Pharmacokinetics, Pharmacodynamics, Pharmacology of Autonomic nervous system drugs, Autocoids

81.    Succinylcholine:

a.    produces depolarizing neuromuscular blockade.

b.    action is enhanced by parathion.

c.    has long duration of action.

d.    causes flaccid paralysis in chicks.

82.    The following statement(s) about sympathomimetics is / are correct:

a.     sympathetic innervation is necessary for the action of catecholamines.

b.     infusion of noradrenaline increases diastolic and systolic mean blood pressure.

c.     infusion of adrenaline increases pulse rate in man.

d.     non-catechol sympathomimetics  are poor substrates of COMT and MAO.

83.    Catecholamines are used:

a.     to prolong the action of LA.

b.     to treat hyperthyroidism.

c.     in the management of shock.

d.     to treat pulmonary edema.

84.   At sympathetic nerve terminals:

a.     noradrenaline can activate presynaptic alpha1 receptors to inhibit further exocytic release of noradrenaline.

b.     TCAs inhibit membrane uptake mechanism for noradrenaline.

c.     exocytosis of noradrenaline is stimulated by indirectly acting sympathomimetics.

d.     the hydroxylation of tyrosine is regulated by feedback inhibition by noradrenaline.

85.    State true or false:

a.      alpha1 adrenoceptors are more sensitive to isoprenaline than to adrenaline. 

b.      beta1 receptors are more sensitive to isoprenaline than to adrenaline.

c.      alpha2 receptors are more sensitive to noradrenaline than to isoprenaline.

d.      beta2 receptors are more sensitive to noradrenaline than to adrenaline.

86.    State true or false:

a.      amphetamines decrease both diastolic and systolic blood pressure.

b.      the d-isomer of amphetamine is more potent than l-isomer.

c.      the effects of amphetamine on the CNS last only a few minutes.

d.      amphetamine produces reflex tachycardia.

87.    Propranolol and metoprolol have similar:

a.      apparent volume of distribution.

b.      bioavailability.

c.      plasma protein binding.

d.      half-life.

88.    Histamine:

a.      is formed by methylation of histidine.

b.      release from mast cells is stimulated by high concentration of cAMP.

c.      is metabolized mainly to N-methyl imidazole acetic acid.

d.      may be released from storage sites by morphine. 

89.    The distribution of a drug:

a.      from the circulation only involves the free unbound fraction.

b.      into the brain may be more restrictive than into other tissues.

c.      across the placenta only with lipid soluble drugs.

d.      into the intracellular fluid is generally greater for a basic than for an acidic compound.

90.    Succinylcholine:

a.      is used as a muscle relaxant.

b.      is longer-acting than tubocurarine.

c.      depolarizes the nicotinic receptors at the neuromuscular junction.

d.      is rapidly excreted by the kidneys.

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