Pharmacology Flashcards
Inheritance of acute intermittent porphyria
Autosomal dominant (defect in porphobilinogen deamine - enzyme involved in biosynthesis of haem)
Presentation of acute intermittent porphyria
Neuropsychiatric/abdominal symptoms in 20-40 year olds
Sedation in someone with acute intermittent porphyria
Chlorpromazine - NOT diazepam
Drugs that could precipitate acute intermittent porphyria
Barbiturates, benzos, alcohol, OCP, sulphonamides
Management of accidental adrenaline injection
Phentolamine (short acting alpha blocker)
Effects of adrenaline
Very similar to DKA - hyperglycaemia (mostly alpha adrenergic response), inhibits insulin secretion, increased lactate by adipose tissue
What is used for alcohol abstinence?
Disulfuram (inhibition acetaldehyde)
Contraindication to disulfuram use
Psychosis, IHD
What can be used to reduce alcohol cravings
Acamprostate - weak antagonist of NMDA
MOA allopurinol
Inhibits xanthine oxidase
What drugs used in acute gout attack
Clochicine/NSAIDs/steroids
Who is at increased risk of gout?
Ethnic minotirites
What allele should be screened for in gout in ethnic minorities?
HLA B 5801
Key drug interactions allopurinol
Azathioprine (25% dose reduction - allopurinol increases active compound due to 6-mercaptopurine), cyclophosphamide (decreased renal clearance), theophylline (inhibits breakdown)
Adrenoreceptor agonists acting on alpha-1
Phenylephrine eg eyedrops, hypotension
Adrenoreceptor agonists acting on alpha-2
Clonidine (menopause, HTN)
Adrenoreceptor agonists acting on beta-1
Dobutamine eg inotrope
Adrenoreceptor agonists acting on beta-2
Salbutamol
Adrenoreceptor agonists acting on beta-3
Being developed, role in obesity
Key roles alpha 1 adrenoreceptors
Vasoconstriction, salivary secretion, hepatic gluconeogenesis
Key roles alpha 2 adrenoreceptors
Mainly pre-synaptic inhibition, inhibits insulin, platelet aggregation
Key role beta adrenoreceptors
Mainly located in heart - increase HR and force, vasodilation, lipolysis
Adrenoreceptor antagonists acting on alpha
Alpha 1 - doxazosin, 1a tamsulosin, 2 yohimbine, non selective - phenoxybenzamine, carvedilol, labetalol
Adrenoreceptor antagonists acting on beta
B1 Atenolol, non selective propranolol