04 Drugs affecting the immune response Flashcards
4.01 CALCINEURIN INHIBITORS
Immunosuppressants: ciclosporin, tacrolimus, pimecrolimus - actions
binding to cytosolic immunophilins to form a complex that inhibits calcineurin
this reduces activation and proliferation of T cells and production of cytokines
4.01 CALCINEURIN INHIBITORS
Immunosuppressants: ciclosporin, tacrolimus, pimecrolimus - MOA
inhibits calcineurin (calcium-dependent phosphatase) which normally activates the transcription of interleukin-2 (IL-2)
4.01 CALCINEURIN INHIBITORS
Immunosuppressants: ciclosporin, tacrolimus, pimecrolimus - abs/distrib/elim
ciclosporin and tacrolimus can be given orally or by IV infusion, metabolised in the liver by the P450 3A enzyme system
topical formulations of tacrolimus and pimecrolimus have low systemic absorption
4.01 CALCINEURIN INHIBITORS
Immunosuppressants: ciclosporin, tacrolimus, pimecrolimus - clinical use
used to prevent rejection of organ and tissue transplants and for prevention of graft v host disease
can be useful in autoimmune diseases
topical use for atopic dermatitis (tacrolimus or pimecrolimus)
4.01 CALCINEURIN INHIBITORS
Immunosuppressants: ciclosporin, tacrolimus, pimecrolimus - adverse effects
myelosuppression and risk of infection
nephrotoxicity
can cause hypertension, hepatotoxicity, tremor, paraesthesia
4.02 ANTIPROLIFERATIVE IMMUNOSUPPRESSANT
Azathioprine - actions
reduces the clonal proliferation of T and B cells during the induction phase of the immune response
4.02 ANTIPROLIFERATIVE IMMUNOSUPPRESSANT
Azathioprine - MOA
interferes with purine synthesis and has cytotoxic action on dividing cells
4.02 ANTIPROFILERATIVE IMMUNOSUPPRESSANT
Azathioprine - abs/distrib/elim
given orally or by IV infusion
metabolised to mercaptopurine, which is the cytotoxic moiety acting by interfering with purine nucleotide metabolism
mercaptopurine is inactivated by xanthine oxidase
4.02 ANTIPROLIFERATIVE IMMUNOSUPPRESSANT
Azathioprine - clinical use
used to prevent rejection of organ and tissue transplants and for prevention of graft v host disease
also used in chronic inflammatory and autoimmune diseases (e.g. rheumatoid arthritis, inflammatory bowel disease)
4.02 ANTIPROLIFERATIVE IMMUNOSUPPRESSANT
Azathioprine - adverse effects
myelotoxicity (dose-related - monitoring is required)
GIT disturbances, hypersensitivity reactions (skin rashes, arthralgia, etc.)
4.03 ANTIPROLIFERATIVE IMMUNOSUPPRESSANT
Mycophenolate mofetil - actions
selectively restrains the clonal proliferation of T and B cells and reduces the production of cytotoxic T cells
4.03 ANTIPROLIFERATIVE IMMUNOSUPPRESSANT
Mycophenolate mofetil - MOA
selectively inhibits inosine monophosphate dehydrogenase which is responsible for de novo purine synthesis specifically in T and B lymphocytes (other cells can generate purines by another pathway)
4.03 ANTIPROLIFERATIVE IMMUNOSUPPRESSANT
Mycophenolate mofetil - abs/distrib/elim
given orally or by IV infusion
metabolised to mycophenolic acid which is the active moiety
4.03 ANTIPROLIFERATIVE IMMUNOSUPPRESSANT
Mycophenolate mofetil - clinical use
used to prevent rejection of organ transplants, usually in combination with ciclosporin and glucocorticoids
also used in a wider range of autoimmune diseases (e.g. lupus, vasculitis)
4.03 ANTIPROLIFERATIVE IMMUNOSUPPRESSANT
Mycophenolate mofetil - adverse effects
GIT, CVS and respiratory system disturbances
hepatitis, pancreatitis
tremor, dizziness
flu-like syndrome
4.04 ANTIPROLIFERATIVE ANTIBIOTIC
Sirolimus (rapamycin) - actions
inhibits the clonal proliferation of T and (more particularly) B cells
decreases immunoglobulin production
4.04 ANTIPROFILERATIVE ANTIBIOTIC
Sirolimus (rapamycin) - MOA
blocks the response of precursor cells to interleukin-2 (IL-2) by binding to a cytosolic protein (FK-binding protein 12) to form a complex that inhibits the activation of mammalian target of rapamycin (mTOR) kinase - thus suppressing activation of T and B cells
