Insuman Rapid SoloStar: Uses, Dosage & Side Effects
A fast-acting human insulin (regular insulin) in a pre-filled pen for the treatment of diabetes mellitus requiring insulin therapy
Insuman Rapid SoloStar is a fast-acting human insulin preparation delivered via a disposable pre-filled injection pen (SoloStar). It contains recombinant human insulin (regular, soluble insulin) at a concentration of 100 IU/mL and is indicated for the treatment of diabetes mellitus in patients who require insulin therapy. As a short-acting insulin, Insuman Rapid is primarily used to control blood sugar levels around mealtimes (prandial insulin coverage). It should be injected subcutaneously 15–20 minutes before meals. When used as part of a basal-bolus insulin regimen, Insuman Rapid is combined with an intermediate- or long-acting insulin to provide comprehensive blood glucose control throughout the day and night. Insulin human is listed on the WHO Model List of Essential Medicines, underscoring its fundamental importance in diabetes care worldwide.
Quick Facts: Insuman Rapid SoloStar
Key Takeaways
- Insuman Rapid SoloStar contains recombinant human insulin (regular/soluble insulin) and is used as a mealtime insulin for both type 1 and type 2 diabetes when insulin therapy is required.
- It has a rapid onset (within 30 minutes), peak effect at 1–4 hours, and duration of 7–9 hours, making it suitable for pre-meal injection 15–20 minutes before eating.
- Hypoglycemia (low blood sugar) is the most common side effect — patients must learn to recognize symptoms and always carry fast-acting glucose.
- The SoloStar pen is a convenient, disposable device that allows dose adjustment from 1 to 80 units in 1-unit increments, and must never be shared between patients even with a new needle.
- Insulin human is on the WHO Model List of Essential Medicines, reflecting its critical role as one of the most widely used and well-studied diabetes medications globally.
What Is Insuman Rapid SoloStar and What Is It Used For?
Insuman Rapid SoloStar contains insulin human as its active substance. Insulin human is a peptide hormone that is structurally identical to the insulin naturally produced by the beta cells of the pancreatic islets of Langerhans in the human body. The insulin in Insuman Rapid is produced using recombinant DNA technology (rDNA) in Escherichia coli bacteria, followed by purification and formulation to produce a clear, colorless, aqueous solution suitable for injection. This method of production ensures a high degree of purity and consistency, with the resulting insulin molecule being chemically and biologically identical to endogenous human insulin.
Insulin is essential for life. It is the primary hormone responsible for regulating blood glucose levels by facilitating the uptake of glucose from the bloodstream into cells — primarily skeletal muscle cells, adipose (fat) tissue, and liver cells. In people with diabetes mellitus, the body either does not produce enough insulin (type 1 diabetes, where the immune system destroys the insulin-producing beta cells) or cannot use the insulin it produces effectively (type 2 diabetes, characterized by insulin resistance and progressive beta cell dysfunction). Without adequate insulin, glucose accumulates in the blood (hyperglycemia), which over time can lead to serious complications including cardiovascular disease, kidney disease (diabetic nephropathy), nerve damage (diabetic neuropathy), and vision loss (diabetic retinopathy).
As a regular (soluble) insulin, Insuman Rapid belongs to the category of fast-acting insulins. After subcutaneous injection, it begins to lower blood glucose within approximately 30 minutes, reaches its maximum glucose-lowering effect between 1 and 4 hours, and has an overall duration of action of approximately 7 to 9 hours. This pharmacokinetic profile makes it ideally suited for use as a prandial (mealtime) insulin, injected shortly before meals to manage the postprandial (after-meal) rise in blood glucose that occurs as food is digested and carbohydrates are absorbed into the bloodstream.
Insuman Rapid SoloStar is indicated for the treatment of diabetes mellitus in patients who require insulin therapy. This includes patients with type 1 diabetes mellitus, who have an absolute requirement for exogenous insulin because their pancreas produces little or no insulin; patients with type 2 diabetes mellitus in whom oral antidiabetic medications and lifestyle modifications alone are no longer sufficient to achieve adequate blood glucose control; gestational diabetes (diabetes during pregnancy) when dietary management alone is insufficient; and diabetic ketoacidosis and diabetic coma, where insulin is a critical component of emergency treatment (typically administered intravenously in these acute settings).
