R.C.
Please see the medication dosage for ibuprofen: http://www.askdrsears.com/topics/childhood-illnesses/medi.... You should dose him based on weight.
Also, please skip the Hyland teething tablets as they contain an unknown amount of belladona, a very potent opiate which acts as a sedative and is addictive with frequent use. I encourage you to research them if you are tempted to try them.
A cool wet wash cloth is a great addition to the cold teether. Best wishes for peaceful nights. Nurse Midwife Mom