Atropine dose-dependent effects

The effect of atropine upon chromosomal abnormalities24 has been studied. A significant dose-dependent reduction of heart rate and blood pressure has been observed.25 A possible effectiveness of atropine on Prinzmetal s variant form of... 

Dryness of mucous membranes is a common side effect of anticholinergic drug use and is due to dose-dependent inhibition of glandular secretion. In one study, oral administration of atropine caused tear secretion to fall from 15 to 3 mcl/min.A similar dose of atropine given subcutaneously gave a nearly 50% reduction in lacrimal secretion. Scopolamine at a dose of 1 to 2 mg orally reduced tear secretion from 5 to 0.8 mcl/min. Atropine combined with diphenoxylate (Lomotil) has been reported to cause severe keratoconjimctivitis sicca in susceptible individuals. 

The effect of acetylcholine, dopamine, and bradyki-nin on vascular tone has been examined in interlobular arteries and superficial afferent and efferent arterioles isolated from rabbit kidney [141]. Acetylcholine caused a dose-dependent relaxation of norepinephrine-induced tone in all three vessel types. Significant relaxation was observed with 10(-8) M acetylcholine and higher concentrations caused complete relaxation. In afferent and efferent arterioles dopamine caused a dose-dependent relaxation that was indistinguishable from the one caused by acetylcholine. Dopamine was much less effective on interlobular arteries. In afferent arterioles atropine blocked the effect of acetylcholine, and metoclopramide selectively inhibited dopamine-induced relaxation. Bradykinin caused a dose-dependent relaxation of norepinephrine- induced tone only in efferent arterioles. Bradykinin, either in the bath or lumen, had no effect on the preglomerular microves-... 

Inhibition of AChE by OPs or CBs is one of the few types of toxicity for which there are antidotes. The usual treatment for OP poisoning is atropine and 2-PAM (Table 6). The presence of atropine reduces the effectiveness of the ACh receptors, counterbalancing the excess ACh present. The recommended doses for humans are 1 g 2-PAM Cl (intramuscular or intravenous) two or three times a day and 2 mg atropine (intravenous) at 15-30-min intervals as needed. Higher doses may be used depending on the extent of the OP intoxication. Environmental Health Criteria No. 63 describes the case of a patient who drank a large amount of dicrotophos while inebriated. Treatments were... 

Atropine blocks the effects of acetylcholine in a dose-dependent manner. Thus, the effects of the sympathetic system are seen. At therapeutic doses, tachycardia, increased cardiac output, and an increase in systemic blood pressure may be seen. 

Isolated guinea-pig ileum Serotonin dose-dependently stimulated contractile responses of guinea-pig ileum. Part of this effect is mediated through 5-HTg receptors. The addition of atropine and a 5-HTg receptor antagonist edlowed the study of the specific contribution of 5-HTg receptors. 5-HTg receptor antagonists competively shifted the serotonin response curve to the right. 

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