Phenothiazines Tricyclic antidepressants

Diphenhydramine, trihexiphenidyl, tricyclic antidepressants, phenothiazines, and lithium... 

A number of drugs in addition to atropine and scopolamine have antimuscarinic properties. Tbese include tricyclic antidepressants, phenothiazines, and antihistamines. Physostigmine has been used in the treatment of acute toxicity produced by these compounds. However, physostigmine can produce cardiac arrhythmias and other serious toxic effects of its own, and therefore, it should be considered as an antidote only in life-threatening cases of anticholinergic drug overdose. 

Because neuronal uptake is necessary for the hypotensive activity of guanethidine, drugs that block the catecholamine uptake process or displace amines from the nerve terminal (see Chapter 6) block its effects. These include cocaine, amphetamine, tricyclic antidepressants, phenothiazines, and phenoxybenzamine. 

Another problem which can compromise compliance concerns the hypotensive actions of many psychotropic drugs (e.g. tricyclic antidepressants, phenothiazine neuroleptics). Due to the alphaj receptor antagonistic action of these drugs, they are likely to cause severe orthostatic... 

Tricyclic antidepressants + phenothiazines —> additive anticholinergic effects that can cause psychosis and agitation. 

Rare, familial hyperthermia (41 °C) associated with inhalation anaesthetics, muscle relaxants, tricyclic antidepressants, phenothiazine neuroleptics (particularly chlorpromazine) monoamine oxidase inhibitors and haloperidol. 

Anesthetics, antihistamines, barbiturates, benzodiazepines, chloral hydrate, meprobamate, narcotics, phenothiazines, tricyclic antidepressants Phenothiazines Diazepam... 

All the major oxidative mechanisms can be illustrated by considering the metabolism of the barbiturates, benzodiazepines, amphetamines, tricyclic antidepressants, phenothiazines, and opiates. 

Tobacco smoke reduces serum levels of a wide range of drugs and dose adjustment may be necessary when smokers have given up, particularly with theophylline, beta-blockers, adrenergic agonists, nifedipine, tricyclic antidepressants, phenothiazines, benzodiazepines and insulin. 

Xerostomia caused by drugs (e.g., tricyclic antidepressants, phenothiazine) and chemotherapy, radiotherapy to head-neck and various diseases, e.g., Sjogren s syndrome, HIV, cancer of head-neck, bone marrow transplant recipients Smoking... 

B. Toxicodynamics Toxicodynamics is a term used to denote the injurious effects of toxins, ie, their pharmacodynamics. A knowledge of toxicodynamics can be useful in the diagnosis and management of poisoning. For example, hypertension and tachycardia are typically seen in overdoses with amphetamines, cocaine, and antimuscarinic drugs. Hypotension with bradycardia occurs with overdoses of calcium channel blockers, beta-blockers, and sedative-hypnotics. Hypotension with tachycardia occurs with tricyclic antidepressants, phenothiazines, and theophylline. Hyperthermia is most frequently a result of overdose of drugs with antimuscarinic actions, the salicylates, or sympathomimetics. Hypothermia is more likely to occur with toxic doses of ethanol and other CNS depressants. Increased respiratory rate is often a feature of... 

Opioids (especially methadone and heroin) are the most common cause of serious neonatal drug withdrawal symptoms. Other dmgs for which a withdrawal syndrome has been reported include phencyclidine (POP), cocaine, amphetamines, tricyclic antidepressants, phenothiazines, benzodiazepines, barbiturates, ethanol, clonidine, diphenhydramine, lithium, meprobamate, and theophylline. A careful dmg history from the mother should include illicit drugs, alcohol, and prescription and over-the-counter medications, and whether she is breast-feeding. 

Ethch1orvyno1 Acetylsalicylic acid. Paracetamol, Propoxyphene Diphenylhydantoin Benzodiazepines, Meprobamate, Tricyclic antidepressives, Phenothiazines, Antihistamines Alcohols, Narcotics, Chloral hydrate, Hezapropymate, Fe, Li Phthalates and Adipate, and further plasticizers and vacutainer contents. Fatty acids and -esters. Cholesterol, Squalene (in saliva)... 

