sharp head pain while coughing is this herx

I really don't know much about using this medication, but even with all the herxing I've gone through, I've not experienced head pain while coughing as part of a herx. It sounds more like a symptom.

Hopefully, those that have used this medication will be along shortly and can give you their experiences.

I have no idea about an anti-parasitic drug and its side effects. I definitely think you should call your doctor and relay this symptom to him/her. But since this is a weekend, maybe just call the pharmacist and ask them if it is a side effect.