Insuman Basal SoloStar: Uses, Dosage & Side Effects

What Is Insuman Basal SoloStar and What Is It Used For?

Insuman Basal SoloStar contains the active substance insulin human in the isophane (also known as NPH – Neutral Protamine Hagedorn) formulation. Isophane insulin is created by combining regular human insulin with protamine sulfate and zinc chloride to form a crystalline suspension. This crystalline complex slows the absorption of insulin from the subcutaneous injection site, resulting in a longer-lasting effect compared with regular (soluble) insulin. The insulin human in Insuman Basal is produced by recombinant DNA technology using the bacterium Escherichia coli (K12 strain), which has been genetically modified to produce human insulin that is structurally identical to the insulin produced by the human pancreas.

Insulin is a naturally occurring hormone produced by the beta cells of the islets of Langerhans in the pancreas. It plays a central role in glucose metabolism by binding to insulin receptors on the surface of target cells, primarily in skeletal muscle, adipose tissue, and the liver. When insulin binds to its receptor, it triggers a signaling cascade that promotes the uptake of glucose from the bloodstream into cells, stimulates glycogen synthesis in the liver and muscles, promotes lipogenesis (fat synthesis), and inhibits hepatic gluconeogenesis (the production of new glucose by the liver) and glycogenolysis (the breakdown of stored glycogen to glucose). In diabetes mellitus, this process is impaired either because the pancreas produces insufficient insulin (type 1 diabetes) or because the body’s cells do not respond adequately to insulin (type 2 diabetes), or both.

Insuman Basal SoloStar is indicated for the treatment of diabetes mellitus requiring insulin therapy. This encompasses several clinical scenarios. In type 1 diabetes mellitus, also known as insulin-dependent diabetes, the body’s immune system has destroyed the insulin-producing beta cells, and patients require exogenous insulin replacement for survival. In type 2 diabetes mellitus, Insuman Basal is used when dietary measures, exercise, weight management, and oral antidiabetic medications (such as metformin, sulfonylureas, or SGLT2 inhibitors) have proven insufficient to achieve adequate blood glucose control. It may also be used in gestational diabetes (diabetes during pregnancy) when dietary management alone is insufficient, and in other specific types of diabetes, such as those caused by genetic conditions or pancreatic disease.

As an intermediate-acting insulin, Insuman Basal has distinct pharmacokinetic properties that distinguish it from rapid-acting, short-acting, and long-acting insulins. After subcutaneous injection, the onset of action begins within approximately 60 minutes. The peak hypoglycemic effect occurs between 3 and 4 hours after injection, and the total duration of action is approximately 11 to 20 hours, depending on the dose, injection site, blood flow, temperature, and level of physical activity. This pharmacokinetic profile makes Insuman Basal particularly suitable for providing basal (background) insulin coverage, controlling fasting blood glucose and between-meal glucose levels. The variability in onset and duration is an important clinical consideration, as individual responses to isophane insulin can vary significantly from day to day even within the same patient.

Insuman Basal SoloStar is delivered using the SoloStar pre-filled disposable pen, a well-established insulin delivery device developed by Sanofi. The SoloStar pen contains 3 mL of insulin suspension at a concentration of 100 IU/mL (300 IU total per pen). The dose selector allows patients to dial doses from 1 to 80 units in 1-unit increments, providing flexibility for precise dose titration. The pen features an audible click for each unit dialed, a clear dose window, and a dose confirmation button. This user-friendly design has been shown in studies to be preferred by patients compared with vial-and-syringe injection and is associated with improved adherence to insulin therapy.

Insulin human, including the isophane formulation, has been included on the WHO Model List of Essential Medicines since its inception, recognizing it as one of the most important medications in a basic healthcare system. Despite the development of newer insulin analogues (such as insulin glargine, insulin detemir, and insulin degludec), isophane (NPH) insulin remains a mainstay of diabetes treatment worldwide, particularly in healthcare systems where cost-effectiveness is a primary consideration. International clinical guidelines from the American Diabetes Association (ADA), the European Association for the Study of Diabetes (EASD), and the International Diabetes Federation (IDF) continue to include NPH insulin as an appropriate option for basal insulin therapy in both type 1 and type 2 diabetes.

