Thanks for putting your query up at HealthCareMagic. I understand the cause of concern. Let me mention that the tolerated but common side effect of anti-allergics like Benadryl is sleepiness. Amoxycillin is an antibiotic and while killing the bad bugs it also eliminates the good bacteria that reside in our bowels. As a result sometimes mild diarrhoea or signs of vitamin B deficiency may occur. It can be overcome by giving curd/yogurt which contain lactobacilli. Prebiotics and probiotics (available in brand names like Vizylac, enterogermina) can also be give. Tylenol is a very safe drug. Let me tell you that these are very frequently used and safe drugs and you need not worry about serious side effects when giving these drugs. I hope that helps. Feel free to revert back with further queries if any.