The SoloStar pen is a disposable, pre-filled injection device designed for ease of use and accurate dosing. Each pen contains 3 mL of insulin solution (300 IU total) and allows dose selection from 1 to 80 units in increments of 1 unit. The pen features a dose window with clear markings, an audible click mechanism during dose dialing, and a smooth injection button. Patients use the pen with compatible pen needles (not included) and should follow their healthcare provider's instructions for proper injection technique, including rotating injection sites to reduce the risk of lipodystrophy (changes in fat tissue at the injection site).
Human insulin has been included on the World Health Organization (WHO) Model List of Essential Medicines since its inception, recognizing it as one of the most important medications needed in a basic healthcare system. Approximately 537 million adults worldwide live with diabetes (International Diabetes Federation, 2021), and access to affordable insulin remains a critical global health priority. Regular human insulin like Insuman Rapid continues to play a vital role in diabetes care, particularly in settings where newer insulin analogues may not be available or affordable.
What Should You Know Before Taking Insuman Rapid SoloStar?
Contraindications
Insuman Rapid SoloStar must not be used in the following situations. First, it is contraindicated in patients who are experiencing hypoglycemia (low blood sugar). Administering insulin during an episode of hypoglycemia would further lower blood glucose to dangerous or even life-threatening levels. Second, it must not be used by anyone who is allergic (hypersensitive) to insulin human or to any of the other ingredients contained in the formulation. The excipients in Insuman Rapid include metacresol (a preservative), sodium dihydrogen phosphate dihydrate, glycerol, sodium hydroxide, hydrochloric acid, and water for injections. If you have a known allergy to any of these substances, inform your doctor before starting treatment.
Additionally, Insuman Rapid SoloStar must not be used in insulin infusion pumps. It is formulated specifically for subcutaneous injection via the SoloStar pen device or, in clinical settings, for intravenous administration from vials. Certain insulin pumps have specific insulin compatibility requirements, and Insuman Rapid is not approved for this route of administration in the pre-filled pen format.
Warnings and Precautions
Insuman Rapid SoloStar pens must never be shared between patients, even if the needle is changed. Sharing pens carries a risk of cross-contamination and transmission of blood-borne infections. Each SoloStar pen is for single-patient use only.
Before starting treatment with Insuman Rapid SoloStar, and during insulin therapy, discuss the following important considerations with your healthcare provider:
- Hypoglycemia awareness: Hypoglycemia (low blood sugar) is the most frequent adverse effect of insulin therapy. You must learn to recognize the early warning signs of hypoglycemia, which include sweating, trembling, hunger, rapid heartbeat, tingling in the lips or fingers, pallor, headache, and difficulty concentrating. If left untreated, hypoglycemia can progress to confusion, loss of consciousness, seizures, and in rare cases, death. Always carry a fast-acting source of glucose (such as glucose tablets, sugar cubes, or fruit juice) and ensure that family members, friends, and colleagues know how to help you in case of a severe hypoglycemic episode.
- Changing insulin type or brand: If your doctor switches you from one type of insulin to another (for example, from an insulin analogue to human insulin, or between different brands of human insulin), your dose may need to be adjusted. A change in insulin concentration, manufacturer, type (regular, NPH, long-acting), origin (animal, human, analogue), or method of manufacture may require a dose change. Your doctor will guide you through any transition period.
- Liver or kidney disease: Patients with impaired liver or kidney function may have reduced insulin requirements because insulin clearance is partially dependent on hepatic and renal metabolism. Careful blood glucose monitoring is essential in these patients to avoid hypoglycemia, and dose adjustments may be necessary.
- Illness and stress: During illness (especially infections with fever), emotional stress, or other acute situations, insulin requirements typically increase. Conversely, reduced food intake (for example, due to nausea or vomiting) may necessitate a reduction in insulin dose. Monitor blood glucose more frequently during illness and adjust doses according to your doctor's guidance. Never stop insulin completely during illness, especially in type 1 diabetes, as this can lead to diabetic ketoacidosis.