What Should You Know Before Taking Insuman Basal SoloStar?

Contraindications

The primary contraindication to Insuman Basal SoloStar is hypersensitivity (allergy) to the active substance insulin human or to any of the excipients in the formulation. The excipients include protamine sulfate, metacresol, phenol, zinc chloride, sodium dihydrogen phosphate dihydrate, glycerol, sodium hydroxide, hydrochloric acid, and water for injections. Allergic reactions to insulin can manifest as localized skin reactions at the injection site (redness, swelling, itching) or, rarely, as generalized allergic reactions including urticaria, angioedema, bronchospasm, or anaphylaxis. If you have previously experienced allergic reactions to insulin or protamine, inform your doctor before using Insuman Basal.

Insuman Basal must not be administered intravenously (into a vein). It is designed exclusively for subcutaneous injection. Intravenous administration of isophane insulin suspension could result in unpredictable and potentially dangerous fluctuations in blood glucose levels. Additionally, Insuman Basal must not be used in external or implantable insulin infusion pumps. The suspension formulation can cause blockage of the pump tubing and lead to unreliable insulin delivery. Only clear, soluble insulin preparations should be used in insulin pumps.

Insuman Basal should not be used during episodes of hypoglycemia (low blood sugar). Administration of additional insulin during hypoglycemia would further reduce blood glucose to potentially dangerous levels. If hypoglycemia occurs, the immediate priority is to treat the low blood sugar with glucose (such as glucose tablets, fruit juice, or sugary drinks) and to delay the next insulin injection until blood glucose has returned to a safe level.

Warnings and Precautions

Several medical conditions and circumstances require special attention when using Insuman Basal SoloStar. Discuss the following with your healthcare provider before starting treatment:

• Renal (kidney) impairment: Insulin is partially cleared by the kidneys. In patients with reduced kidney function, insulin requirements may be decreased because insulin elimination is slowed. More frequent blood glucose monitoring and potential dose reduction may be necessary.
• Hepatic (liver) impairment: The liver plays a key role in insulin metabolism and gluconeogenesis. Liver disease can reduce insulin requirements due to impaired gluconeogenesis and reduced insulin degradation capacity. Blood glucose should be monitored closely and doses adjusted accordingly.
• Adrenal, pituitary, or thyroid disorders: Conditions affecting the adrenal glands (such as Addison’s disease), the pituitary gland, or the thyroid gland can alter insulin requirements. Hypothyroidism and adrenal insufficiency may decrease insulin needs, while hyperthyroidism may increase them.
• Illness, surgery, or emotional stress: During acute illness (infections, fever), major surgery, or periods of significant emotional stress, blood glucose levels often rise due to counter-regulatory hormone release (cortisol, glucagon, catecholamines). Insulin requirements may temporarily increase and more frequent blood glucose monitoring is essential.
• Exercise and physical activity: Physical exercise increases glucose uptake by muscles and can lower blood glucose levels. Insulin dose adjustments or additional carbohydrate intake may be needed before, during, or after exercise to prevent hypoglycemia.
• Alcohol consumption: Alcohol inhibits hepatic gluconeogenesis and can potentiate the hypoglycemic effect of insulin. Excessive alcohol intake, particularly without food, increases the risk of severe and prolonged hypoglycemia. Moderate and responsible alcohol consumption with food is recommended.

Pregnancy and Breastfeeding

Insuman Basal SoloStar can be used during pregnancy. Adequate glycemic control is critically important during pregnancy, both for the health of the mother and for the developing fetus. Poorly controlled diabetes during pregnancy increases the risk of congenital malformations, macrosomia (excessively large birth weight), birth complications, neonatal hypoglycemia, and pre-eclampsia. Human insulin does not cross the placenta, making it the preferred insulin type during pregnancy in many clinical guidelines.

Insulin requirements typically change during pregnancy. They may decrease during the first trimester and increase during the second and third trimesters as placental hormones (such as human placental lactogen and progesterone) create increasing insulin resistance. After delivery, insulin requirements usually drop rapidly to pre-pregnancy levels. Frequent blood glucose monitoring and close collaboration with an endocrinologist and obstetrician are essential throughout pregnancy and the postpartum period.

