Published
March 9, 2018
•
Reviewed by
a UI Health Care Provider
on
Oct. 23, 2025
What is L.M.X.4®?
L.M.X.4 is 4 percent lidocaine cream. You can buy it over-the-counter. It numbs the skin so needles do not hurt as much. It can be used with:
- Immunizations (shots)
- IV starts
- Blood draws
- Port access
The cream is placed on intact skin at least 30 minutes before the procedure.
- For a baby less than 3 months, it can be left on the skin up to 60 minutes.
- For children over 3 months old, it can be left on the skin up to 120 minutes.
How do I use L.M.X.4?
The cream is placed on intact skin at least 30 minutes before the procedure.
- If your child is allergic to lidocaine or has severe liver disease
- On open skin, such as a cut, rash, or blister
- On eyes or inside the mouth, ears, or nose
To apply the cream:
- Do not clean the skin first.
- Wear gloves.
- Rub a small amount of cream ontthe site for 30 seconds.
- In a thick layer, put the rest of the dose ontthe site. Do not rub it in.
- Cover with a dressing (Tegaderm or Glad Press ’N Seal). Do not flatten the cream.
- Wash your hands.
- Write down the time the cream was put on.
Do not:
- Let your child lick or eat the cream
- Put on more than ordered
- Flatten the cream. It will leak out under the dressing.
You or your health care provider can:
- Take the dressing off
- Wipe the cream off of the skin. The cream works for 60 minutes after it has been wiped off of the skin. The skin will be cleaned before the procedure.
Do not leave the cream on longer than 60 minutes for a newborn baby or 120 minutes for a child over 3 months old.
Placing the Cream
How much cream is needed?
Your child's health care provider can tell you how much cream to apply.
| Child's weight | Amount of cream | Size of dose | Application |
|---|---|---|---|
| < 11 pounds | 1 gram | 2 pennies stack on top of each other | 1 time per day |
| 11-22 pounds | 1 gram | 2 pennies stack on top of each other | 2 times per day |
| 22-43 pounds | 2.5 grams | size of a quarter | 4 times per day |
| >43 pounds | 2.5 grams | size of a quarter | 8 times per day |
- Itching, redness, swelling, or a rash may occur. Wipe the cream off and tell your doctor if this happens.
- If your child has signs of an allergic reaction, wipe the cream off and call your doctor or 911. Signs are:
- Fever
- Wheezing
- Hives
- Feeling short of breath
- Swelling
Who do I call if I have a question?
Call your child’s doctor, pharmacy, or University of Iowa Stead Family Children’s Hospital at 1-800-777-8442.
Other instructions:
- Keep medicine out of the reach of children.
- Store at room temperature.
- Call the Poison Control Center at 1-800-222-1222 right away if tomuch medicine is used
or swallowed.
Revised 01/2022 – CWS Nursing
Approved 01/2022 – Patient Education Program