Antihistamines nausea

This compound has antihistaminic activity and is usehil in the therapy of motion sickness. It may also be effective in the control of post-operative nausea and vomiting. It is classified as FDA Category B for Pregnancy, ie, no demonstrated risks shown in animal studies however, no controlled trials in pregnant women. Large doses may cause drowsiness and dry mouth owing to decreased secretion of saUva. 

Use of codeine may result in respiratory depression, euphoria, light-headedness, sedation, nausea, vomiting, and hypersensitivity reactions. The more common adverse reactions associated with the antitussives are listed in the Summary Drug Table Antitussive, Mucolytic, and Expectorant Drugs. When used as directed, nonprescription cough medicines containing two or more ingredients have few adverse reactions. However, those that contain an antihistamine may cause drowsiness. 

Antihistamines are commonly used to prevent and treat nausea and vomiting due to motion sickness, vertigo, or migraine headache.1,17 Their efficacy is presumably due to the high concentration of histamine (Hx) and muscarinic cholinergic receptors within the vestibular system. Similarly to scopolamine, antihistamines such as diphenhydramine and... 

Hydration, heating pads, relaxation, and distraction Stool softener and/or stimulants for constipation Antihistamine for itching Antiemetics for nausea or vomiting... 

Beneficial therapy for patients with nausea and vomiting associated with disorders of balance can reliably be found among the antihistaminic-... 

Domperidone is a dopamine antagonist that acts on the chemoreceptor trigger zone. It can therefore be used as an anti-emetic in nausea and vomiting, for example, to counteract side-effects of cytotoxic therapy and to treat nausea associated with dopaminergic drugs used in Parkinson s disease. Unlike hyoscine butlybromide and antihistamines, domperidone is ineffective in motion sickness. 

Its most important adverse effects are nephrotoxicity and ototoxicity. The risks for nephrotoxicity can be limited by adequate hydration. Marked nausea and vomiting are frequent. Only mild-to-moderate myelosuppression is seen. Pseudo-allergic reactions may occur which respond to intravenous epinephrine and corticosteroids or antihistamines. 

As first choice treatment a well-established antihistamine such as meclozine is recommended. Promethazine is another antihistamine which reduces nausea, but sedation is a not always desired adverse effect. Metoclopramide increases intestinal motility and could be used short term also early in pregnancy. A neuroleptic such as prochlorperazine reduces nausea but should only be used for shortterm treatment due to the risk of extrapyramidal adverse reactions. Serotonin receptor antagonists can be used in post-operahve nausea and during treatment with cytostatics. 

Mechanism of Action A phenothiazine that blocks dopamine neurotransmission at postsynaptic dopamine receptor sites. Possesses strong anticholinergic, sedative, and antiemetic effects moderate extrapyramidal effects and slight antihistamine action. Therapeutic Effect Relieves nausea and vomiting improves psychotic conditions controls intractable hiccups and porphyria. 

Mechanism of Action A phenothiazine that acts as an antihistamine, antiemetic, and CNS-antipsychotiC typical hypnotic. As an antihistamine, inhibits histamine at histamine receptor sites. As an antiemetic, diminishes vestibular stimulation, depresses labyrinthine function, and acts on the chemoreceptor trigger zone. As a sedative-hypnotic, produces CNS depression by decreasing stimulation to the brainstem reticular formation. Therapeutic Effect Prevents allergic responses mediated by histamine, such as rhinitis, urticaria, and pruritus. Prevents and relieves nausea and vomiting. Pharmacokinetics ... 

The same molecules used to treat allergies and cold symptoms have many other uses. Antihistamines are particularly effective as antiemetics in suppressing nausea associated with gastrointestinal illnesses. They can also be used to treat the symptoms of motion sickness or even vestibular disturbances (vertigo). Because of their ability to induce sedation, antihistamines are widely used in over-the-counter sleep aids. 

CNS disorders Scopolamine and hyoscine are effectively used in the treatment of nausea, vomiting and motion sickness. Centrally acting anticholinergic/ antihistaminics e.g. trihexyphenidyl are used in parkinsonism. 

It is a cromolyn analogue. It is an antihistaminic (H antagonist) and probably inhibits airway inflammation induced by platelet activating factor (PAF) in primate. It is not a bronchodilator. It is used in asthma and symptomatic relief in atopic dermatitis, rhinitis, conjunctivitis and urticaria. It is absorbed orally and well tolerated. Bioavailability is 50% due to first pass metabolism and is primarily metabolized. The common side effects include dry mouth, sedation, dizziness and nausea. 

Cyclizine has antimuscarinic properties and is a potent anti-emetic, effective for the control of postoperative and drug-induced nausea and vomiting. It has been used to prevent motion sickness, although diphenhydramine and promethazine are more effective. It is available in oral and parenteral formulations. In contrast to many other first-generation antihistamines sedation is not marked. It is available in tablet form as the hydrochloride and in injectable form as the lactate. Because of its anticholinergic action, blurred vision and dry mouth are associated with clinical doses. When given by rapid intravenous injection tachycardia may be a problem. Meclozine is a related drug which, like cyclizine, is used primarily for motion sickness. 

Substituted benzamides include metodopramide (discussed previously) and trimethobenzamide. Their primary mechanism of antiemetic action is believed to be dopamine-receptor blockade. Trimethobenzamide also has weak antihistaminic activity. For prevention and treatment of nausea and vomiting, metodopramide may be given in the relatively high dosage of 10-20 mg orally or intravenously every 6 hours. The usual dose of trimethobenzamide is 250 mg orally, 200 mg rectally, or 200 mg by intramuscular injection. The principal adverse effects of these central dopamine antagonists are extrapyramidal restlessness, dystonias, and parkinsonian symptoms. 

Sometimes secondary effects can be used therapeutically. Antihistamines, for example, have as their primary effect the alleviation of an immune response. Secondarily, they cause drowsiness and reduce nausea associated with motion. Over-the-counter sleep aides and antinausea preparations contain antihistamines such as dimenhydrinate... 

Anticholinergics are associated with many side effects including mood change, confusion, hallucinations, drowsiness, and cardiac irregularity.13,39 In addition, blurred vision, dryness of the mouth, nausea/ vomiting, constipation, and urinary retention are fairly common. Antihistamine drugs with anticholinergic properties are also used occasionally (Table 10-2). 

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