Remember the worse side effect in the study was from a subject that was taking the placebo - vomiting blood! Try not to create problems overthinking this. That said, the Clavulanic acid really kicks it up. It's cerainly not candy, and there are some things to consider.
Antibiotics can be rough on the liver. If you are experiencing some atypical reactions, flu like symptoms, you may need to have liver profile monitored or do the single dose, or just the Amoxicillin. If you have had any liver damage like hepatitis, this could be a concern.
Taking over the counter medications for typical reactions are fairly well known and a pharmacist would be a great source.
Some of the more natural ways to deal with antibiotic side effects:
Stomach upset is the usual complaint, followed by yeats infections. Taking pro-biotics is beneficial and this would be the place to start. There are many available and yogurt in addition as well.
Most will experience loose bowels; some natural remedies are raspberry leaf tea, lotus seeds or kudzu. Others may experience constipation, so things like high fiber foods; flaxseed, psyllium... Taking fish oil, vitamin C and A may help mucus membranes that antibiotics can effect.
To help prevent yeast overgrowth, green tea and extract as well as Castor oil, onions and garlic may provide an additional measure of protection with the yogurt and pro-biotics. Ginger root and tea may help with nausea.
Try to eat more complex carbs. Simple carbs quickly convert to glucose - this can effect the immune system as well. So, a good diet with vegetables and fruits, good protein sources like nuts, chicken, beans, halibut and salmon. Maitake and shiitake mushrooms can help boost immunity. Thymus extract, zinc and vitamin C as well. Remember, starchy and sugary foods are more difficult to digest.
The liver can be assisted with leafy dark green vegetables like collards, kale, beets, artichokes and broccoli. Milk thistle, along with mushrooms are good liver supplements. Also, sulfur based amino acids can help the liver; (DMSA) dimercaptosuccinic acid or (SAMe) s-adenosyl methionine.