Respiratory drugs anticholinergics

In general, concomitant drugs with potent anticholinergic (e.g., benztropine) or bone marrow effects (e.g., carbamazepine) should be avoided. Toxicity with BZDs has been reported, including symptoms such as excessive sedation, sialorrhea, ataxia, and, in some instances fainting, loss of consciousness, and respiratory arrest ( 521, 522 and 523). Other potentially significant interactions reported in the literature include ... 

Early signs of tricyclic antidepressant toxicity are due to anticholinergic effects and include tachycardia, mydriasis, dry mouth, low-grade fever, diminished bowel sounds, CNS excitation, and delirium. More serious toxicity is manifested by coma, respiratory depression, seizures, and cardiovascular toxicity including conduction disturbances, hypotension, ventricular arrhythmias, and asystole. Seizures cause hyperthermia, rhabdomyolysis, and metabolic acidosis. Clinical deterioration can be rapid and catastrophic in patients with tricyclic antidepressant overdose. Death most often occurs due to dysrhythmia and circulatory collapse. The typical therapeutic dose of a tricyclic antidepressant is 2-4 mg kg day Doses of 15-20 mg kg are potentially lethal. Therapeutic drug levels for most tricyclic antidepressants range from 100 to... 

The CNS manifestations of tricyclic antidepressant overdose may vary from mild agitation or drowsiness to delirium, coma, respiratory depression, or seizures. These manifestations are thought to result in part from central anticholinergic and antfliistaminic actions of these drugs. 

Because of its potent anticholinergic properties, thioridazine shonld be used cautiously in patients with cardiac diseases snch as congestive heart failure, arrhythmias, angina pectoris, or heart block in encephalitis, Reye s syndrome, head injnry, respiratory disease, epilepsy and other seizure disorders, glaucoma, prostatic hypertrophy, urinary retention, Parkinson s disease, and pheochromocytoma because the drug may exacerbate these conditions and in hypocalcemia because it increases the risk of extrapyramidal reactions. 

Examples (1) A plethora of drug substances , for instance muscle relaxants, sedatives-hypnotics, tricyclic antidepressants, antipsychotic, antihistaminics, and alcohols are observed to interact with opiate analgesics to augment and accelerate their overlapping pharmacological activities, namely anticholinergic effects and respiratory depression. 

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