Antihistamines hypertension caused

The antidiarrheal drugs cause an additive CNS depression when administered with alcohol, antihistamines, narcotics, and sedatives or hypnotics. There are additive cholinergic effects when administered with other drugp having anticholinergic activity, such as antidepressants or antihistamines. Concurrent use of the antidiarrheals witii a monoamine oxidase inhibitor increases the risk of a hypertensive crisis. 

Dronabinol (Marinof) [C-ll] [Anriemeric, Appetite Stimulant/ Antivertigo] Uses N/V associated w/ CA chemo appetite stimulation Action Antiemetic 4- V center in the medulla Dose Adults Peds. Antiemetic 5-15 mg/m2/dose q4-6h PRN Adults. Appetite stimulant 2.5 mg PO before lunch dinner max 20 mg/d Caution [C, ] Contra Hx schizophrenia, sesame oil hypersensitivity Disp Caps SE Drowsiness, dizziness, anxiety, mood change, hallucinations, depersonalization, orthostatic 4- BP, tach Interactions T Effects W/ anticholinergics, CNS depressants, EtOH 4- effects of theophylline EMS Use caution w/ sympathomimetics, can T hypertension and tach use caution w/ anticholinergics and antihistamines, can T tach concurrent EtOH use can T CNS depression this is a principal psychoactive substance present in marijuana OD May cause extreme psychiatric effects (anxiety, mood changes and depersonalization) keep pt in a quiet environment and provide reassurance activated charcoal may be effective... 

Among the materials which may be dangerous in combination with MAO inhibitors are sedatives, tranquilizers, antihistamines, narcotics, and alcohol -- any of which can cause hypotensive crisis (severe blood pressure drop) and amphetamines (even diet pills), mescaline, asarone, nutmeg (active doses), macromerine, ephedrine oils of dill, parsely or wild fennel beer, wine, cocoa, aged cheeses, and other tyrosine-containing foods (tyrosine is converted into tyramine by bacteria in the bowel) -- any of which can cause hypotensive or hypertensive (severe blood pressure rise) crises. 

Promethazine causes sedation by reducing stimuli to the brain stem reticular system. Like other antihistamines, promethazine has significant anticholinergic effects it should be used with caution in patients with narrow-angle glaucoma, peptic ulcer, or pyloroduodenal obstruction or urinary bladder obstruction from prostatic hypertrophy or narrowing of the bladder neck. It also should be used with caution in patients with CVD or hypertension because of the risk of palpitations with acute or chronic respiratory dysfunction (especially children) because promazine may depress the cough reflex. 

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