- Travel: If you are traveling across time zones, consult your doctor before your trip about how to adjust your insulin schedule. Carry sufficient insulin supplies, glucose monitoring equipment, and fast-acting glucose. Keep insulin in appropriate storage conditions (avoid freezing and excessive heat) during travel.
- Thiazolidinediones (glitazones): Combination of insulin with pioglitazone or other thiazolidinediones has been associated with an increased risk of heart failure, particularly in patients with pre-existing cardiac risk factors. Report any symptoms such as unusual weight gain, shortness of breath, or ankle swelling to your doctor immediately.
Pregnancy and Breastfeeding
If you are pregnant, think you may be pregnant, or are planning to become pregnant, inform your doctor. Insulin requirements typically change during pregnancy. In the first trimester, insulin requirements often decrease, while in the second and third trimesters, requirements usually increase. After delivery, insulin requirements typically return to pre-pregnancy levels relatively quickly. Careful blood glucose monitoring and frequent dose adjustments are essential throughout pregnancy to protect both mother and baby.
Human insulin does not cross the placenta in significant amounts, and insulin human is considered the standard of care for the management of diabetes in pregnancy when insulin therapy is required. Both the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) support the use of human insulin during pregnancy.
If you are breastfeeding, your insulin dose and diet may need adjustment. Insulin is not absorbed from the gastrointestinal tract and poses no risk to the nursing infant. However, breastfeeding may affect your blood glucose levels and insulin requirements, so monitoring and dose adjustment remain important.
Children and Adolescents
Insuman Rapid SoloStar can be used in children and adolescents aged 6 years and older. In children younger than 6 years, clinical data with Insuman Rapid are limited, and your doctor will determine the most appropriate insulin treatment for younger children. The dose of insulin in children is individualized based on body weight, blood glucose levels, diet, and physical activity. Close monitoring by a pediatric diabetes team is essential, as insulin requirements can change rapidly during growth and puberty.
Driving and Operating Machinery
Hypoglycemia can impair your concentration and reaction time, which can be dangerous when driving or operating machinery. You should take special precautions to avoid hypoglycemia while driving, especially if you have reduced or absent awareness of hypoglycemic warning signs (hypoglycemia unawareness). Check your blood glucose level before driving and at regular intervals during long journeys. Keep fast-acting glucose readily available in your vehicle. If you feel hypoglycemic symptoms, stop driving safely, treat the hypoglycemia, and do not resume driving until your blood glucose has returned to normal and you are fully alert.
How Does Insuman Rapid SoloStar Interact with Other Drugs?
Insulin interacts with a wide range of medications, and these interactions can either enhance or diminish the blood glucose-lowering effect of insulin. Understanding these interactions is critical for safe and effective diabetes management. Unlike many oral medications, insulin's interactions are primarily pharmacodynamic (affecting the body's response to insulin or glucose metabolism) rather than pharmacokinetic (affecting how insulin is absorbed, distributed, metabolized, or excreted). This is because insulin is a peptide hormone that is not metabolized by cytochrome P450 (CYP) enzymes in the liver.
