Anticholinergics vomiting

The Class I agents have many similar side effects and toxicities. The anticholinergic side effects include dry mouth, constipation, and urinary hesitancy and retention. Common gastrointestinal (GI) side effects include nausea, vomiting, diarrhea, and anorexia. Cardiovascular adverse effects are hypotension, tachycardia, arrhythmias, and myocardial depression, especially in patients with congestive heart failure. Common central nervous system (CNS) side effects are headache, dizziness, mental confusion, hallucinations, CNS stimulation, paraesthesias, and convulsions. 

Dry mouth, blurred vision, urinary hesitancy, urinary retention, nausea, vomiting, palpitations, and headache are some of die adverse reactions that may be seen witii die use of anticholinergic drug (see Chap. 25). 

Nausea and vomiting Gastric dysmotility (surgery, anticholinergic drugs, diabetic gastroparesis) Rapid infusion of hyperosmolar formula... 

The SSRIs produce fewer sedative, anticholinergic, and cardiovascular adverse effects than the TCAs and are less likely to cause weight gain than the TCAs. The primary adverse effects include nausea, vomiting, diarrhea, headache, insomnia, fatigue, and sexual dysfunction. A few patients have anxiety symptoms early in treatment. 

Cyclizine exhibits antihistamine and anticholinergic action and is used for vomiting and diarrhea. The exact mechanism of action is not known. Synonyms of this drug are marezine and migril. 

Pharmacology The mechanism of action of scopolamine in the CNS is not definitely known but may include anticholinergic effects. The ability of scopolamine to prevent motion-induced nausea is believed to be associated with inhibition of vestibular input to the CNS, which results in inhibition of the vomiting reflex. In addition, scopolamine may have a direct action on the vomiting center within the reticular formation of the brain stem. 

In anesthesia drugs from several groups are used as premedication. Pre-anesthetic medication can decrease the anesthetic doses which otherwise would be required to induce anesthesia and so decrease the risk for adverse effects. Pre-anesthetic medication will increase the rate of induction of anesthesia and can reduce pre-operative pain and anxiety. Drugs include benzodiazepines for sedation and their muscle relaxant properties, opiates for pain relieve and anticholinergics or histamine Hi receptor antagonists against nausea and vomiting. Neuroleptics are also used as premedication for their antiemetic effects. 

Geriatric Considerations - Summary Diphenoxylate is an analog of meperidine and can cause opiate adverse effects. When discontinued, physical dependence and withdrawal symptoms can occur. Adverse GI effects such as constipation, nausea/vomit-ing, and abdominal pain may result from normal doses. Afropine is added to discourage abuse but can cause anticholinergic adverse effects in the older adult. The benefits of f his drug combination for older adulfs are limifed by fhe risk of adverse effects. 

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 Apiperazine derivative that competes with histamine for receptor sites in the GI tract, blood vessels, and respiratory tract. May exert CNS depressant activity in subcortical areas. Diminishes vestibular stimulation and depresses labyrinthine function. Therapeutic Effect Produces anxiolytic, anticholinergic, antihista-minic, and analgesic effects relaxes skeletal muscle controls nausea and vomiting. Pharmacokinetics ... 

Parenteral overdose produces a cholinergic crisis manifested as abdominal discomfort or cramps, nausea, vomiting, diarrhea, flushing, facial warmth, excessive salivation, diaphoresis, urinary urgency, and blurred vision. If overdose occurs, stop all anticholinergic drugs and immediately administer 0.6-1.2 mg atropine sulfate IM or IV. 

Mechanism of Action An anticholinergic that reduces excitability of labyrinthine receptors, depressing conduction in the vestibular cerebellar pathway. Therapeutic Effect Prevents motion-induced nausea and vomiting. 

Mechanism of Action An anticholinergic that acts at the chemoreceptor trigger zone in the medulla oblongata. Therapeutic Effect Relieves nausea and vomiting. Pharmacokinetics ... 

Overdose may result in severe anticholinergic effects, such as abdominal pain, nausea and vomiting, confusion, depression, diaphoresis, facial flushing, hypertension, hypotension, respiratory depression, irritability, lacrimation, nervousness,... 

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. 

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. 

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). 

THA overdosage can result in a cholinergic crisis with severe nausea, vomiting, salivation, sweating, bradycardia, hypotension, convulsions, etc. Progressive muscle weakness may result in death from asphyxiation. Treatment with anticholinergics (such as intravenous atropine sulfate) and general supportive treatment are recommended. 

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