To anticipate briefly, shortening the length of the side chain in the phenothiazines from three to two carbon atoms changes I he activity of the products from neuroleptics to antihistaminic iigents. A rather similar effect is seen in the tricyclic antidepressants. Reaction of ketone, 27, with the Grignard reagent I rom 4-chloro-l-methylpipyridine (35) affords the tertiary alco-liol, 36. Dehydration gives the antihistamine, cyproheptadine (37). ... 

Amantadine is used cautiously in patients with seizure disorders, psychiatric problems, renal impairment, and cardiac disease. Amantadine is a Pregnancy Category B drug and is used cautiously during pregnancy and lactation. Concurrent use of antihistamines, phenothiazines, tricyclic antidepressants, disopyramide, and quinidine may increase the anticholinergic effects (dry mouth, blurred vision, constipation) of amantadine... 

Administration of atropine with meperidine (Demerol), flurazepam (Dalmane), diphenhydramine (Benadryl), phenothiazines, and the tricyclic antidepressants may increase the effects of atropine. There is a decreased effectiveness of haloperidol when administered with the anticholinergic dragp. 

The tricyclic antidepressants (TCAs) derive their name from their three-ringed molecular structure (Fig. 20.3) and emerged, in 1958, from a search for better neuroleptics than chlopromazine among the phenothiazines. The prototype, imipramine, turned out to be ineffective in treating the positive symptoms experienced by schizophrenics but it did relieve their depression (negative symptoms). In fact, imipramine is still the standard agent against which novel antidepressants are compared in clinical trials. 

Medications (analgesics, anticholinergerics, calcium channel blockers, clonidine, diuretics, phenothiazines, tricyclic antidepressants, iron supplements, calcium- and aluminum-containing antacids)... 

Tricyclic antidepressants Monoamine oxidase inhibitors Selective serotonin reuptake inhibitors Antipsychotics Phenothiazines Risperidone Lithium... 

Drugs that block the catecholamine uptake process (e.g., cocaine, tricyclic antidepressants, and phenothiazines) are apt to block the anti hypertensive action of which of the following drugs ... 

Decreased cigarette consumption in smokers, easier to stop smoking Exaggerated response to warfarin and phenytoin Increased efficacy of omeprazole, increased toxicity of mephenytoin Absence of codeine efficacy, no effect of encainide, increased levels of tricyclic antidepressants, fluoxetine, phenothiazines Sustained paralysis to succinylcholine, possible increased toxicity of cocaine Unknown... 

The most frequent and widely used drugs for treating endogenous depression are tricyclic antidepressants. In terms of clinical action they are similar to the phenothiazine... 

Tricyclic antidepressants are chemically, pharmacologically, and toxicologically very similar to antipsychotics of the phenothiazine series. The mechanism of action of tricyclic depressants is not conclusively known, and not one of the proposed hypotheses is currently capable of fully explaining their antidepressant effect. 

Pharmacology The tricyclic antidepressants (TCAs), structurally related to the phenothiazine antipsychotic agents, possess 3 major pharmacologic actions in varying degrees Blocking of the amine pump, sedation, and peripheral and central... 

Drugs that may be affected by duloxetine include drugs extensively metabolized by CYP2D6 (eg, flecainide, phenothiazines, propafenone, tricyclic antidepressants, thioridazine), alcohol, CNS-acting drugs, MAOIs, and drugs highly bound to plasma proteins (eg, warfarin). 

Drugs that may be affected by SSRIs Drugs that may be affected by SSRIs include alcohol, benzodiazepines, beta blockers, buspirone, carbamazepine, cisapride, clozapine, cyclosporine, diltiazem, digoxin, haloperidol, hydantoins, lithium, methadone, mexiletine, nonsedating antihistamines, NSAIDs, olanzapine, phenothiazines, phenytoin, pimozide, procyclidine, ritonavir, ropivacaine, sumatriptan, sulfonylureas, sympathomimetics, tacrine, theophylline, tolbutamide, tricyclic antidepressants, and warfarin. 

Drugs that may be affected by lithium include phenothiazines, sympathomimetics, iodide salts, neuromuscular blocking agents, and tricyclic antidepressants. 

Drugs that may interact with Gl anticholinergics include amantadine, atenolol, digoxin, phenothiazines, and tricyclic antidepressants. 

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