The following table summarizes the most clinically important drug interactions with Insuman Rapid SoloStar:
| Drug / Drug Class | Effect on Blood Glucose | Clinical Significance |
|---|---|---|
| Oral antidiabetic agents (metformin, sulfonylureas, SGLT2 inhibitors) | Increased hypoglycemia risk | Dose adjustment of insulin may be required; monitor blood glucose closely |
| ACE inhibitors (enalapril, ramipril, lisinopril) | Increased hypoglycemia risk | May enhance insulin sensitivity; monitor blood glucose when starting or stopping |
| MAO inhibitors (selegiline, moclobemide) | Increased hypoglycemia risk | Significant increase in insulin effect; close monitoring essential |
| Salicylates (high-dose aspirin) | Increased hypoglycemia risk | High doses may increase insulin effect; low-dose aspirin has minimal effect |
| Corticosteroids (prednisolone, dexamethasone) | Decreased insulin effect (hyperglycemia) | Often requires significant insulin dose increase; monitor closely |
| Thyroid hormones (levothyroxine) | Decreased insulin effect (hyperglycemia) | May increase insulin requirements; adjust dose when thyroid status changes |
| Thiazide diuretics (hydrochlorothiazide) | Decreased insulin effect (hyperglycemia) | May raise blood glucose; monitor and adjust insulin dose |
| Beta-blockers (propranolol, metoprolol, atenolol) | Variable; may mask hypoglycemia symptoms | Can mask tachycardia and tremor of hypoglycemia; sweating is not masked. Non-selective beta-blockers have greater effect |
| Sympathomimetics (epinephrine, salbutamol, terbutaline) | Decreased insulin effect (hyperglycemia) | May raise blood glucose; monitor during concurrent use |
| Octreotide / Lanreotide (somatostatin analogues) | Variable (may increase or decrease) | May reduce or increase insulin requirements; close monitoring needed |
| Alcohol | Variable; may increase or prolong hypoglycemia | Alcohol inhibits hepatic gluconeogenesis; can cause delayed and prolonged hypoglycemia. Never drink alcohol on an empty stomach |
Drugs That Increase Hypoglycemia Risk
Several classes of medications can enhance the blood glucose-lowering effect of insulin, thereby increasing the risk of hypoglycemia. These include oral antidiabetic agents (particularly sulfonylureas and meglitinides, which stimulate endogenous insulin secretion), angiotensin-converting enzyme (ACE) inhibitors, monoamine oxidase (MAO) inhibitors, fibrates (such as fenofibrate and gemfibrozil), fluoxetine, pentoxifylline, propoxyphene, and high-dose salicylates. When any of these medications are started, stopped, or have their dose adjusted, increased blood glucose monitoring is recommended and insulin dose adjustments may be necessary.
Drugs That May Reduce Insulin Effect
Other medications can counteract insulin's effect and raise blood glucose levels, potentially necessitating an increase in insulin dose. These include corticosteroids (one of the most clinically significant interactions), thyroid hormones, growth hormone, danazol, diazoxide, sympathomimetic agents (such as epinephrine, salbutamol, and terbutaline), thiazide diuretics, oral contraceptives, phenothiazines, and protease inhibitors used in HIV treatment. Patients starting or stopping these medications should monitor blood glucose more frequently and adjust their insulin dose in consultation with their healthcare provider.
Alcohol and Insulin
Alcohol requires special mention due to its complex and potentially dangerous interaction with insulin. Moderate alcohol consumption can acutely enhance insulin's glucose-lowering effect, while chronic heavy alcohol use may reduce it. The most dangerous scenario occurs when alcohol is consumed without food, as alcohol inhibits hepatic gluconeogenesis (the liver's ability to produce glucose), which can lead to severe, prolonged, and difficult-to-treat hypoglycemia. This effect can persist for many hours after alcohol consumption, including overnight. Patients using insulin should be advised to always consume food when drinking alcohol, to moderate their alcohol intake, and to check blood glucose levels before going to sleep after drinking.
Beta-blockers, particularly non-selective agents like propranolol, can mask some of the typical warning signs of hypoglycemia, specifically rapid heartbeat (tachycardia) and tremor. However, sweating — an important hypoglycemic symptom — is not masked by beta-blockers. Patients taking beta-blockers alongside insulin should be educated about this interaction and advised to rely on sweating and other non-adrenergic symptoms (such as hunger and difficulty concentrating) as warning signs of low blood sugar.
What Is the Correct Dosage of Insuman Rapid SoloStar?
Insulin dosing in diabetes is one of the most individualized aspects of medical treatment. The dose of Insuman Rapid SoloStar is determined by your doctor based on a comprehensive assessment of your blood glucose levels, type of diabetes, body weight, dietary habits, physical activity level, concurrent medications, and overall metabolic status. There is no single "standard" dose that applies to all patients. The goal of insulin therapy is to maintain blood glucose levels as close to normal as possible while minimizing the risk of hypoglycemia.
