Every Medication Has Side Effects — Here's What to Know About Afrezza

Afrezza is an inhaled insulin used to control blood sugar in adults with type 1 or type 2 diabetes. Because it's delivered through the lungs instead of an injection, it has a unique side-effect profile compared to traditional injectable insulins. Some side effects are mild and temporary. Others are serious and require immediate medical attention.

This guide breaks down exactly what to expect — using data from Afrezza's FDA-approved labeling — so you can make informed decisions with your doctor.

What Is Afrezza? (Brief Overview)

Afrezza (insulin human inhalation powder) is an ultra rapid-acting inhaled insulin made by MannKind Corporation. It uses Technosphere technology — insulin adsorbed onto tiny microparticles that dissolve rapidly in the deep lung, delivering insulin into your bloodstream within about 12 minutes. It's taken at the beginning of each meal using a small handheld inhaler.

For a full breakdown of how it works, see our guide: How Does Afrezza Work? Mechanism of Action Explained.

Common Side Effects

These side effects were reported frequently in clinical trials and are generally mild:

• Hypoglycemia (low blood sugar) — The most common side effect of any insulin. Symptoms include shakiness, sweating, fast heartbeat, dizziness, and confusion. This risk increases if you take too much Afrezza, skip meals, or exercise more than usual.
• Cough — This is the most distinctive Afrezza side effect. A dry, non-productive cough typically occurs within minutes of inhalation. In clinical trials, cough affected about 25-30% of patients. It usually decreases over time as your body adjusts.
• Sore throat or throat irritation — Mild throat discomfort is common in the first few weeks. Drinking water after inhalation can help.

For most patients, these side effects improve within the first few weeks of use. If cough or throat irritation persists or gets worse, let your doctor know.

Serious Side Effects

These are less common but require medical attention:

• Acute bronchospasm — This is the subject of Afrezza's boxed warning, the FDA's most serious safety alert. Bronchospasm means sudden tightening of the muscles around your airways, causing wheezing, chest tightness, and difficulty breathing. This risk is highest in patients with chronic lung disease like asthma or COPD — which is why Afrezza is contraindicated (not allowed) in those patients.
• Decline in pulmonary function (FEV1) — Afrezza can cause a small, progressive decline in lung function over time. This is why the FDA requires spirometry testing before you start, at 6 months, and annually. If your FEV1 drops by 20% or more, your doctor may discontinue Afrezza.
• Diabetic ketoacidosis (DKA) — Afrezza alone is not sufficient for patients with type 1 diabetes — they must also use a long-acting basal insulin. Stopping basal insulin or relying solely on Afrezza can lead to DKA, a dangerous buildup of acids in the blood.
• Severe hypoglycemia — In rare cases, blood sugar can drop dangerously low, leading to seizures, loss of consciousness, or death. This is more likely if doses are not adjusted properly or if Afrezza is combined with other blood-sugar-lowering medications.
• Hypokalemia (low potassium) — Insulin drives potassium into cells, which can lower blood potassium levels. Severe hypokalemia can cause muscle weakness, cramps, and heart rhythm problems.
• Hypersensitivity reactions — Rarely, patients may experience allergic reactions including rash, swelling, or difficulty breathing.
• Lung cancer — In clinical trials, a slightly higher incidence of lung cancer was observed in Afrezza-treated patients compared to controls. A causal relationship has not been established, but patients with a history of lung cancer should discuss this with their doctor.

Specific Populations

Smokers and Recent Ex-Smokers

Afrezza is not recommended for patients who currently smoke or recently quit. Smoking can affect how insulin is absorbed through the lungs and may increase the risk of lung-related side effects.

Pregnant and Breastfeeding Women

Afrezza has not been adequately studied in pregnant or breastfeeding women. If you're pregnant, planning to become pregnant, or nursing, talk to your doctor about whether injectable insulin might be a safer option.

Children

Afrezza is not approved for use in children. Safety and effectiveness have not been established in patients under 18.

Kidney or Liver Impairment

Patients with hepatic or renal impairment may need dose adjustments. These conditions can affect how your body processes insulin, potentially increasing the risk of hypoglycemia.

How to Manage Common Side Effects

Here are practical tips for dealing with the most common issues:

• For cough: Take a sip of water before and after inhalation. The cough usually improves after the first few weeks. If it doesn't, tell your doctor — they may want to assess your lung function.
• For sore throat: Gargle with warm salt water and stay hydrated. Avoid inhaling Afrezza in very cold, dry air if possible.
• For hypoglycemia: Always carry fast-acting glucose (juice, glucose tablets, or regular soda). Check your blood sugar regularly, especially when adjusting doses. Learn the early symptoms — shakiness, sweating, rapid heartbeat — and treat immediately.
• For declining lung function: Keep all spirometry appointments. Your doctor will monitor your FEV1 and may adjust or discontinue treatment if lung function drops significantly.

Also be aware of drug interactions that can increase your risk of side effects, such as beta-blockers that may mask the symptoms of low blood sugar.

When to Call Your Doctor

Contact your doctor right away if you experience:

• Wheezing, chest tightness, or difficulty breathing after inhalation
• A persistent cough that worsens over time
• Signs of severe hypoglycemia (confusion, seizures, loss of consciousness)
• Symptoms of DKA: nausea, vomiting, abdominal pain, fruity-smelling breath, rapid breathing
• Any signs of an allergic reaction: rash, hives, swelling, or difficulty swallowing

If you're having trouble breathing or experience severe symptoms, call 911 or go to the nearest emergency room immediately.

Final Thoughts

Afrezza's side-effect profile is different from injectable insulins because of its unique lung-based delivery. Most patients tolerate it well — the cough and sore throat typically fade after the first few weeks, and the convenience of an inhaler over injections is a meaningful quality-of-life improvement for many people.

But the lung-related risks are real. Spirometry monitoring, honest conversations with your doctor about your respiratory health, and awareness of the serious warning signs are all essential parts of using Afrezza safely.

For more about this medication, check out What Is Afrezza? Uses, Dosage, and What You Need to Know. And if you're ready to fill your prescription, Medfinder can help you find a pharmacy with Afrezza in stock.