A list of drugs that cause liver damage can be found here:
http://www.hepcnet.net/drugsandliverdamage.html
Mike H
Diphenhydramine hydrochloride (commonly sold as benedryl) is an antihistamine which makes patients drowsy, so is taken in higher doses at bedtime to make patients sleep. It is sold in 25 mg pills and as extra strength, 50 mg pills. I found a list of drug recommendations on the Janis & Friends site last year and it said that patients were allowed up to 200 mg per night while on IFN/ribivirin therapy and it's what I used for sleep throughout TX. It is sold over-the-counter as Sominex and a lot of other store brands.
There is another antihistamine sold as a sleep aid: doxylamine. I have not used it, but it must operate under the same principal: older antihistamines can make you sleepy. desrt's link to drugs.com will take you to all of the available antihistamine info. That same site also says that these antihistamine sleep aids are not for people with glaucoma or kidney disease.
For use as a sedative (to help sleep):
For diphenhydramine
For oral dosage forms (capsules, tablets, or liquid):
Adults: 50 milligrams (mg) twenty to thirty minutes before bedtime if needed.
http://www.drugs.com/cons/unisom-sleepgels-maximum-strength.html