Adults
Typical Adult Dosing Guidelines
As a general reference, total daily insulin requirements in adults typically range from 0.5 to 1.0 IU per kilogram of body weight per day. In a basal-bolus regimen, approximately 40–60% of the total daily dose is given as basal (long-acting) insulin, and the remaining 40–60% is divided among mealtime (bolus) injections with a fast-acting insulin like Insuman Rapid. For example, a 70 kg adult might require approximately 35–70 IU of total insulin per day, with approximately 12–25 IU given as Insuman Rapid divided across three meals.
Insuman Rapid SoloStar should be injected subcutaneously approximately 15 to 20 minutes before a meal. The injection should be given into the abdominal wall, thigh, upper arm, or buttock. Injection sites should be rotated within the same anatomical region to reduce the risk of lipodystrophy (lumps or pitting of the fatty tissue under the skin). Absorption of insulin is generally fastest from the abdominal wall, followed by the thigh, upper arm, and buttock.
| Patient Group | Typical Dose Range | Key Considerations |
|---|---|---|
| Adults (Type 1) | 0.5–1.0 IU/kg/day total; bolus portion divided across meals | Requires basal insulin; carbohydrate counting often used for dose calculation |
| Adults (Type 2) | Variable; may start at 4 IU per meal and titrate | Often added to basal insulin when HbA1c targets not met; may be used with oral agents |
| Children (≥6 years) | Individualized; typically 0.5–1.5 IU/kg/day total | Requirements change with growth and puberty; close monitoring by pediatric team |
| Elderly | Usually lower; start conservatively | Higher risk of hypoglycemia; reduced renal/hepatic clearance; less stringent HbA1c targets may be appropriate |
| Renal impairment | Reduced dose often needed | Insulin clearance is decreased; frequent monitoring required |
| Hepatic impairment | Reduced dose often needed | Gluconeogenesis may be impaired, increasing hypoglycemia risk |
Children
In children aged 6 years and older, Insuman Rapid SoloStar is dosed on an individual basis, just as in adults. Children with type 1 diabetes typically require total daily insulin doses of 0.5 to 1.5 IU/kg/day, with higher requirements often seen during puberty due to hormonal changes that increase insulin resistance. The mealtime bolus dose should be adjusted based on the carbohydrate content of each meal, the child's pre-meal blood glucose level, and anticipated physical activity. Pediatric diabetes teams often teach families carbohydrate counting and correction factor calculations to enable precise dose adjustments.
Elderly
In elderly patients, insulin therapy should be initiated cautiously and at lower doses. Elderly individuals may have reduced renal and hepatic function, which decreases insulin clearance and prolongs its action. They are also at higher risk for severe hypoglycemia and its consequences, including falls, confusion, and cardiovascular events. Current guidelines from the ADA recommend less stringent glycemic targets (HbA1c < 8.0% or even < 8.5%) for elderly patients with limited life expectancy, significant comorbidities, or frequent hypoglycemia, rather than aggressively targeting normal blood glucose levels.
Missed Dose
If you forget to inject Insuman Rapid SoloStar before a meal, do not attempt to make up for the missed dose by injecting a double dose at your next meal. Instead, check your blood glucose level. If you realize the missed dose relatively soon after the meal, you may inject a smaller dose (consult your doctor for specific guidance). If considerable time has passed, monitor your blood glucose and manage any hyperglycemia according to your doctor's instructions. Record the missed dose and inform your healthcare team at your next visit. Frequent missed doses should be discussed with your doctor, as they may indicate a need to simplify your insulin regimen.
Overdose
An overdose of insulin causes hypoglycemia, which can be life-threatening. Mild to moderate hypoglycemia should be treated immediately with fast-acting oral carbohydrates (glucose tablets, fruit juice, sugary drink). Severe hypoglycemia with loss of consciousness requires administration of glucagon (intramuscular or subcutaneous injection by a trained person) and immediate emergency medical attention. Intravenous glucose may be administered in hospital. After recovery from severe hypoglycemia, a carbohydrate-rich snack or meal should be consumed to prevent recurrence, and blood glucose should be monitored closely for several hours.
