By Dr. Anita Sabeti, MD | Beverly Hills Pediatrician
Every parent knows the sinking feeling of a midnight fever. Your child is burning up, uncomfortable, and unable to sleep. You reach for the medicine cabinet, but in your exhausted state, the questions start racing: Is this the right bottle? How much do I give? When did we last do this?
This guide is designed to be the only resource you will ever need regarding Acetaminophen (commonly known by the brand name Tylenol). As a pediatrician, I want to move you past the guessing game and give you the clinical data you need to dose your child safely.
Part 1: The Clinical Data
Before we get to the numbers, you need to verify you have the right medication.
- Generic Name: Acetaminophen
- Common Brand Names: Children’s Tylenol, Little Remedies Fever/Pain Reliever, PediaCare, Triaminic, Mapap, FeverAll (Suppositories).
- Drug Class: Analgesic (pain reliever) and Antipyretic (fever reducer).2
- Mechanism of Action: Acetaminophen works by elevating the body’s overall pain threshold and acting on the heat-regulating center of the brain (the hypothalamus) to lower fever.3
The “Concentration Change” Safety Note
Crucial Data Point: In the past, “Infant” drops were concentrated ($80mg / 0.8mL$) while “Children’s” liquid was diluted. This caused confusion and overdoses.
Current Standard: Today, almost all liquid acetaminophen for children is standardized to $160mg / 5mL$.
Always double-check the “Drug Facts” label on the back of your bottle to confirm this concentration.
Part 2: The Master Dosage Chart
Dosage Rule: Always dose by WEIGHT, not age. Age is just an estimate; weight is clinical precision.
Frequency: Every 4 to 6 hours.
Maximum: Do not exceed 5 doses in a 24-hour period.
| Weight (lbs) | Weight (kg) | Liquid (160mg/5mL) | Chewable Tablets (160mg) | Adult Tablets (325mg) | Rectal Suppositories (FeverAll) |
| 6–11 lbs | 2.7–5 kg | 1.25 mL | — | — | Consult Doctor |
| 12–17 lbs | 5.5–7.7 kg | 2.5 mL | — | — | 80 mg |
| 18–23 lbs | 8.2–10.5 kg | 3.75 mL | — | — | 120 mg (approx) |
| 24–35 lbs | 10.9–15.9 kg | 5 mL (1 tsp) | 1 tablet | — | 160 mg |
| 36–47 lbs | 16–21 kg | 7.5 mL | 1 ½ tablets | — | 240 mg (approx) |
| 48–59 lbs | 22–26 kg | 10 mL (2 tsp) | 2 tablets | 1 tablet | 325 mg |
| 60–71 lbs | 27–32 kg | 12.5 mL | 2 ½ tablets | 1 tablet | 325 mg |
| 72–95 lbs | 33–43 kg | 15 mL | 3 tablets | 1 ½ tablets | 325-650 mg |
| 96+ lbs | 44+ kg | 20 mL | 4 tablets | 2 tablets | 650 mg |
(Note: Suppositories often come in 80mg, 120mg, 325mg, and 650mg strengths.4 Use the closest formulation to the liquid equivalent.)
Part 3: When Liquid Isn’t an Option (Suppositories)
One of the most frequent questions I get is: “My child has a fever but is vomiting everything up. How can I give them Tylenol?”
In this scenario, oral medication is useless. You need Acetaminophen Suppositories (Brand name: FeverAll).
- What they are: Small, waxy pellets inserted rectally. They melt quickly and are absorbed directly into the bloodstream.
- Why use them: They bypass the stomach, so vomiting won’t affect the dose.
- How to use:
- Wash hands thoroughly.
- Lie your child on their side with the bottom leg straight and the upper leg bent forward (towards the stomach).
- Gently insert the suppository into the rectum using a gloved finger or pinky.
- Hold the buttocks together for 30–60 seconds to prevent the child from pushing it out.
Part 4: Safety Protocols & Toxicity
Acetaminophen is safe when used correctly, but it is metabolized by the liver.5 Overdosing can lead to liver damage.6
Signs of Overdose:
If you suspect your child has taken too much, do not wait for symptoms. Call Poison Control (1-800-222-1222) immediately. Early symptoms of liver toxicity can be subtle but include:
- Nausea and vomiting (persisting after the illness should have passed).
- Abdominal pain (specifically on the upper right side).
- Jaundice (yellowing of the skin or whites of the eyes).7
- Confusion or extreme lethargy.
The “Hidden Tylenol” Trap:
Many “Multi-Symptom” cough and cold medicines contain acetaminophen.8
- Example: If you give your child a dose of “Multi-Symptom Cough & Cold” AND a dose of Tylenol, you have just double-dosed them.
- My Advice: Stick to single-ingredient medications. If they have a fever, give Tylenol. If they have a runny nose, treat the runny nose. Do not mix them in one “cocktail” bottle.
Part 5: Frequently Asked Questions (FAQ)
Q: Can I give Tylenol on an empty stomach?
A: Yes. Unlike Ibuprofen (Motrin/Advil), which can irritate the stomach lining, Acetaminophen is generally gentle on the stomach and can be taken with or without food.9
Q: Can I mix the medicine with milk or juice?
A: Yes, but with a caveat. You must ensure the child drinks all of the mixture to get the full dose. I recommend mixing it with a very small amount (e.g., 1 ounce) of liquid so it’s easy to finish, rather than a full bottle.
Q: My child is under 12 weeks old (3 months). Can I use this chart?
A: No. If an infant under 12 weeks has a fever ($100.4^{\circ}F$ rectal or higher), this is considered a medical emergency. You should not give medication to mask the fever; you need to go to the ER or call your pediatrician immediately to determine the cause of the infection.
Q: Tylenol isn’t working. Can I switch to Motrin?
A: If your child is over 6 months old, yes. Some parents alternate between Tylenol and Motrin every 3 hours. However, this increases the risk of dosing errors. I usually recommend sticking to one medication unless the fever is very high and stubborn. (See my guide on Alternating Medications for the strict schedule).
