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Pediatric & Adolescent Medicine

Fever: What to do?

Dosage of Fever and Pain Medicine

Fever is characterized by elevation of body temperature over 100.4 (F) or 38.0 (C) when taken rectally or over 100.0 (F) or 37.7 (C) when taken under the arm, in the  ear or on the forehead. You can find Fahrenheit to Celsius conversion table at the bottom of this page.

If your infant  is younger than 12 months, temperature should be always taken rectally.

If your infant is younger than  8 weeks and has elevated temperature, make sure she(he) is not overdressed, repeat the measurement within 1/2 hour and if it is still elevated call your doctor or go to Emergency room.

Important:

  • Children less than two months of age should not be given acetaminophen without calling the physician first.
  • Ibuprofen SHOULD NOT be given to children under six months of age.

Calculations:

  • Milliliter is abbreviated as ml or cc. 5ml equals one teaspoon (tsp). 
  • Don't use household teaspoons, which can vary in size. 
  • ‚ÄčAspirin should not be used in children to treat fever or pain.
There are two fever reducers available -acetaminophen (Tylenol)-indicated for children of any age and ibuprofen (motrin, advil)-indicated only after 6 months of age.

IBUPROFEN

(Minimum of 6 hours between doses)
Weight (lbs)
(over 6 mths)
Oral Drops
50mg/1.25ml
(1 dropper)
Suspension
100mg/5ml
(1 tsp)
Chewable Tablets
50mg
Chewable Tablets
100 mg
Caplets
100mg
12-17 1.25 ml 2.5 ml      
18-22 1.87 ml 3.75 ml 1 1/2 tabs    
23-34 2.5 ml 5 ml 2 tabs 1 tab  
35-44   7.5 ml 3 tabs 1 1/2 tabs  
45-55   10 ml 4 tabs 2 tabs 2 caps
56-66   12.5 ml 5 tabs 2 1/2 tabs  
67-88   15 ml 6 tabs 3 tabs 3 caps
89 and over   20 ml   4 tabs 4 caps

Ibuprofen: 10 mg/kg (4.5mg/lb) of body weight per one dose. 

Example: You have 9 month old baby who weighs 18 lb (8 kg).
  • 18 lbx4.5mg=80 mg
  • 8kgx10mg=80 mg
  • Infant's ibuprofen comes in droppers where 100 mg of medicine contains in 2.5 ml.
  • So if you need 80 mg you should take 2 ml of infant Ibuprofen drops.
Please pay attention that Infant's Ibuprofen is twice as concentrated as Children's Ibuprofen. 
 

ACETAMINOPHEN

(Minimum of 4 hours between doses)
Weight (lbs) Infant/Children's 
Suspension 160mg/5ml (1tsp)
Children's Chewable
Tablets 80mg
Junior Strength
Chewables or Caplets 160mg
6-11 1.25 ml    
12-17 2.5 ml    
18-23 3.75 ml    
24-35 5 ml 2 tabs  
36-47 7.5 ml 3 tabs  
48-59 10 ml 4 tabs 2 tabs
60-71 12.5 ml 5 tabs 2 1/2 tabs
72-95 15 ml 6 tabs 3 tabs
96 and over     4 tabs

Acetaminophen: 15mg/kg (7mg/lb) per 1 dose.

Example: You have 9 month old baby who weighs 18 lb (8 kg).

  • 18 lbx7mg=120 mg
  • 8 kgx15mg=120 mg
  • 5 ml of infant's Tylenol contains 160 mg.
  • In order to get 120 mg you take 4 ml of infant Tylenol drops.
 

If this is too complicated or if you don't know exactly your baby's weight, please use the table above.

 

Recommended dosages on labels are often limited only to children older than 2 years. Using the instruction below you can calculate a dosage for any age, using weight of a child. It is also helpful when your older child is not of average size, lighter or heavier than average. It is highly accurate up to age 12 when we start giving children regular adult dose.