4.04 ANTIPROLIFERATIVE ANTIBIOTIC
Sirolimus (rapamycin) - abs/distrib/elim
given orally
metabolised by P450 3A in the liver - therefore many drug interactions
4.04 ANTIPROLIFERATIVE ANTIBIOTIC
Sirolimus (rapamycin) - clinical use
used to prevent rejection of organ transplants (particularly renal because, unlike ciclosporin, it has no renal toxicity) usually in combination with ciclosporin or glucocorticoids
4.04 ANTIPROLIFERATIVE ANTIBIOTIC
Sirolimus (rapamycin) - adverse effects
myelosuppression (important)
hyperlipidaemia
venous thromboembolism
diarrhoea
rash
osteonecrosis
4.05 GLUCOCORTICOIDS
Prednisolone, dexamethasone, hydrocortisone, triamcinolone - actions
inhibits the clonal proliferation of T and B cells and macrophage activation
(other actions: reduces chronic inflammation, autoimmune and hypersensitivity reactions, various metabolic effects, negative feedback action on anterior pituitary and hypothalamus)
4.05 GLUCOCORTICOIDS
Prednisolone, dexamethasone, hydrocortisone, triamcinolone - MOA
glucocorticoids (GCs) interact with intracellular receptors to inhibit the transcription of specific genes that code for various cytokines esp. IL-2
4.05 GLUCOCORTICOIDS
Prednisolone, dexamethasone, hydrocortisone, triamcinolone - abs/distrib/elim
given orally, by injection or topically
the main effects occur only after 2-8h because protein synthesis of mediators and enzymes is required
4.05 GLUCOCORTICOIDS
Prednisolone, dexamethasone, hydrocortisone, triamcinolone - clinical use
to prevent rejection of organ transplants and to treat rejection episodes
also used for a wide range of inflammatory, hypersensitivity and autoimmune conditions
4.05 GLUCOCORTICOIDS
Prednisolone, dexamethasone, hydrocortisone, triamcinolone - adverse effects
used long term it causes:
suppression of response to infection
suppression of endogenous GC synthesis
osteoporosis
growth suppression in children
iatrogenic Cushing’s syndrome
4.06 TNF INHIBITORS
Infliximab, adalimumab, etanercept, golimumab - actions
wide-ranging immunosuppressant effects
4.06 TNF INHIBITORS
Infliximab, adalimumab, etanercept, golimumab - MOA
monoclonal antibody against tumour necrosis factor (TNF)-α that binds with the TNF-α and prevents its interaction with cell surface receptors in inflammatory cells
4.06 TNF INHIBITORS
Infliximab, adalimumab, etanercept, golimumab - abs/distrib/elim
given IV or SC
etanercept is given twice a week, whereas the frequency of injection for the others varies from 4-8 weeks
4.06 TNF INHIBITORS
Infliximab, adalimumab, etanercept, golimumab - clinical use
rheumatoid arthritis
inflammatory bowel disease
psoriasis
ankylosing spondylitis
4.06 TNF INHIBITORS
Infliximab, adalimumab, etanercept, golimumab - adverse effects
nausea, vomiting
headache
upper respiratory tract infections
because of inactivation of macrophages, latent TB and other serious infections may recur
blood dyscrasias
4.07 ANTIBODIES AGAINST CD20
Rituximab, ofatumumab, ocrelizumab - actions
immunosuppressant
antineoplastic
4.07 ANTIBODIES AGAINST CD20
Rituximab, ofatumumab, ocrelizumab - MOA
binding to the CD20 antigen on B lymphocytes results in cell lysis and apoptosis
4.07 ANTIBODIES AGAINST CD20
Rituximab, ofatumumab, ocrelizumab - abs/distrib/elim
given IV
4.07 ANTIBODIES AGAINST CD20
Rituximab, ofatumumab, ocrelizumab - clinical use
rituximab or ofatumumab - lymphoma and leukaemia
rituximab is widely used for rheumatoid arthritis and vasculitis
ocrelizumab - multiple sclerosis
4.07 ANTIBODIES AGAINST CD20
Rituximab, ofatumumab, ocrelizumab - adverse effects
neutropenia
infections
4.08 MONOCLONAL ANTIBODIES (NON-CD20)
Alemtuzumab
drug target - CD52 antigen
MS and haematological malignancies
4.08 MONOCLONAL ANTIBODIES (NON-CD20)
Brentuximab
drug target - CD30 antigen
used in lymphoma
4.08 MONOCLONAL ANTIBODIES (NON-CD20)
Belimumab
drug target - B-lymphocyte stimulator protein
