Applies to diphenhydramine: compounding powder, injectable solution, oral capsule, oral disintegrating strip, oral liquid, oral tablet, oral tablet chewable, oral tablet disintegrating The most commonly reported side effects included somnolence, dizziness, and incoordination. Common (1% to 10%): Sedation/somnolence/sleepiness, drowsiness, unsteadiness, dizziness, headache, attention disturbance Rare (0.01% to 0.1%): Extrapyramidal effects, tremor, convulsions Frequency not reported: Paresthesia, dyskinesia/muscle dyskinesia, vertigo, neuritis, incoordination, psychomotor impairment, activation of epileptogenic foci Rare (0.01% to 0.1%): Confusion, depression, sleep disturbances Frequency not reported: Paradoxical excitation/excitation, agitation, increased energy, restlessness, nervousness, euphoria, anxiety, hallucinations, insomnia, irritability1. Weight based dosing plaquenil Does hydroxychloroquine cause diarrhea Plaquenil and suicidal thoughts ER Dr. stated it was hives. I was given a shot of steroids, benadryl and I was to take 40mg of Prednisone for the next 4 days without a tamper down. The rash/hives got worse over the last few days. The Monday after Thanksgiving I went to my GP and she sent me to my Dermatologist immediately. I told him i felt like it was from the Plaquenil he. Hi, I started taking Plaquenil on June 24th and for the last four or 5 days have had horrible itching. No rash just all over itching. My Rhuemy told me to stop taking it until all itching symptoms were gone, then wait another week and start up again with 1 pill 200mg a day instead of 2. Because Plaquenil is the kind of drug that builds up in the blood stream and tissues I suspect, it has a very long half life. Simple drugs like abx can take as much as a month to completely clear from the body. So the Plaquenil could hang around for a while. Carry the Benadryl with you. I use the children's liquid because it goes to work faster. Benadryl (diphenhydramine)." Parke-Davis, Morris Plains, NJ. Benadryl Childrens Allergy Fastmelt (diphenhydr AMINE)." Pfizer U. Benadryl and plaquenil Plaquenil and Benadryl drug interaction High blood pressure., Itching From Plaquenil DailyStrength Hydroxychloroquine sulfate adverse reactionsPlaquenil maculopathy screeningPlaquenil cause menstrual cycleChloroquine lysosomal degradation Doctors give trusted answers on uses, effects, side-effects, and cautions Dr. Chiu on can benadryl improve lupus symptoms Antihistamines block the receptor sites for histamine released from mast cells or basophils in allergic reactions. As such they suppress symptoms to a variable amount. The only present treatment that can actually alter the allergic condition diathesis is immunotherapy. Can benadryl improve lupus symptoms - Doctor answers. Plaquenil - how long for side effects to subside?. Medications That Cause Nightmares and Disturbing Dreams.. Immune modulators Humira, Enbrel, Plaquenil Antiarrhythmics propanolol, metaprolol, Cardizem, Norvasc Antihistamines Allegra, Zyrtec, Benadryl Histamine H2 blockers Tagamet, Pepcid, Zantac Some studies suggest considering the herb HOPS and quercetin about 250 to 500 mg taken three times daily in order to reduce histamine levels. Does Plaquenil Interact with other Medications? Severe Interactions. These medications are not usually taken together. Consult your healthcare professional e.g. doctor or pharmacist for more in. Few patients consider visual symptoms as being related to their medicine. However, when you realize that your eyes are really just an extension of your brain, an organ which is extremely sensitive to many drugs, it is not surprising that vision can be impaired by a host of medications.