Round white tablet imprinted G on one side and 2622 on the other side is 5 mg terbutaline sulfate - generic Brethine. It's a bronchodilator used to treat asthma and other breathing problems.
More info:
http://brethine.drugs.com
I'm not a pharmacist or a medical doctor. This message is not medical advice nor is it an offer to provide medical advice. All drug identifications should be validated by a licensed MD or pharmacist.