Sodium Chloride Side Effects: What You Need to Know

Sodium Chloride — commonly known as saline — is one of the most widely used medications in healthcare. While it's generally very safe, it can cause side effects, particularly when given intravenously in large amounts or when used in concentrated (hypertonic) formulations.

This guide covers the side effects you're most likely to encounter, the serious warning signs that require immediate medical attention, and practical tips for managing any discomfort.

What Is Sodium Chloride?

Sodium Chloride is a sterile salt-water solution used to treat dehydration, replace fluids, deliver medications, irrigate wounds, and manage various medical conditions. It comes in many formulations including IV solutions (0.9%, 3%, 5%), nasal sprays, nebulizer solutions, and ophthalmic drops. It is not a controlled substance and is manufactured by companies including Baxter International, B. Braun, ICU Medical, and Fresenius Kabi.

Common Side Effects

Most people tolerate Sodium Chloride well, but here are the side effects reported most often:

IV Sodium Chloride

• Injection site reactions — Pain, redness, or swelling at the IV insertion site. This is the most common complaint and is usually mild.
• Fluid overload and peripheral edema — Swelling in the hands, feet, or ankles from receiving too much fluid. You may notice your rings feel tight or your socks leave marks.
• Hypernatremia — Elevated sodium levels in the blood, which can cause thirst, dry mouth, and restlessness. This is more common with hypertonic solutions.
• Hyperchloremic metabolic acidosis — When large volumes of 0.9% Sodium Chloride are given, the high chloride content can shift the body's acid-base balance. This is typically only a concern in hospital settings with aggressive fluid resuscitation.

Nasal Formulations

• Nasal stinging or irritation — A brief burning sensation when spraying saline into the nose is common and usually fades within seconds
• Sneezing — Some people sneeze briefly after using nasal sprays or rinses
• Runny nose — Temporary increase in nasal drainage after irrigation

Ophthalmic Formulations (Muro 128)

• Temporary blurred vision — Especially with the ointment formulation, vision may blur for several minutes after application
• Mild stinging or burning — Brief discomfort upon instillation that resolves quickly

Nebulized Sodium Chloride

• Coughing — Especially with hypertonic (3% or 7%) solutions, coughing during or after treatment is common
• Throat irritation — Some dryness or scratchiness in the throat
• Bronchospasm — Tightening of the airways, particularly with hypertonic formulations. Your doctor may recommend using a bronchodilator before nebulizing hypertonic saline.

Serious Side Effects

While rare with proper medical supervision, these serious side effects require immediate medical attention:

Pulmonary Edema

Fluid in the lungs from receiving too much IV saline. Symptoms include: sudden shortness of breath, difficulty breathing while lying down, wheezing, coughing up frothy or pink-tinged sputum, and rapid heart rate. Call 911 or go to the ER immediately.

Congestive Heart Failure Exacerbation

Excess fluid can overwhelm a weakened heart. Symptoms include worsening shortness of breath, rapid weight gain (more than 2-3 pounds overnight), severe swelling in legs and feet, and inability to lie flat. If you have a history of heart failure, your medical team should be monitoring you closely during IV saline administration.

Severe Hypernatremia

Dangerously high sodium levels can cause confusion, agitation, seizures, muscle twitching, and in extreme cases, coma. This is most likely with hypertonic (3% or 5%) solutions, which is why they are only administered in ICU settings with frequent lab monitoring.

Cerebral Edema

If hypertonic saline is administered too rapidly, it can cause dangerous brain swelling. This is extremely rare with proper medical protocols but is the reason hypertonic solutions require ICU-level monitoring.

Febrile Response or Infection

Contaminated IV solutions can cause fever, chills, and potentially life-threatening bloodstream infections. This is rare with modern manufacturing standards but is why IV saline should only be administered with sterile technique.

Extravasation and Tissue Necrosis

If hypertonic Sodium Chloride leaks out of the vein and into surrounding tissue, it can cause severe tissue damage. Symptoms include burning pain, swelling, and skin changes at or near the IV site. Alert your nurse immediately if you feel increasing pain at your IV site.

Who Is Most at Risk for Side Effects?

Certain groups need extra caution with Sodium Chloride:

Heart Failure Patients

If you have congestive heart failure, your heart may not be able to handle extra fluid. Your doctor will carefully calculate fluid volumes and may choose a slower infusion rate or smaller volumes.

Kidney Disease Patients

Impaired kidneys can't efficiently remove excess sodium and fluid. Electrolyte monitoring is essential, and your nephrologist may prefer alternatives like Lactated Ringer's or Plasma-Lyte.

Elderly Patients

Older adults are more susceptible to fluid overload and electrolyte imbalances because kidney function naturally declines with age. Lower volumes and slower infusion rates are typically used.

Patients with Liver Cirrhosis or Edema

Conditions that cause fluid retention make IV Sodium Chloride riskier. Your doctor will weigh the benefits carefully.

Patients with Hypertension

Extra sodium can raise blood pressure. If you already have high blood pressure, your medical team will monitor you more closely during IV saline therapy.

Pregnant Women

Sodium Chloride is generally safe during pregnancy when clinically indicated, but excessive fluid administration can cause complications. Your OB/GYN or maternal-fetal medicine specialist will manage dosing carefully.

Pediatric Patients

Children require weight-based dosing calculations. Fluid overload can occur more quickly in small bodies, so pediatric IV rates are carefully controlled.

How to Manage Sodium Chloride Side Effects

For IV Side Effects

• Injection site pain: Ask your nurse about repositioning the IV or applying a warm compress
• Swelling: Elevate your feet if you notice ankle swelling. Report it to your care team — they may slow the infusion rate
• Thirst or dry mouth: These may indicate rising sodium levels. Don't ignore them — let your medical team know

For Nasal Side Effects

• Stinging: Ensure the solution is at room temperature (cold saline stings more). Breathe gently through your mouth while spraying.
• Irritation: If nasal sprays consistently irritate you, try a gentler delivery method like a NeilMed squeeze bottle or Neti pot

For Ophthalmic Side Effects

• Blurred vision: Don't drive immediately after applying Muro 128 ointment. Drops cause less blurring than ointment.
• Stinging: Keep drops refrigerated — cool drops tend to sting less

For Nebulizer Side Effects

• Coughing: Your doctor may recommend inhaling a bronchodilator (like Albuterol) 15 minutes before nebulizing hypertonic saline
• Throat irritation: Drink water after your nebulizer treatment and rinse your mouth

When to Call Your Doctor

Contact your healthcare provider if you experience:

• Swelling that doesn't go down or keeps getting worse
• Rapid weight gain (more than 2 pounds in 24 hours)
• Persistent headache or confusion
• Difficulty breathing or shortness of breath
• Chest pain or rapid heartbeat
• Fever or chills during or after IV therapy
• Severe pain, swelling, or skin changes at an IV site
• Seizures or muscle twitching

Call 911 immediately if you experience sudden severe shortness of breath, chest pain, seizures, or loss of consciousness.

Final Thoughts

Sodium Chloride is one of the safest and most essential medications in medicine. Most side effects are mild and manageable, especially with outpatient formulations like nasal sprays and eye drops. The serious risks primarily apply to IV administration, particularly in patients with heart, kidney, or liver conditions.

The best way to avoid side effects is to use Sodium Chloride exactly as prescribed and communicate openly with your healthcare team about your medical history. For more information, read our guide on how Sodium Chloride works or learn about drug interactions to watch for.

Need to fill your Sodium Chloride prescription? Use Medfinder to check pharmacy availability near you.