801.Which of the following is true of aspirin
A.There is more of the unionized form in acid environment
B.It inhibits lipooxygenase
C.At normal analgesic doses it decreases plasma uric acid levels
D.In OD there is initial metabolic acidosis
E.It decrease the effect of tolbutamide

A.decreases plasma levels of phenytoin
B.increases the activity of spironolactone
C.will cause penicillin G level in plasma to reduce
D.inhibits the uricosuric effect of probenecid
E.toxicity will be enhanced by acetazolamide

803.the toxic effect of paracetamol
A.can be avoided using cimetidine to inhibit cytochrome P450 system
B.are always evident with doses of 150mg/kg and greater
C.in chronic OD are less likely than in acute OD
D.include neurotoxicity resulting in personality changes
E.occur because sulfation/glucuronidation pathways and metabolism are saturable

A.Is a IIaIIIb antagonist
B.Has a high affinity for the COX 1 receptor
C.Inhibits PG synthesis in the stomach and SI
D.Has minimal antiplatelet action
E.Is beneficial in secondary stroke prevention

805.The heteroacetyl acetic group of NSAIDs include all except

A.arrests cell mitosis in anaphase
B.causes the release of HA from mast cells
C.inhibits the movement of melanin granules in melanophores
D.is mainly excreted in the urine
E.should never be administered IV

807.All are NSAIDS except

808.Common effects of inhalational general anaesthetics include
A.Increased mean BP
B.Increased tidal V of respiration
C.Increased metabolic rate of brain
D.Increased cerebral blood flow
E.Increased hepatic blood flow

809.Regarding local anaesthetics, which is false
A.They have a high affinity for sodium channels in the resting state
B.They are antagonized by an elevated extracellular calcium
C.They are enhanced by raised extracellular K+
D.They block myelinated fibres before unmyelinated fibres of the same diameter
E.They preferentially block small nerve fibres

810.Regarding N2O which is true
A.It can be used safely in patients with bowel obstruction
B.It is a useful analgesic in patients with decompression illness
C.It is mainly metabolized by the liver
D.It results in megaloblastic anaemia if used for prolonged periods
E.It is effective due to its high blood solubility