Does penicillin through an IV hurt? Understanding Intravenous Antibiotics

October 11, 2025 •

4 min read

While the initial insertion of an intravenous (IV) catheter is a momentary pinch, many patients report experiencing discomfort or a burning sensation during the infusion of certain medications. The answer to "Does penicillin through an IV hurt?" is often nuanced, as mild irritation can be common, but persistent pain is a signal to notify a healthcare provider.

Quick Summary

Pain during IV penicillin is often due to vein irritation or fluid leaking into surrounding tissue. Though mild discomfort can be expected, persistent burning or swelling requires medical attention to prevent complications.

Key Points

Initial vs. Infusion Pain: The needle insertion is a brief pinch, but the infusion of penicillin can sometimes cause discomfort or a burning sensation.
Vein Irritation is a Key Factor: The medication can irritate the vein lining (phlebitis), leading to a burning or aching feeling during infusion.
Watch for Infiltration: Persistent pain, swelling, coolness, or redness at the IV site are common signs that the medication is leaking into the surrounding tissue.
Communicate Immediately: If you experience significant or worsening pain, you must alert a nurse or healthcare provider so they can assess the IV site.
Techniques Help Minimize Discomfort: Healthcare providers can use warm compresses, proper vein selection, and controlled infusion rates to reduce pain and irritation.
IV and IM Pain Differ: Pain from an IV is typically localized to the vein and infusion, whereas an intramuscular (IM) injection, like penicillin G benzathine, causes deep muscle soreness.
Severe Pain is Not Normal: While some discomfort is possible, severe or worsening pain should never be ignored as it can indicate a more serious complication like a nerve issue or extravasation.

The Initial Pinch vs. Ongoing Pain

When receiving an intravenous (IV) medication like penicillin, patients typically feel a brief, sharp pinch or sting as the needle is inserted into the vein. This is the process of placing the small, flexible plastic catheter through which the medication will be delivered. Once the catheter is properly in place and the needle is removed, the site should not cause significant, ongoing pain. However, many factors can contribute to pain and irritation during the actual infusion, making the experience uncomfortable for some individuals.

Why Intravenous Penicillin Causes Discomfort

Several physiological and procedural factors can lead to pain or a burning sensation during an IV penicillin infusion:

Chemical Irritation (Phlebitis): The antibiotic solution itself can irritate the delicate inner lining of the vein, a condition known as phlebitis. Penicillin G, for example, is specifically noted for causing pain and irritation at the infusion site due to its formulation. This irritation manifests as a burning feeling that travels up the vein.
Infiltration or Extravasation: This is one of the most common causes of significant IV pain. It occurs when the IV catheter shifts, and the medication begins to leak out of the vein into the surrounding soft tissue. This causes swelling, a sensation of coolness, and can lead to pain or a stinging, burning feeling. If left unaddressed, it can cause severe tissue damage, especially if the medication is particularly irritating.
Improper Placement or Catheter Movement: If the catheter is not inserted correctly or moves within the vein, it can cause mechanical irritation. For instance, a larger catheter in a smaller vein can increase the risk of irritation and inflammation. Excessive movement of the limb with the IV can also cause the catheter tip to rub against the vein wall, leading to inflammation and discomfort.
Rapid Infusion Rate: Infusing the medication too quickly can overwhelm the vein, leading to a concentrated dose of the irritating substance flowing through a small area. This increases the likelihood of a burning sensation.
Patient-Specific Factors: An individual's vein condition and general health can play a role. Those with fragile veins or who are dehydrated may be more susceptible to irritation.

How Healthcare Providers Minimize IV Pain

Skilled healthcare professionals use several techniques to make IV therapy as comfortable as possible:

Proper Vein Selection: Nurses are trained to find the most suitable vein for infusion, often using one that is straight, firm, and easily accessible. They avoid overly small or fragile veins when possible.
Warm Compresses: Applying warmth to the injection site before or during infusion can dilate the veins, making them easier to access and potentially reducing pain.
Adequate Hydration: For elective procedures, healthcare providers may encourage patients to drink plenty of fluids beforehand. This helps plump up the veins, making them easier to access.
Distraction Techniques: A nurse might engage a patient in conversation or offer other distractions to help manage anxiety and shift focus away from the insertion.
Topical or Local Anesthesia: In some cases, a numbing spray or cream can be used on the skin before insertion to minimize the pain from the initial needle stick.
Controlled Infusion Rate: The rate of infusion is carefully controlled by an IV pump. For medications that can cause irritation, the infusion can be slowed to a comfortable rate.