used for lupus erythematosus
4.08 MONOCLONAL ANTIBODIES (NON-CD20)
Vedolizumab, natalizumab
drug target - α4 integrin
vedolizumab is directed at T-helper lymphocytes that home in on the gut and is used in inflammatory bowel disease
natalizumab is used in MS
4.09 INTERLEUKIN INHIBITORS
Anakinra
drug target - IL-1
used for rheumatoid arthritis
4.09 INTERLEUKIN INHIBITORS
Tocilizumab
drug target - IL-6
used for rheumatoid arthritis and giant cell arteritis
4.09 INTERLEUKIN INHIBITORS
Secukinumab
drug target - IL-17
used for psoriasis, psoriatic arthritis and ankylosing spondylitis
4.09 INTERLEUKIN INHIBITORS
Ustekinumab
drug target - IL-12 and 23
used for psoriasis, psoriatic arthritis and Crohn’s disease
4.10 JAK
Monoclonal antibodies targeting JAK: tofacitinib, baricitinib - actions
attenuates immune and inflammatory response
4.10 JAK
Monoclonal antibodies targeting JAK: tofacitinib, baricitinib - MOA
inhibits Janus kinase (JAK) and interrupts intracellular signalling involved in cytokine and interferon release
4.10 JAK
Monoclonal antibodies targeting JAK: tofacitinib, baricitinib - abs/distrib/elim
given orally
good bioavailability
metabolised mainly by CYP3A4
4.10 JAK
Monoclonal antibodies targeting JAK: tofacitinib, baricitinib - clinical use
mainly in rheumatoid arthritis
tofacitinib may be used for psoriatic arthritis and ulcerative colitis
4.10 JAK
Monoclonal antibodies targeting JAK: tofacitinib, baricitinib - adverse effects
serious infections, nausea, upper respiratory tract symptoms
4.11 NON-SEDATING ANTIHISTAMINES
Cetirizine, loratadine, fexofenadine, azelastine - actions
inhibits H1 receptor actions and thus reduces immediate hypersensitivity reactions
4.11 NON-SEDATING ANTIHISTAMINES
Cetirizine, loratadine, fexofenadine, azelastine - MOA
competitive inhibitor of histamine at H1 receptors on smooth muscle
4.11 NON-SEDATING ANTIHISTAMINES
Cetirizine, loratadine, fexofenadine, azelastine - abs/distrib/elim
given orally, well absorbed
metabolised in the liver
excreted in the urine
does not cross the blood-brain barrier, so no sedative adverse effect
4.11 NON-SEDATING ANTIHISTAMINES
Cetirizine, loratadine, fexofenadine, azelastine - clinical use
hypersensitivity reactions: hay fever, urticaria, some drug allergies, insect bites, pruritus
4.11 NON-SEDATING ANTIHISTAMINES
Cetirizine, loratadine, fexofenadine, azelastine - adverse effects
anticholinergic action on peripheral muscarinic receptors (dry mouth, sometimes blurred vision, constipation, urine retention)
4.12 SEDATING ANTIHISTAMINES
Promethazine, cyclizine, cinnarizine, chlorphenamine, etc. - actions
inhibits H1 receptor actions and thus reduces immediate hypersensitivity reactions
has anticholinergic action, some local anaesthetic action, weak α-adrenoceptor antagonism and fairly marked sedative effect
CNS effects on the vestibular nuclei and vomiting centre
4.12 SEDATING ANTIHISTAMINES
Promethazine, cyclizine, cinnarizine, chlorphenamine, etc. - MOA
competitive inhibitor of histamine at H1 receptors on smooth muscle, CNS, etc.
4.12 SEDATING ANTIHISTAMINES
Promethazine, cyclizine, cinnarizine, chlorphenamine, etc. - abs/distrib/elim
given orally or by injection
enters the CNS
4.12 SEDATING ANTIHISTAMINES
Promethazine, cyclizine, cinnarizine, chlorphenamine, etc. - clinical use
promethazine, cyclizine, cinnarizine: nausea and vomiting, motion sickness
chlorphenamine, hydroxyzine: hypersensitivity reactions (hay fever, urticaria), premedication, sedation, emergency treatment of anaphylaxis
4.12 SEDATING ANTIHISTAMINES
Promethazine, cyclizine, cinnarizine, chlorphenamine, etc. - adverse effects
anticholinergic action on peripheral muscarinic receptors (dry mouth, sometimes blurred vision, constipation, urine retention)
headache
drowsiness
4.13 What antihistamines are used for motion sickness?
antihistamines: promethazine, cyclizine, cinnarizine
hyoscine - a muscarinic antagonist, given orally or by transdermal patch