Augmented pharmacological effect

Type A (augmented) reactions are due to the pharmacological effect of the drug, often in exaggerated form. They are dose related, predictable, and they can occur in anyone. 

The increased myopathy may be due to an additive effect as both neuromuscular blockers and corticosteroids can cause myopathy. Results of an in vitro study suggested that the combination of vecuronium and meth-ylprednisolone might augment pharmacologic denervation, which may lead to myopathy and contribute to the prolonged weakness observed in some critically ill patients. ... 

Traditional Chinese medicine (TCM) postulates seven modes by which natural products can elicit pharmacologic effects, one when an agent is used alone, six when several are used concurrently. In the latter instance, the combined products in a prescription can interact with each other to augment or reduce potency or intrinsic activity with respect to beneficial or harmful effects. The six modes of drug interaction in Traditional Chinese Medicine can be interpreted by modern pharmacological terms 1,2) ... 

In some species, pharmacological effects other than muscle-relaxation may dominate. Thus, as already seen, the activity of S. erichsonii extracts appears to be due primarily to the presence of diaboline derivatives. Leaf extracts have analgesic properties, while stem-bark extracts have spasmolytic properties and augment the activity of the central nervous system (50). The bark alkaloids of S. glabra are reported to have central rather than peripheral effects (Table 1.4, footnote j). Sublethal doses of aqueous extracts from S. castelnaeana cause hypertension, tachycardia, and slight respiratory stimulation enhancement of the hypertension by atropine and its reduction by hexamethonium (mecamylamine) show that the extract has nicotinic activity. Evidently, the toxicity of the plant must be partly due to the tertiary bases it contains (314). 

The toxicity associated with propranolol is for the most part related to its primary pharmacological action, inhibition of the cardiac (3-adrenoceptors. This topic is discussed in detail in Chapter 11. In addition, propranolol exerts direct cardiac depressant effects that become manifest when the drug is administered rapidly by the IV route. Glucagon immediately reverses all cardiac depressant effects of propranolol, and its use is associated with a minimum of side effects. The inotropic agents amrinone (Inocor) and milrinone (Primacor) provide alternative means of augmenting cardiac contractile function in the presence of -adrenoceptor blockade (see Chapter 15). Propranolol may also stimulate bron-chospasm in patients with asthma. 

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