She walked in and found some of the tablets on the floor.
"I asked him how many he had taken and he said lots," she said.
"My first reaction was panic at the potential risk."
She called the poison centre to find out what she should do.
"The poison centre was so helpful, the person I talked to was calm and reassuring," Tyacke said.
She took James to the emergency department where they took blood tests to check the toxicity of what he had taken.
As it turns out, James had not taken enough to poison himself, but it could have been a lot worse.
Tyacke is urging parents to store their medication properly and take any unneeded medication into their local pharmacy or medical centre.
"The main thing is to really make sure that medication isn't lying around."
She said a lot of women carried Panadol in their handbags and did not put it away when they got home, so it was about being vigilant and making sure you put medication away.
She encouraged parents to talk to their kids about not taking medication they found.
"I was annoyed at myself because I'm always very careful with medication.
"I felt like such a bad mother," Tyacke said.
Compass Health is running a campaign encouraging people to check their cupboards for unwanted and out-of-date medication.
Masterton pharmacist Viv Barham said unused medication could be a risk to both adults and children.
"Spring is traditionally a time when people clear out cupboards and declutter.
"This year, we're encouraging people to check their homes and businesses for out-of-date and unused medication and return it to their local pharmacy or medical practice for safe disposal," she said.
During September people can drop off medication including pills, tablets, supplements and liquid medicine.
Val Fleet of South End pharmacy said any medication taken over and above the recommended dosage was dangerous and all medication should be kept out of reach of children, preferably in a locked cabinet.
