"Rob Portman isn't just talking about the situation. He's getting things done. I trust Rob Portman 100 percent. He's going to see this thing through," Wayne Campbell says in the ad. 
Campbell's son, Tyler, died from an overdose in 2011. 
The Centers for Disease Control and Prevention reported earlier this year that there were more deaths from drug overdoses than car accidents in 2014. 
The online ad, titled "Tyler," will begin running Wednesday and is part of a larger ongoing six-figure online ad buy from the campaign. 
In a note from Campbell, which will be released by the campaign, he adds that Ohioans "are fortunate to have a partner" in Portman. 
"For over 20 years, Rob has been leading the charge on drug prevention and treatment efforts," he writes. 
Portman is facing a tough reelection bid against former Ohio Gov. Ted Strickland. Portman trails the Democrat slightly, according to polls.
Portman's campaign has focused on his effort to combat the growing drug addiction epidemic as he runs for reelection. The Senate passed the Comprehensive Addiction and Recovery Act from Portman and Sen. Sheldon WhitehouseSheldon WhitehouseFederal judges should be allowed to be Federalist Society members Warren condemns 'horrific' Trump tweet on Minneapolis protests, other senators chime in IRS proposes guidance for expanded carbon capture tax credit MORE (D-R.I.) earlier this year. 
The legislation authorizes funding for programs to combat prescription opioid abuse, in addition to increasing the availability of naloxone, a drug to treat overdose.
It also gave Portman and Majority Leader Mitch McConnellAddison (Mitch) Mitchell McConnellRosenstein steps back into GOP crosshairs Biden to deliver remarks in Philadelphia Tuesday on nationwide protests Senate Republicans urge Trump to tone down rhetoric on protests MORE (R-Ky.) an election-year win. Republicans are defending 24 Senate seats, including a handful — like Ohio — in states previously carried by President Obama.
Portman has also beeen speaking from the Senate floor on a weekly basis to urge the House to take up legislation to combat drug overdose. 

"I take House leadership at their word when they say that they want to move this legislation and move it through regular order. I understand that, but I will say this: They need to move, and they need to move quickly because of the urgency of this issue," he said from the Senate floor last week. 

Democrats, however, quickly pounced on the legislation, saying Republicans were trying to brush over mixed voting records on opioid abuse funding. 

Portman voted against a spending bill late last year that included extra funding to help combat opioid abuse, though his opposition was unrelated to the funding for the drug crisis.