Insuman Basal can be used during breastfeeding. Insulin is a peptide hormone that is degraded in the infant’s gastrointestinal tract and is not absorbed systemically. Therefore, it poses no risk to the breastfed infant. However, breastfeeding mothers with diabetes may require adjustments to their insulin dose and dietary intake, as breastfeeding itself can lower blood glucose levels.

Driving and Operating Machinery

Hypoglycemia can impair your ability to concentrate and react, which is potentially dangerous when driving or operating machinery. Patients should check their blood glucose before driving and at regular intervals during long journeys. Avoid driving if blood glucose is low or if you are unable to recognize warning symptoms of hypoglycemia (a condition known as hypoglycemia unawareness). Keep a source of fast-acting glucose (such as glucose tablets or juice) readily available in the vehicle at all times.

How Does Insuman Basal SoloStar Interact with Other Drugs?

Insulin interacts with a wide range of medications through pharmacodynamic mechanisms that either enhance or reduce its blood glucose lowering effect. Unlike many oral medications, these interactions are not primarily pharmacokinetic (i.e., they do not involve changes in insulin absorption, distribution, or metabolism through CYP enzyme systems). Instead, the interactions occur because many medications independently affect blood glucose levels, and their effects combine with or counteract the glucose-lowering action of insulin. Understanding these interactions is essential for safe and effective insulin therapy.

Substances That May Increase Hypoglycemic Effect

The following medications and substances may enhance the blood glucose lowering effect of insulin, increasing the risk of hypoglycemia. When starting, stopping, or changing the dose of these medications, more frequent blood glucose monitoring and possible insulin dose adjustment may be necessary:

Substances That May Reduce Hypoglycemic Effect

The following medications may weaken the blood glucose lowering effect of insulin, leading to hyperglycemia. Insulin dose increases may be necessary when these medications are initiated or dose-increased:

It is important to inform your doctor, pharmacist, or diabetes nurse about all medications you are taking, including prescription drugs, over-the-counter medicines, herbal supplements, and vitamins. This allows your healthcare team to anticipate potential interactions and adjust your insulin dose proactively. Whenever a new medication is started, stopped, or changed in dose, increased blood glucose monitoring is advisable for several days to detect any impact on glycemic control.

What Is the Correct Dosage of Insuman Basal SoloStar?

Insulin dosing is one of the most individualized aspects of diabetes treatment. Unlike most medications that come with fixed doses, insulin requirements vary enormously between patients and can change over time within the same patient. Factors that influence insulin dose include the type and duration of diabetes, body weight, level of physical activity, dietary intake, degree of insulin resistance, kidney and liver function, other medications, and intercurrent illness. Your doctor will determine your starting dose and provide guidance on how to adjust it based on your blood glucose monitoring results.

Adults

As a general guideline, total daily insulin requirements for adults with diabetes are typically in the range of 0.5 to 1.0 IU per kilogram of body weight per day, although this can vary widely. In type 2 diabetes, patients starting insulin therapy often begin with a lower dose (10 to 20 IU of basal insulin once daily, typically at bedtime) and titrate upward gradually based on fasting blood glucose measurements. In type 1 diabetes, where insulin is the sole treatment, total daily requirements are often 0.4 to 0.8 IU/kg/day, with approximately 40–50% given as basal insulin and the remainder as rapid-acting insulin before meals.

Insuman Basal SoloStar is usually injected subcutaneously 45 to 60 minutes before a meal, although the exact timing depends on the treatment regimen. When used once daily, it is typically administered in the evening (at bedtime) to provide overnight basal coverage and control fasting blood glucose. When used twice daily, it is commonly given before breakfast and before the evening meal or at bedtime. Your doctor will advise on the optimal timing for your specific situation.

The SoloStar pen allows dose selection from 1 to 80 units in 1-unit increments. Before each injection, the pen should be gently rolled between the palms (10 times) and inverted (10 times) to ensure the insulin suspension is uniformly milky white. A safety test (priming) should be performed before each injection by dialing 2 units and pressing the injection button with the needle pointing upward until a drop of insulin appears at the needle tip.