There is no specific defined overdose threshold for insulin because the appropriate dose varies widely between patients. However, any dose that is significantly higher than your prescribed dose places you at risk of hypoglycemia. If you suspect you have accidentally administered too much insulin, take the following steps: immediately consume fast-acting carbohydrates (15–20 grams of glucose), check your blood glucose level within 15 minutes, repeat carbohydrate intake if blood glucose remains low, and contact your healthcare provider or emergency services if symptoms do not improve or are severe. Ensure that your family members and close contacts know how to administer glucagon and when to call emergency services.
What Are the Side Effects of Insuman Rapid SoloStar?
Like all medicines, Insuman Rapid SoloStar can cause side effects, although not everybody gets them. The most important and most common adverse effect is hypoglycemia, which results from the fundamental pharmacological action of insulin (lowering blood glucose). The frequency and severity of hypoglycemia depend on the insulin dose, timing of meals, physical activity, and other medications being used. Proper patient education, regular blood glucose monitoring, and dose adjustment are key to minimizing this risk.
The side effects of Insuman Rapid SoloStar are classified below by frequency, using the standard medical convention:
Very Common
May affect more than 1 in 10 people
- Hypoglycemia: Sweating, trembling, hunger, rapid heartbeat (palpitations), tingling in lips/fingers, pallor, headache, difficulty concentrating, confusion, drowsiness. Severe cases may cause loss of consciousness, seizures, and can be life-threatening if untreated.
Common
May affect up to 1 in 10 people
- Injection site reactions: Redness, swelling, itching, pain, or hardening at the injection site. Usually mild and transient. Rotate injection sites to minimize occurrence.
- Lipodystrophy at injection site: Fatty lumps (lipohypertrophy) or pitting/thinning of fatty tissue (lipoatrophy) where injections are given repeatedly in the same spot. Rotate injection sites consistently to prevent this.
- Edema: Mild fluid retention (swelling of ankles or feet), particularly when starting insulin therapy or during intensification of treatment. Usually resolves on its own.
Uncommon
May affect up to 1 in 100 people
- Urticaria (hives): Itchy, raised welts on the skin that may indicate a mild allergic reaction.
- Mild allergic reactions: Skin rash, pruritus (itching), or localized swelling at or near the injection site.
Rare
May affect up to 1 in 1,000 people
- Severe allergic reactions (anaphylaxis): Generalized skin rash, angioedema (swelling of face, tongue, or throat), difficulty breathing, rapid drop in blood pressure, and potentially life-threatening anaphylactic shock. Requires immediate emergency medical treatment.
- Severe hypokalemia: Insulin drives potassium into cells, which can lower blood potassium levels. Severe hypokalemia can cause muscle weakness, muscle cramps, and cardiac arrhythmias. This risk is higher when insulin is used at high doses or in combination with other drugs that lower potassium.
Not Known
Frequency cannot be estimated from available data
- Visual disturbances: Temporary blurred vision may occur when starting insulin therapy or during significant changes in blood glucose control. This is usually due to changes in the refractive properties of the lens and resolves without treatment within a few weeks.
- Sodium retention: Insulin may cause sodium retention, which can contribute to fluid accumulation and may be relevant in patients with heart failure or hypertension.
If you experience any serious side effects, or if you notice any side effects not listed above, contact your doctor or pharmacist. In the EU, you can also report side effects to your national pharmacovigilance agency. Reporting side effects helps provide more information on the safety of this medicine.
To reduce the risk of hypoglycemia while using Insuman Rapid SoloStar: (1) Always eat a meal within 15–20 minutes of injection; (2) Monitor blood glucose regularly, especially before meals and at bedtime; (3) Be aware that physical exercise can increase insulin sensitivity and lower blood glucose for many hours afterward; (4) Always carry fast-acting glucose; (5) Inform family, friends, and colleagues about your diabetes and teach them how to recognize and treat hypoglycemia; (6) Consider wearing a medical identification bracelet or necklace.
How Should You Store Insuman Rapid SoloStar?