Comparison Table: Causes of Pain During Intravenous vs. Intramuscular Penicillin


Feature	Intravenous (IV) Penicillin	Intramuscular (IM) Penicillin (e.g., Penicillin G Benzathine)
Mechanism of Pain	Direct chemical irritation of the vein lining, infiltration into surrounding tissue, or mechanical irritation from the catheter.	Injection of a large, viscous volume of medication into the muscle, causing pressure, tissue distension, and local anesthetic-like effect.
Common Sensation	Burning, stinging, throbbing, or aching at the injection site or along the vein.	Deep muscle soreness, stiffness, or intense pressure at the injection site.
Onset of Pain	Often occurs during the infusion, can persist for a short time after.	Immediate pain and discomfort upon injection, which may persist for hours or days.
Management	Slowing the infusion rate, applying warm compresses, repositioning the catheter if necessary, or switching the IV site.	Warming the medication before injection, diluting with a local anesthetic like mepivacaine, or using proper injection techniques.

What to Do If You Experience Pain

If you are receiving IV penicillin and experience pain, it is crucial to communicate with your healthcare provider immediately. Here is what you should do:

Describe the Sensation: Tell the nurse what kind of pain you feel—burning, aching, or stinging—and where it is located. This helps them diagnose the cause.
Watch for Warning Signs: Monitor for symptoms beyond mild discomfort, such as swelling, redness, coolness, or hardness at the site, which could indicate infiltration.
Report Any Numbness or Tingling: These can indicate nerve irritation or injury, which needs immediate attention.
Remain Calm: While discomfort can be distressing, staying calm helps the healthcare provider assess the situation more accurately. They will likely pause the infusion and assess the site.

Conclusion

So, does penicillin through an IV hurt? The simple answer is that it can, but it's not supposed to be a severely painful experience beyond the initial needle stick. While mild and temporary discomfort may be normal, a persistent burning sensation, pain, or any sign of swelling is a red flag for a complication like vein irritation or infiltration. The key to a safe and comfortable infusion is to communicate openly with your healthcare provider about any unusual sensations. By doing so, you can ensure any issues are addressed promptly, and your treatment can proceed effectively and with minimal discomfort.

For more information on general IV safety, you can visit the ivWatch website.

Frequently Asked Questions

Some patients experience a mild, temporary burning or stinging sensation during a penicillin infusion, which can be a normal reaction to the medication itself. However, persistent, worsening, or severe burning is not normal and may indicate a problem like vein irritation or infiltration.

IV infiltration is when the medication leaks from the vein into the surrounding soft tissue. This causes pain, swelling, coolness, and possible stinging or burning because the fluid is not being delivered properly into the bloodstream.

You should alert your healthcare provider immediately if you feel sharp or burning pain, swelling, coolness, redness, or numbness at the IV site during or after the infusion. Mild, brief discomfort during insertion is common, but ongoing pain is a reason for concern.

A nurse can minimize pain by applying a warm compress to the area to dilate the vein, ensuring proper catheter placement, slowing down the infusion rate for irritating medications, and possibly using a numbing agent for insertion.

Yes, the pain mechanisms differ. IV pain is often related to chemical irritation inside the vein or leakage, while intramuscular (IM) penicillin, like Penicillin G benzathine, causes deep muscle pain and soreness due to the large volume of medication injected directly into the muscle.

Yes, dehydration can make IV therapy more uncomfortable. Being well-hydrated makes veins plumper and easier to access, which can lead to a smoother insertion and potentially less irritation during the infusion.

Serious complications require immediate medical attention. Watch for severe swelling, significant pain that does not resolve, skin that turns purple or black, numbness or tingling in the limb, or persistent fever after the IV is removed.