VIVA: Pharmacology - Immune system Flashcards
What are the clinical uses of H1 antagonists?
Allergic reactions (e.g. rhinitis, urticaria, possible role in type 1 hypersensitivity)
Motion sickness (best as preventers)
Vestibular disturbance
Nausea and vomiting (especially in pregnancy)
Sedation
Serotonin antagonist (for treatment of serotonin syndrome, e.g. cyproheptadine)
Drug-induced Parkinsonism
What are the major adverse effects of H1 antagonists?
Sedation
Antimuscarinic effects (dry mouth, constipation, urinary retention, blurred vision, delirium, tachycardia)
Seizures
Postural hypotension (due to alpha adrenoceptor blockade)
Drug allergy
What are the significant potential drug interactions with use of H1 antagonists?
Additive effect with other sedatives
Additive effect with muscarinic and alpha-blocking drugs
Grapefruit juice inhibits same P450 group
How are H1 antagonists classified?
1st generation (sedating, e.g. promethazine)
2nd generation (non-sedating, e.g. loratidine)
Describe the pharmacodynamics of promethazine
At least 3 to pass:
- H1 antagonist
- Alpha blockade
- Anticholinergic
- Antidopaminergic
- Antiserotinergic
- Na+ channel blockade
What is passive immunisation?
Transfer of immunity to a host using preformed immunologic products (i.e. immunoglobulin/antibody)
Source may be human or animal
What is passive immunisation useful for?
2 needed to pass:
- Prevention of disease when time does not allow active immunisation (e.g. post-exposure)
- Treatment of disease normally prevented by immunisation (e.g. tetanus)
- In individuals unable to form antibodies (e.g. agammaglobulinaemia)
- For treatment of conditions for which active immunisation is unavailable or not possible (e.g. snakebite)
What passive immunisations might be considered in ED?
Tetanus*
Botulism
Measles
Rubella
Vaccinia
Varicella
HAV, HBV
Diphtheria
Rabies
Rho (D)
Monovalent antivenom (e.g. snake, spider)
Polyvalent snake venom (if species unknown)
- tetanus + one other
