Rheum Pharmaco Flashcards
What are the MOA of hydroxychloroquine in SLE?
- By↑ cellular pH, inhibits Toll-like receptor mediated activation of the innate immune system -> inhibition of IFN-a expression and thereby prevents activation of multiple IFN-α-mediated pathways and resultant widespread inflammatory damage
- Anti-thrombotic
- Anti-lipidemic
What is the MOA and indications of cyclophosphamide?
Uses
- Remission induction in SLE/CTD with major organ involvement
- Myeloablative: cancer treatment (requires different dosage)
Mechanism of action: - Alkylating agent; inhibits DNA synthesis, hence Cytotoxic!
What are the common adverse reactions of cyclophosphamide?
Common adverse reactions
- GI: nausea, vomiting
- Haematological: myelosuppresive (leukopenia, pancytopaenia)
- Bladder toxicity: haemorrhagic cystitis/bladder cancer (due to renally excreted toxic metabolites \r)
- Ovarian failure, subfertility/ sterility. Sperm storage, oocyte preservation in adults of child-bearing age
- Teratogenicity
Opportunistic infections & Reactivation of Latent infections
- Reactivation: Herpes Zoster, HSV, EBV, CMV, Tb, Hep B
- Pneumocystis Jirovecii (give prophylactic co-trimoxazole)
Dose adjustment in renal impairment
What is the MOA and indication of Mycophenolate mofetil (MMF)?
Remission induction or maintenance in SLE/CTD with major organ involvement e.g. diffuse proliferative lupus nephritis in women of child-bearing age (subfertility risk with cyclophosphamide)
Mechanism of action
- An ester prodrug of the active agent mycophenolic acid (MPA)
- MPA non competitively and reversibly inhibits inosine monophosphate dehydrogenase (IMP‐DH), which catalyses a rate limiting step in the de novo synthesis pathway of purine nucleotides
- Lymphocytes are dependent on the de novo pathway
- MMF inhibits the proliferation of both B and T lymphocytes and decreases antibody production
What are the common adverse reactions of Mycophenolate mofetil (MMF)?
- GI: nausea, diarrhea, abdominal discomfort
- Haematological: leukopenia, anaemia, thrombocytopaenia
- Common and opportunistic infections e.g. Herpes Zoster, HSV, EBV, CMV, Tb, Hep B
- Teratogenicity
- Cancer risk (lymphoma, skin cancers) in post-transplant patients receiving MMF
What is the MOA and indications of Azathrioprine?
Uses: MAINTAIN Remission of SLE/CTD; and RA
Prodrug that is Converted to 6-mercaptopurine, inhibits de novo purine synthesis in lymphocytes
What are the common adverse effects of Azathrioprine?
Common adverse effects
- GI: nausea/vomiting
- Haematological: leukopaenia, pancytopenia
- Liver: hepatitis(AZT is hepatotoxic)
- Hair loss (which can also be an effect of SLE)
- Not teratogenic
ADR w ALLOPURINOL (dangerous myelotoxicity)
What is the MOA of ciclosporin?
Uses:
- Usually given to post-transplant patients
- AI Conditions – RA, psoriasis etc
Inhibits Ca-dependent T-cell signalling pathways by preventing Calcineurin Activation
- CsA first binds to Cyclophilin (cytoplasmic receptor) -> inhibits Calcineurin activation -> Prevents IL2 production
- IL2 is impt for T Cell proliferation -> hence inhibits T Cell activity
What are the common adverse reactions of ciclosporins?
- Hypertension
- ↑ K, Cr, uric acid
- Headache, nausea, vomiting, abdominal pain
- Tremors, hirsuitism, gum hypertrophy
What are the indications for IVIg?
- Refractory haemolytic anaemia, thrombocytopaenia
- Severe, active disease with major organ involvement
- Kawasaki
What is the MOA + indications of Rituximab?
- Anti-CD20 monoclonal Ab
- Mechanism of action: B cell depletion
- Indications: Induction of remission in refractory disease
What are the adverse reactions or Rituximab?
- Risk of infection with repeated course
- Hypogammaglobulinaemia
What are the side effects of NSAIDS and COX 2 inhibitors?
Non-Selective: Decreased risk for CV ents GI Side Effects (Dyspepsia, PUD, bleeds, perforation)
COX2 Selective (-coxibs): Increased risk of CV Side Effects (AMI, Strokes), decreased GI side effects
ALL NSAIDs: Nephrotoxic due to afferent VasoC! Hence C/I in renal impairment
NSAID Hypersensitivity 2 Main types: (TBL)
1) Pseudoallergy (pathophysio not well understood)
• Result of COX1 Inhibition, hence can be caused by MANY drugs
• Degree of COX1 inhibition = severity of Pseudoallergy
• Presents with Urticaria & Angioedema / Asthma / Both
2) Allergy (IgE Mediated)
• Elicited by a SINGLE NSAID
• A prior sensitization event w less severe symptoms
• Present similar to Pseudoallergy OR even anaphylaxis!
Always check for PUD, Reflux, Renal Insufficiency, Allergy before prescribing!
What are the side effects of glucocorticoids?
- Dermatologic: skin atrophy, acne, Cushingnoid appearance
- Ophthalmic: cataracts (posterior subcapsular)
- Renal: hypokalemia, hypertension (cross-reactivity w mineralocorticoid receptor)
- Endocrine/metabolic : hyperglycemia/DM
- Cardiac: ischaemic heart disease
- MSK: osteoporosis, hence can give calcium and vitamin D supplements, Avascular Necrosis of Hip,
- GI: gastrointestinal bleeding (esp. w concurrent NSAID use), give PPI cover
- ID: infections (due to immunosuppression)
What are the common side effects of DMARDs?
- BM Suppression (Myelotoxicity) -> Infection
- Hepatotoxicity
- GI S/E (can be very severe!)