Hi Clover
Sever morning sickness can be very serious for both you and your baby. However if it has not been too sever then you may need to just replace fluids and water will do this providing that you can keep it down. If it is sever then you may be losing salts and minerals along with fluids and these need to be replaced. Hydrolyte can help to do this.
Zofran is commonly used to reduce the vomiting caused by chemotherapy. It is also getting more popular for morning sickness. I have heard of maxalon causing panic attacks but I have not heard of zofran doing this.