Proper storage of insulin is essential to maintaining its effectiveness and safety. Insulin that has been exposed to extreme temperatures (freezing or excessive heat), direct sunlight, or that has been stored beyond its expiry date or in-use period may lose potency, potentially leading to inadequate blood glucose control.
Unopened Pens (Not Yet in Use)
Insuman Rapid SoloStar pens that have not yet been opened should be stored in a refrigerator at 2°C to 8°C (36°F to 46°F). Place them in the body of the refrigerator, away from the freezer compartment and the walls of the refrigerator, where temperatures can fluctuate. Do not freeze Insuman Rapid SoloStar. If insulin has been accidentally frozen, it must be discarded. Frozen insulin may contain aggregated or denatured protein particles that reduce its effectiveness and could potentially cause injection site reactions.
In-Use Pens (After First Use)
Once you begin using an Insuman Rapid SoloStar pen, it can be kept at room temperature (up to 25°C / 77°F) for a maximum of 4 weeks (28 days). Do not refrigerate the pen after first use, as cold insulin can be uncomfortable to inject and may affect absorption. Keep the pen cap on when not in use to protect the solution from light. After 4 weeks, discard the pen even if it still contains insulin, as the preservative (metacresol) may not maintain sterility beyond this period.
Visual Inspection
Before each injection, visually inspect the insulin. Insuman Rapid should be a clear, colorless solution with no visible particles. If the solution appears cloudy, discolored, or contains any particles or flakes, do not use it and obtain a new pen. Also check the expiry date printed on the pen — do not use insulin that has passed its expiry date.
Disposal
Do not throw away used pens in household waste. Dispose of used pens and needles in an appropriate sharps container according to your local regulations. Ask your pharmacist about how to dispose of medicines and sharps containers properly. These measures help protect people and the environment.
When traveling, carry your insulin in a cool bag or insulated case to protect it from extreme temperatures. Avoid leaving insulin in a car (which can become very hot or cold), in direct sunlight, or in checked luggage on flights (where temperatures in the cargo hold can drop below freezing). Carry a letter from your doctor confirming your need for insulin and injection supplies, particularly when traveling by air.
What Does Insuman Rapid SoloStar Contain?
Active Substance
The active substance in Insuman Rapid SoloStar is insulin human, produced using recombinant DNA (rDNA) technology in Escherichia coli. Each milliliter of solution contains 100 International Units (IU), equivalent to 3.5 mg of insulin human. Each pre-filled SoloStar pen contains 3 mL of solution, providing a total of 300 IU of insulin per pen. Insulin human is a 51-amino acid peptide hormone consisting of two polypeptide chains (A-chain with 21 amino acids and B-chain with 30 amino acids) connected by two disulfide bridges, identical in structure to naturally produced human insulin.
Inactive Ingredients (Excipients)
| Excipient | Function |
|---|---|
| Metacresol | Antimicrobial preservative; maintains sterility during the 4-week in-use period |
| Sodium dihydrogen phosphate dihydrate | Buffer; helps maintain the pH of the solution within the required range |
| Glycerol | Tonicity agent; makes the solution isotonic with body fluids for comfortable injection |
| Sodium hydroxide | pH adjuster; used during manufacturing to achieve the correct pH |
| Hydrochloric acid | pH adjuster; used during manufacturing to achieve the correct pH |
| Water for injections | Solvent; provides the aqueous base for the solution |
Insuman Rapid SoloStar does not contain zinc (unlike some other insulin formulations) or protamine. The absence of these additives is what gives it its clear appearance and rapid onset of action, distinguishing it from intermediate-acting NPH insulin preparations (such as Insuman Basal), which contain protamine and appear cloudy. The solution has a pH of approximately 7.0 (neutral), making it suitable for both subcutaneous and intravenous administration.
Description and Packaging
Insuman Rapid SoloStar is a clear, colorless, aqueous solution for injection. It is supplied in 3 mL glass cartridges sealed into disposable SoloStar pre-filled pens. Each pen is fitted with a plunger and a dose-selection mechanism that allows doses from 1 to 80 IU in 1-unit steps. Pens are available in packs of 3, 4, 5, 6, 9, or 10 pens, though not all pack sizes may be marketed in every country. Pen needles are not included and must be purchased separately.
