P450 enzyme system

P450 enzyme system

Induction usually requires prolonged exposure to the inducing drug, as opposed to P450 inhibitors, where effects are often seen rapidly

Inducers of the P450 system include

antiepileptics: phenytoin, carbamazepine
barbiturates: phenobarbitone
St John’s Wort
chronic alcohol intake
smoking (affects CYP1A2, reason why smokers require more aminophylline)

Inhibitors of the P450 system include

antibiotics: ciprofloxacin, erythromycin
cimetidine, omeprazole
imidazoles: ketoconazole, fluconazole
SSRIs: fluoxetine, sertraline
sodium valproate
acute alcohol intake

Most common cause of post operative arrhythmia
Aspiration pneumonia
Electrolytes imbalance

Most common pulmonary complication post operative …

insulin used in DKA
A short acting
B rapid acting
C long actting

which is contraindicated in renal insufficiency
A metformin
B glipizide
C pioglitazone
D miglitol
E none

Choose the correct diagnosis for this ECG:
A. 1st Degree AV Block
B. Type I 2nd Degree AV Block
C. Type II 2nd Degree AV Block
D. 3rd Degree AV Block
E. Sinus arrhythmia

A 45 year old patient presents with proximal muscle weakness, particularly in the lower limbs. She has a heliotropic rash around the eyes and also Gottron’s papules. Which one of the following antibodies is most strongly associated? (Please explain, this from me​:stuck_out_tongue_winking_eye::stuck_out_tongue_winking_eye:)
A. La
B. Ro
C. Jo-1
D. SCL-70
E. Anti DsDNA

A 30-year-old woman with primary pulmonary hypertension asks you some questions regarding treatment options. She is awaiting transfer to a specialist centre for right heart catheterisation.

Which of the following is true?

She will be able to have children, as long as she is carefully monitored

She will benefit from taking lisinopril

She will benefit from taking long-term anticoagulation with warfarin

She will benefit from taking the oral contraceptive pill

She will benefit from taking verapamil

A 39-year-old patient is taking phenelzine, a monoamine oxidase inhibitor, for the treatment of depression. Which one of the following foods can the patient safely eat?

A. Bovril
B. Cheese
C. Oxo
D. Eggs
E. Broad beans

A 19-year-old man presents to the Emergency Department 5 hours ingesting 20g of paracetamol. N-acetyl cysteine is started straight away. What is the mechanism of action of N-acetyl cysteine?

A.Replenishes glutathione
B.Inhibits P450 mixed function oxidases
C.Replenishes glucuronic acid
D.Promotes formation of N-acetyl-B-benzoquinone imine
E.Neutralises mercapturic acid

Interesting question :
An 83 year old man presents to his GP with six month history of fatigue and increasing exertional dyspnoea.
Investigations shows:
Hb 7.5 g/dl
MCV 112 fl
WBCs 3.1
Neutrophil 34%
Blast 1%
PLT 12*109
Bone marrow aspirations stained with perl’s stains shows ring sideroblasts.
What the most likely diagnosis?
A aplastic anaemia
C metastatic bone marrow infiltration
D myelodysplastic syndrome
E myelofibrosis