Children and Adolescents

Insuman Basal SoloStar can be used in children and adolescents with diabetes. Insulin requirements in children are highly variable and change with age, growth, puberty, and activity levels. Younger children often have lower total daily insulin requirements per kilogram compared with adolescents, who may experience significantly increased insulin resistance during puberty. Typical insulin requirements during puberty may rise to 1.0–1.5 IU/kg/day or higher. Pediatric insulin therapy should always be supervised by a pediatric endocrinologist or diabetologist with expertise in childhood diabetes.

Elderly Patients

In elderly patients, insulin therapy requires careful consideration. Progressive deterioration of renal function with age may lead to steadily decreasing insulin requirements. Elderly patients may also have reduced ability to recognize hypoglycemia symptoms (hypoglycemia unawareness), reduced cognitive function affecting self-management skills, and other comorbidities that complicate glycemic management. Less stringent glycemic targets may be appropriate in frail elderly patients to minimize the risk of hypoglycemia and its consequences, such as falls and fractures. The ADA recommends individualized HbA1c targets for elderly patients, typically 7.0–8.5% depending on health status and life expectancy.

Missed Dose

If you miss a dose of Insuman Basal SoloStar, check your blood glucose level and administer the dose as soon as you remember, provided it is not too close to your next scheduled dose. Do not inject a double dose to compensate for a forgotten injection. Monitor your blood glucose more frequently after a missed dose, as levels may be higher than usual. If you are unsure about what to do, contact your doctor, diabetes nurse, or pharmacist for guidance. To help avoid missed doses, establish a consistent injection routine and consider using reminders (alarms, apps, or written schedules).

Overdose

An insulin overdose leads to hypoglycemia, which can range from mild (requiring oral glucose intake) to severe (causing loss of consciousness, seizures, or coma). Mild to moderate hypoglycemia can be treated by consuming 15–20 grams of fast-acting carbohydrate (glucose tablets, fruit juice, regular soda, or sugar dissolved in water), waiting 15 minutes, rechecking blood glucose, and repeating if necessary. Severe hypoglycemia, where the patient is unconscious or unable to swallow, is a medical emergency requiring intramuscular or subcutaneous glucagon injection (by a trained caregiver) and/or intravenous glucose administration by medical professionals. Call your local emergency services immediately if severe hypoglycemia occurs. After recovering from severe hypoglycemia, the patient should consume a longer-acting carbohydrate source (bread, crackers, or a meal) to prevent recurrence.

What Are the Side Effects of Insuman Basal SoloStar?

Like all medicines, Insuman Basal SoloStar can cause side effects, although not everybody gets them. The most clinically important adverse effect is hypoglycemia, which can occur if the insulin dose is too high relative to the patient’s glucose intake and energy expenditure. Understanding the full spectrum of potential side effects and knowing how to manage them is essential for safe and effective insulin therapy.

The following side effects are classified according to their frequency, based on data from clinical trials, post-marketing surveillance, and the EMA-approved Summary of Product Characteristics:

Hypoglycemia deserves special emphasis as the most important safety concern with any insulin therapy. Mild hypoglycemia episodes can be treated by the patient themselves through oral glucose intake. Severe hypoglycemia, defined as an episode requiring assistance from another person, can lead to prolonged unconsciousness, seizures, and in extreme cases, death. Risk factors for severe hypoglycemia include intensive insulin therapy with tight glycemic targets, long duration of diabetes, autonomic neuropathy (leading to hypoglycemia unawareness), renal impairment, elderly age, concomitant medications (especially beta-blockers), irregular meal patterns, and alcohol consumption.

Lipodystrophy at injection sites is a preventable complication. Lipohypertrophy (fatty lumps under the skin) develops when insulin is injected repeatedly into the same spot. These lumps can alter insulin absorption, leading to unpredictable blood glucose levels. To prevent lipodystrophy, patients should systematically rotate their injection sites within the same anatomical region and inspect injection areas regularly for any signs of swelling or hardening.

If you experience any side effects, including those not listed here, inform your doctor, diabetes nurse, or pharmacist. Reporting side effects helps regulatory agencies monitor the safety of medications and identify previously unknown adverse reactions.