Frequently Asked Questions About Insuman Rapid SoloStar
Insuman Rapid SoloStar is a fast-acting human insulin used to treat diabetes mellitus in adults, adolescents, and children aged 6 years and older who require insulin therapy. It is used to control blood sugar levels around mealtimes (prandial insulin) and is typically injected 15–20 minutes before a meal. It is suitable for both type 1 and type 2 diabetes when insulin therapy is needed, and is also used in the acute management of diabetic ketoacidosis and diabetic coma (intravenous route in hospital).
After subcutaneous injection, Insuman Rapid SoloStar begins to lower blood glucose within approximately 30 minutes. It reaches its peak effect between 1 and 4 hours after injection, and its glucose-lowering effect lasts for 7 to 9 hours. This is why it should be injected 15–20 minutes before meals, allowing the insulin to start working as food is digested and blood sugar begins to rise. When given intravenously (in hospital settings), the onset of action is almost immediate.
Hypoglycemia (low blood sugar) is the most common and potentially most serious side effect. Symptoms include sweating, trembling, hunger, rapid heartbeat, confusion, dizziness, and in severe cases, loss of consciousness or seizures. Injection site reactions such as redness, swelling, itching, or pain are also common. Proper dose adjustment, regular blood glucose monitoring, and consistent meal timing help minimize these risks.
The pre-filled SoloStar pen must not be mixed with any other insulin or medicinal product. The pen is designed for single-product use only and cannot be refilled. However, when using Insuman Rapid from a vial with a syringe, your doctor may instruct you to mix it with Insuman Basal (NPH insulin) in the same syringe. Always draw up the clear Insuman Rapid first, then the cloudy Insuman Basal. Never mix insulins from different manufacturers, as compatibility has not been established.
If you accidentally inject too much Insuman Rapid SoloStar, you are at risk of hypoglycemia. Immediately consume fast-acting carbohydrates such as glucose tablets, sugar cubes, fruit juice, or a sugary drink. Check your blood glucose frequently and eat a carbohydrate-rich snack or meal. If hypoglycemia is severe and you lose consciousness, someone should administer a glucagon injection and call emergency services. Never inject more insulin to compensate. Always carry glucose tablets and ensure those around you know how to help in an emergency.
Unopened pens should be stored in a refrigerator at 2–8°C. Do not freeze. Once in use, the pen can be kept at room temperature (up to 25°C) for a maximum of 4 weeks, protected from direct heat and light. After 4 weeks, discard the pen even if it still contains insulin. Always inspect the solution before use — it should be clear and colorless with no visible particles. If it appears cloudy or discolored, do not use it.
References
- European Medicines Agency (EMA). Insuman Rapid SoloStar – Summary of Product Characteristics (SmPC). Last updated 2024. Available from: EMA product database.
- American Diabetes Association (ADA). Standards of Care in Diabetes – 2025. Diabetes Care. 2025;48(Suppl 1):S1–S352.
- Davies MJ, Aroda VR, Collins BS, et al. Management of Hyperglycemia in Type 2 Diabetes, 2022. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetes Care. 2022;45(11):2753–2786.
- World Health Organization (WHO). WHO Model List of Essential Medicines – 23rd List (2023). Geneva: WHO; 2023.
- International Diabetes Federation (IDF). IDF Diabetes Atlas, 10th Edition. Brussels: IDF; 2021.
- National Institute for Health and Care Excellence (NICE). Type 1 Diabetes in Adults: Diagnosis and Management (NG17). Updated 2022.
- National Institute for Health and Care Excellence (NICE). Type 2 Diabetes in Adults: Management (NG28). Updated 2022.
- Holt RIG, DeVries JH, Hess-Fischl A, et al. The management of type 1 diabetes in adults. A consensus report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetologia. 2021;64(12):2609–2652.
- British National Formulary (BNF). Insulin (human). National Institute for Health and Care Excellence. Accessed December 2025.
- Sanofi. SoloStar Pre-filled Insulin Pen – Instructions for Use. Patient information leaflet. 2024.
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