Billy Hill replied: "Risperdal (risperidone) is a major tranquilizer (like thorazine and haldol) and antipsychotic drug. It can have very serious side effects, like tardive dyskinesia. This is a condition where your muscles can become permanently paralyzed (especially those in the facial region). It can cause uncontrollable tremors and salivation (drooling). It can also cause serious liver problems, and your doctor should give you periodic liver enzyme tests to make sure you're not damaging your liver. Other side effects include Stephens-Johnsons Syndrome, which starts as a rash but can eventually kill you. It can also cause fatigue and weight gain. I can't believe a doctor would give you this drug for anxiety, as it is not a first-line therapy in almost any disease these days! It is usually used in schizophrenics to stop delusions and hallucinations. There are much safer and more effective drugs out there. Fluoxetine (Prozac) sertraline (Zoloft), or escitalopram (Celexa) would be much better at treating OCD and have a much safer side-effect profile, in my opinion. They're also a little bit older and much less expensive than some of the newer SSRI's and SSNRI's. As for anxiety, those three drugs I just listed would help, but you could also try buspirone (Buspar), which is a much safer drug for anxiety with a very low abuse liability. Other drugs to treat anxiety are the benzodiazepines like clonazepam (Klonopin), alprazolam (Xanax), diazepam (Valium), or clorazepate (Tranxene). These four are all schedule IV drugs, which means they do have some potential for abuse and addiction. So, in closing, Risperdal should work very quickly in calming your thoughts, but you should talk to your pharmacist and doctor to see if there is something safer you can take."

9Suns replied: "MONITOR: Centrally-acting anticholinergic agents may antagonize the therapeutic effects of neuroleptic agents. Although these drugs have been used together clinically, the possibility of increased risk of adverse effects such as central nervous system depression and tardive dyskinesia should also be considered. In addition, excessive anticholinergic effects may occur in combination use, which can result in paralytic ileus, hyperthermia, heat stroke, and the anticholinergic intoxication syndrome. Peripheral symptoms of anticholinergic intoxication commonly include mydriasis, blurred vision, flushed face, fever, dry skin and mucous membranes, tachycardia, urinary retention, and constipation. Central symptoms may include memory loss, disorientation, incoherence, hallucinations, psychosis, delirium, hyperactivity, twitching or jerking movements, stereotypy, and seizures. In hot weather, the risk of hyperthermia and heat stroke should be considered, as neuroleptic agents can interfere with temperature regulation in the hypothalamus while anticholinergic agents tend to inhibit peripheral sweating mechanisms. MANAGEMENT: Caution is advised if anticholinergic agents are used with neuroleptic agents, particularly in the elderly and those with underlying organic brain disease, who tend to be more sensitive to the central anticholinergic effects of these drugs and in whom toxicity symptoms may be easily overlooked. Prophylactic administration of anticholinergic agents is sometimes given clinically during neuroleptic therapy for drug-induced parkinsonism or extrapyramidal symptoms but may not always be appropriate. Patients prescribed this combination should be advised to notify their physician promptly if they experience potential symptoms of anticholinergic intoxication such as abdominal pain, fever, heat intolerance, blurred vision, confusion, and hallucinations. Ambulatory patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them. A dosage reduction in one or both drugs may be necessary if excessive adverse effects develop. During hot weather, patients should avoid prolonged sun exposure and intense physical exertion and maintain adequate fluid intake. You asked almost the same question a while back, but you said 24 hours, which I would say would be OK, but now you say 18 hours, so I would NOT take the benadryl 18 hours after the risperdal. IF you are still unsure about your question, I would call up your MD and ask him to clarify."

Jeht replied: "Depends on dosage and length of time taking it. But I would trust your Doc and if you start feeling or acting funny you can always go back on.."