Lyme Disease Children’s Treatment Dosages

DISCLAIMER: Caudwell LymeCo charity shares public domain  information, which it believes to be reliable, in good faith. It should never replace the advice of a qualified physician with a license to practise medicine. If you believe any information on this website to be incorrect, you are invited to contact the charity using the Contact page.

There are 4 different antibiotics recommended in the NICE Guideline for Lyme disease to treat children aged 12 and under for Lyme disease.

  • For children aged 9 to 12 years, the treatment is usually doxycycline or amoxycillin.
  • For children below 9 years of age, the treatment is usually amoxycillin or azithromycin.
  • Ceftriaxone is occasionally given via a drip in hospital for very severe cases of Lyme disease. 

Children who are older than 12 should be given the same treatments and doses as adults.

The calculations below will give quantities which are then rounded off to the nearest number available as tablets or on syrup measuring syringes. This means very small variations between the dosage calculated from a child’s weight, and the dosage prescribed, are to be expected.

Amoxycillin dosage

Take your child’s weight in kilogrammes.

Multiply it by 30.

This is the amount of Amoxycillin in milligrammes (mg) that your child should be given THREE TIMES per day, for 21 days.

Example

David weighs 25kg.

25 x 30 = 750

David should be given 750mg of Amoxycillin THREE TIMES per day. (This equals, altogether, 2,250mg of amoxycillin EACH day.)

Maximum weight

If your child weighs any more than 33kg, they should take the ADULT DOSE of amoxycillin which is 1,000mg three times per day, making a total of 3,000mg per day.

Special advice

The dosage of amoxycillin for Lyme disease is much higher than the dosage for some other, more common infections, and we sometimes hear of doctors who prescribe the standard dose, which may not be enough to treat Lyme disease successfully. If you think your child may have been prescribed a significantly lower dose than is recommended, we suggest you contact your GP surgery to ask if the dosage can be checked against the NICE guideline. You may alternatively ask your pharmacist to double-check for you.

Doxycycline dosage

If your child is over 9 years of age, they may be prescribed Doxycycline.

Take your child’s weight in kilogrammes.

Multiply it by 2.5

This is the amount of Doxycycline in milligrammes (mg) that your child should be given TWICE on day one of treatment then ONCE per day for the next 20 days.

In severe infections with Lyme disease, the doctor may prescribe a DOUBLE DOSE for the whole 21 days instead of just for the first day.

Example

Lilly weighs 43kg.

43 x 2.5 = 107.5 and 107.5 x 2 = 215

Lilly should be given 215mg of Doxycycline ONCE on day one and then 107.5mg of doxycycline ONCE per day for the next 20 days.

Maximum weight

If your child weighs any more than 45kg they should be given the adult dose of Doxycycline, which is 100mg taken TWICE per day for 21 days.

Special advice

Doxycycline should never be taken with foods rich in calcium. You can still drink milk but it should be at least 2 hours away from any dose of doxycycline. Remember that rice milk and nut milks often have calcium added and should also be avoided.

If the medicine makes your child feel sick, they can take half their daily dose in the morning and the other half in the evening.

Your child should not lie down for about 2 hours after taking it. It is usually recommended to take doxycycline on an empty stomach but if this makes your child feel nauseous, then they can take it with meals.

Azithromycin dosage

Azithromycin may be used if there is a reason your child cannot take either of the alternatives.

Take your child’s weight in kilogrammes.

Multiply it by 10.

This is the amount of azithromycin in milligrammes (mg) that your child should be given ONCE per day for 17 days.

Example

Emily weighs 21kg.

21 x 10 = 210.

Emily should be given 210mg of Azithromycin ONCE per day for 17 days.

Maximum weight

If your child weighs anything more than 50kg they should be given the adult dose of azithromycin which is 500mg ONCE per day for 17 days.

Special advice

Azithromycin should not be given to people with heart problems. If your child develops any symptoms while being given azithromycin which could be heart problems, contact your doctor immediately.