The dosage of famotidine being given is a little on the high side at 60mg being given every 12 hours. The highest dosage recommended for this medication is 30mg as often as twice daily.
Studies have shown that omeprazole (prilosec) may be more useful than famotidine in addressing nausea. If the famotidine has not helped, I would try a switch to omeprazole. If you choose to use this medication (which is safe to use with the phenobarbital) 30mg can be given but it only needs to be dosed once daily.
With the stress and him feeling unwell, there's no way to prevent a seizure if it's going to happen aside from minimizing his stimulus and providing the medication he's supposed to have. I would wait at least 2 hours following the omeprazole to try giving fluid (start with water and work your way up to a fluid-based food like pureed baby food in chicken, turkey and similar flavors. Avoid those that contain onion or garlic in the ingredient panel). Once he is holding both fluid and baby food down for 6 hours, try some boiled rice and chicken.
To make this, you’ll combine white or brown rice, boneless, skinless chicken breast and sufficient water for cooking in a stock pot. Boil on medium until it turns to mush and the breast is easily flaked. You can mix in the baby food if needed to entice him. Work up to feeding exclusively until at least 3 days following the resolution of symptoms. After this, work on slowly switching back to the regular food that your companion typically eats over 10 days. My recommendation is a 10% switch every day. Day 1: 10% new food, 90% old food; Day 2: 20% new food, 80% old food; Day 3: 30% new food, 70% old food, etc. This slow switch process should minimize any risk of GI upset from changing food.
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