus adult studies; their selected labels do not state the same explicit minimum as Toujeo. Pediatric type 1 trial severe hypoglycemia was more frequent than in adult trials; specialist dosing and caregiver training are essential.
Older adults and renal/hepatic impairment
Use conservative initiation and increments in older adults, where lows may be harder to recognize. Kidney/hepatic effects on glargine pharmacokinetics have not been directly studied adequately; frequent glucose checks and dose adjustment may be necessary. No eGFR-based fixed unit adjustment is supplied.
Clinical pharmacology
Glargine supplies sustained basal insulin activity after subcutaneous injection.
Mechanism of action
Insulin promotes peripheral glucose uptake and suppresses hepatic glucose output. It also inhibits lipolysis/proteolysis and promotes protein synthesis. Glargine’s subcutaneous absorption provides prolonged basal activity.
Pharmacodynamics and pharmacokinetics
Time-action profiles vary within and between patients; do not promise a fixed duration for every injection.
- U-100
- Relatively constant concentrations with no pronounced peak versus NPH over 24 hours. Lantus clamp median effect was 24 hours; range included 10.8 to >24 hours.
- U-300
- Onset develops over approximately 6 hours in single-dose clamp studies; steady-state concentrations reached by at least 5 days. Unit-for-unit glucose-lowering effect differs from U-100.
- Metabolism
- Subcutaneous/circulating active metabolites M1 and M2 have insulin-like activity.
- Dose interpretation
- Pen units do not require volume conversion; pharmacologic differences still require product-specific switching and titration.
Monitoring and counseling
Glucose monitoring and injection education prevent avoidable harm.
Monitoring parameters
- Monitor glucose according to the individualized plan; increase checks during brand/concentration changes, illness, meals/activity changes or impaired low-glucose awareness.
- Review hypoglycemia episodes, injection sites, technique, adherence and storage. Check glycemic progress and whether basal/mealtime balance remains appropriate.
- Check potassium in at-risk patients; follow weight, edema and heart failure symptoms with TZDs.
- Review kidney/hepatic function changes and interacting drugs; reassess dose under medical supervision.
Patient counseling information
- Read the exact device instructions, prime as directed, use a new needle each time and remove it after injection. Confirm product, concentration and prescribed units.
- Never share any pen or needle; do not transfer insulin from a pen to a syringe. Use the correct U-100 syringe only for a U-100 vial.
- Carry a low-glucose treatment plan and teach caregivers emergency glucagon use. Discuss safe driving and alcohol; lows may recur because this insulin lasts a long time.
- Rotate healthy injection sites; keep a clinician-directed plan for missed doses/illness. Do not stop necessary basal insulin or double a dose without guidance.
Product identification
Identify concentration and device using the labeled package.
Representative injectable product · Lantus SoloStar
- Dosage form / concentration
- Clear, colorless solution · U-100 (100 units/mL)
- Presentation
- 3 mL single-patient-use prefilled SoloStar pen · 300 total units
- Manufacturer
- Sanofi-aventis U.S. LLC
- Example NDC
- 0088-2219-05 · five pens
Dosage forms and strengths
| Product | Selected presentations |
|---|---|
| Lantus U-100 | 10 mL vial; 3 mL SoloStar pen |
| Basaglar U-100 | 3 mL KwikPen and Tempo Pen |
| Semglee (glargine-yfgn) U-100 | 10 mL vial; 3 mL prefilled pen |
| Rezvoglar (glargine-aglr) U-100 | 3 mL KwikPen |
| Toujeo U-300 | 1.5 mL SoloStar (450 units); 3 mL Max SoloStar (900 units) |
Storage and handling
Store unopened selected products refrigerated at 2–8°C until labeled expiry; protect from heat/light and do not freeze. Discard if frozen. Follow the exact product/device instructions and write the opening/discard date.
| Presentation | In-use / room-temperature rule |
|---|---|
| Lantus / Semglee U-100 vial | 28 days refrigerated or ≤30°C. Unopened room-temperature storage is also limited to 28 days. |
| Lantus / Basaglar / Semglee / Rezvoglar U-100 pen | 28 days at ≤30°C; do not refrigerate once in use. Room-temperature unopened storage counts toward product limits. |
| Toujeo SoloStar / Max SoloStar U-300 | 56 days once in use at ≤30°C; do not refrigerate in-use pens. Keep cap on; selected manufacturer table specifies unopened refrigerated storage until expiry. |
References
Original sources for the clinical and product information.
- DailyMed / National Library of MedicineLantus · U-100 vial and SoloStar
Full public manufacturer label and patient instructions; SPL version 35, effective 20250602. Product-specific directions reviewed October 1, 2026.
- DailyMed / National Library of MedicineToujeo · U-300 SoloStar and Max SoloStar
Full public manufacturer label and patient instructions; SPL version 25, effective 20250530. Product-specific directions reviewed October 1, 2026.
- DailyMed / National Library of MedicineBasaglar · U-100 KwikPen and Tempo Pen
Full public manufacturer label and patient instructions; SPL version 35, effective 20260616. Product-specific directions reviewed October 1, 2026.
- DailyMed / National Library of MedicineSemglee · insulin glargine-yfgn U-100
Full public manufacturer label and patient instructions; SPL version 14, effective 20250303. Product-specific directions reviewed October 1, 2026.
- DailyMed / National Library of MedicineRezvoglar · insulin glargine-aglr U-100
Full public manufacturer label and patient instructions; SPL version 7, effective 20240809. Product-specific directions reviewed October 1, 2026.