Brief Answer:
there are some things you can try...

Detailed Answer:
Hello,

any drug may cause allergic reactions. Other potential causes of drug-induced itching include liver injury by the drug and increased bilirubin in the blood. Bilirubin will cause yellow skin discoloration and dark brown urine (resembling to cognac). An antihistamine drug may reduce the itchiness if it's allergic in nature.

Substituting prevacid for ranitidine might be helpful because ranitidine belongs to a different drug class and also provides minor protection against allergies. Therefore if prevacid causes your symptoms, stopping it may resolve the situation.

If clopidogrel caused this itchiness then it would have to be substituted too, either with aspirin or other antiplatelet drugs. If the reaction is not pretty severe then the patient may try to stop one drug at a time only and continue taking the other. If you can stand the symptoms then stopping both and reinstituting them at different times will help to find out which one caused this problem.

Of course you should talk with your doctor first. Sometimes the doctor does not want the patient to stop the treatment, because of the risk for bleeding (regarding prevacid) or thrombosis (clopidogrel).

I hope you find my comments helpful!
You can contact me again, if you'd like any clarification or further information.

Kind Regards!

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