I've Been Taking Clopidogrel 75 Mg For 7 Days Then

I've been taking clopidogrel 75 mg for 7 days then I was prescribed hydrocodone for sciatica and took 1 1/2 pills twice a day as I needed for pain. On the 5 th day of taking both drugs, my palms and bottoms of my feet started itching terrible. Which drug is most likely causing the itching? Took Benidryl a couple times to stop itching.