Pyridostigmine dosage and timing in neonates

[Guest bandino]

Dear Colleagues,

I am an adult neurologist and actually consult one of my myasthenic patients and her newborn with the department of gynecology

and our perinatal intensive care unit. The mother is free of symptoms, she is on Mestion five times /day.

The newborn has a neontal (transient) myasthenia. She is 3,5 kg, 52 cm. Fortunately she does not have severe atonic generalised weakness but has bulbar symptoms.

No problem with the swallowing at rest, but crying and sucking is week and she has relatively early fatigue when she is on breast.

She has a good reaction for pyridostigmine but the main problem is the drug supply.

When we give the drug before the breast feeding the baby becomes alert. Whe have to wait for the impact of the drug at leat 20-30 minutes, but during this period

she cries a lot therefore she becomes tired for sucking when she can start it, and within 10 minutes we hear a stridor and the sounds of the irregular deglutition from the baby pharynx.Fortunately there is no signs of aspiration.

I would like to know the following:

1. - is there any known trick(s) about optimal timing of pyridostigmine/neostigmine supply when the baby does not have such a severe symptom(s) that it makes necessary the nasogastric tube?

2. - what is the optimal dosage of pyridostigmine for a newborn? I found many data about neostigmine but I could not find detailed data about pyridostigmine dosage (mg/kg/dosage or mg/kg/day) in such a young age .

Thank you for your help

[Stefan Johansson]

I guess you have found this link to the Auckland drug database:

http://www.adhb.govt.nz/newborn/DrugProtocols/NeostigminePharmacology.htm

According to an old protocol I have kept, the recommended oral dose of pyridostigmine should be about 20 times (0.2 mg/kg) the intravenous dose of neostigmine (0.01 mg/kg).

Regarding dosing interval: I hope someone else with hands-on experience shares the experience here. I guess x2-3/24hours would be a good start.

If the baby is to weak for full breast feeding, supplemental feeding with a nasogastric tube would be a good option, while awaiting the spontaneous resolution of the neonatal myastenia.

[Guest bandino]

Dear Stefan,

Thank you very much for your valuable and quick reply.

Best regards

Andras