Although 1 teaspoon is equal to 5 ml, you should never use a kitchen teaspoon to give your child his or her medication. Use proper measuring syringe or medicine cup to measure the quantity of medication. Always quantify the fever before giving medication. 

Tylenol – Acetaminophen: 
Keep in mind that you shouldn’t give infants under 12 weeks Tylenol without consulting your pediatrician (pain or fever at this age should be investigated quickly).
Indication: Fever, with temperatures above 100.4F How frequently: Repeat every 6-8 hours as needed, should not give more than 5 doses a day.Caution: Too much Acetaminophen can cause Liver toxicity. 
When using Children’s Tylenol Suspension Liquid, which has concentration of 160 mg per 5 ml:

• 6 to 11 pounds = 1.25 ml or 40 mg
• 12 to 17 pounds = 2.5 ml or 80 mg
• 18 to 23 pounds = 3.75 ml or 120mg
• 24 to 35 pounds = 5 ml or 160 mg
• 36 to 47 pounds = 7.5 ml or 240 mg
• 48 to 59 pounds = 10 ml or 320 mg
• 60 to 71 pounds = 12.5 ml or 400 mg
• 72 to 95 pounds = 15 ml or 480 mg
• Over 96 pounds = 500 mg – 15.5 ml 

In addition to Tylenol Suspension Liquid for infants and children, other forms of Tylenol include:

• Children’s Tylenol Meltaways Chewable Tablets – 80 mg per tablet
• JR Tylenol Meltaways Chewable Tablets – 160 mg per tablet
• Adult 325 mg tablets (if your child can swallow pills)
• Adult 500 mg tablets
• FeverAll is acetaminophen rectal suppository available in 3 strengths – infants (80mg) Children’s (120mg) Juniors (325mg). This is an effective dosing alternative for children who won’t or can’t take medication orally due to nausea, vomiting or irritability.

Ibuprofen – Motrin, Advil.
Indication: Pain and/or fever, it’s an anti-inflammatory medicine. Don’t use for infants under 6 months of age unless told by your child’s doctor.How frequently: Repeat every 6-8 hours as needed.Caution: Ibuprofen should always be taken with some food/snacks and never on empty stomach. It can increase the acidity in the stomach and cause stomach upset. 
Available forms: Infant drops – 50 mg/1.25 ml; Children’s 100 mg/ 5 ml; Chewables 100 mg tablets; Junior strength tablets 100 mg; Adult tablets 200 mg 

• 12 to 17 lbs – 50 mg 
• 18 to 23 lbs – 80 mg
• 24 to 35 lbs – 100 mg
• 36 to 47 lbs – 150 mg
• 48 to 59 lbs – 200 mg
• 60 to 71 lbs – 250 mg
• 72 to 95 lbs – 300 mg
• Over 95 lbs – 400 mg adult dose. 

Benadryl – Diphenhydramine: 
Indication: Allergic Reactions, Hives, itching. Don’t use under 1 year of age, as it causes most babies to be sleepy. Use with caution under 4 yrs of age. 
How frequently: Repeat every 6-8 hours as needed.Caution: Yes, you can cause overdose with benadryl, try not to do more than 3 doses in a day. 
Available forms: Benadryl liquid – 12.5 mg / 5 ml Benadryl fast melts chewable – 12.5 mg per tablet.Benadryl adult tablet – 25 mgBenadryl adult capsule – 25 mg

• 25 to 37 lbs – 5 ml = 12.5 mg
• 38 to 49 lbs – 7.5 ml = 18.75 mg
• 50 to 99 lbs – 10 ml = 25 mg
• over 100 lbs – adult dose 50 mg