How Should You Store Insuman Basal SoloStar?

Proper storage of insulin is essential to maintain its effectiveness and safety. Insulin is a protein that can be denatured (destroyed) by extreme temperatures, freezing, and prolonged exposure to light. Incorrect storage can reduce the potency of insulin, leading to inadequate blood glucose control.

Unopened (not yet in use) pens: Store in a refrigerator at 2–8°C (36–46°F). Keep the pens in the outer carton to protect from light. Do not place insulin directly against the freezer compartment or cooling elements – frozen insulin must be discarded as freezing permanently damages the insulin protein structure and the suspension cannot be properly resuspended. Insulin stored correctly in the refrigerator can be used until the expiry date printed on the label and carton.

In-use pens: Once you start using an Insuman Basal SoloStar pen (after the first injection), it should not be stored in the refrigerator. Store it at room temperature, below 25°C (77°F), away from direct heat and direct sunlight. Replace the pen cap after each injection to protect the insulin from light. Do not store the pen with a needle attached, as this can allow air to enter the cartridge or insulin to leak, which may affect dosing accuracy. The in-use pen should be discarded 21 days after first use, even if it still contains insulin.

Before each use: Inspect the insulin visually. Insuman Basal is a suspension that appears milky white when properly resuspended. Before injection, roll the pen gently between your palms (10 times) and invert it (10 times) to mix the suspension uniformly. Do not shake vigorously. Do not use the pen if the suspension remains clear, if clumps, flakes, or particles are visible, or if it has a frosted appearance – these signs indicate that the insulin has been damaged and will not provide reliable glucose-lowering effect.

Keep all medicines out of the sight and reach of children. Do not dispose of insulin pens in household waste. Ask your pharmacist about how to safely dispose of used pens and needles, and always use a sharps disposal container for needles.

What Does Insuman Basal SoloStar Contain?

The active substance in Insuman Basal SoloStar is insulin human, produced by recombinant DNA technology in Escherichia coli. Each milliliter of suspension contains 100 IU (International Units) of insulin human, equivalent to approximately 3.5 mg. Each SoloStar pre-filled pen contains 3 mL of suspension, providing a total of 300 IU of insulin per pen.

The insulin human in Insuman Basal is formulated as isophane (NPH) insulin. In this formulation, the insulin is combined with protamine sulfate (a positively charged protein derived from fish sperm) and zinc chloride to form crystalline particles that are suspended in the solution. This crystalline complex is responsible for the intermediate duration of action, as it delays the release and absorption of insulin from the subcutaneous tissue after injection.

The other ingredients (excipients) in Insuman Basal SoloStar are:

• Protamine sulfate: Forms the isophane complex with insulin, providing the intermediate-acting profile.
• Metacresol: An antimicrobial preservative that prevents bacterial contamination of the multi-dose pen.
• Phenol: An additional antimicrobial preservative.
• Zinc chloride: Stabilizes the insulin-protamine complex and contributes to the formation of insulin hexamers.
• Sodium dihydrogen phosphate dihydrate: A buffering agent that maintains the pH of the suspension.
• Glycerol: An isotonicity agent that ensures the suspension is isotonic with body fluids.
• Sodium hydroxide: Used for pH adjustment during manufacturing.
• Hydrochloric acid: Used for pH adjustment during manufacturing.
• Water for injections: The vehicle (solvent) for the suspension.

Insuman Basal SoloStar contains less than 1 mmol (23 mg) sodium per dose, meaning it is essentially sodium-free. This is relevant for patients on a sodium-restricted diet. Patients with a known allergy to protamine (found in certain medications, including protamine used to reverse heparin anticoagulation) should inform their doctor, as cross-reactivity is theoretically possible, although rarely clinically significant.

The appearance of Insuman Basal suspension is a milky white liquid when properly resuspended. After standing, the suspension will separate into a clear supernatant and a white deposit. This is normal and expected – the pen must be gently mixed before each injection to restore uniform suspension. The pH of the formulation is approximately 7.0 (neutral), and the suspension is formulated to be isotonic with body fluids for comfortable injection.