Dermatopharmacology Flashcards
H1 antagonists
1st generation: diphenhydramine, promethazine, chlorpheniramine, hydroxyzine 2nd generation: Fexofenadine, Loratidine, Cetirizine, Desloratidine
H2 antagonists
ranitidine cimetidine
Doxepin Side Effects Black Box Warning
TCA that blocks H1 and H2 Sedation, Decreased seizure threshold Not with other anti-depressants Black Box: Suicidality
Most abundant Retinoid receptors in skin
RAR-y and RXR-a
Medication contraindicated if history of cutaneous lymphoma
cyclosporine risk of progression
Random cyclosporine side effects
hypertrichosis, gingival hyperplasia, tremors, paresthesia, hyperuricemia (gout)
Creatinine increase on cyclosporine
if > 30% , decrease dose by 1 mg/kg; If > 50% then stop; can resume at a lower dose
Steroids with high mineralocorticoid
Hydrocortisone Cortisone Short-acting Less glucocorticoid effect
Steroid Glucocorticoid> mineralocorticoid
Prednisone Prednisolone Methylprednisolone Triamcinolone
Only glucocorticoid
Dexamethasone (long acting) Betamethasone Methylprednisolone (medium acting) Triamcinolone
11B-hydroxysteroid dehydrogenase
Converts steroids to active form in liver Cortisone -> cortisol Prednisone -> prednisolone
Every other day dosing of steroids decreases which side effects
Hpa axis suppression Opportunistic infections Growth suppression Does not lower risk of cataract or osteoporosis
Steroid pregnancy category
Pregnancy category C
Half life of isotretinoin
20 hours
Half life of etretinate
120 days
Half life of acitretin
2 days
Triglyceride level above which you should stop an oral retinoid
TAG> 800
Bexarotene should not be used with which medication? why?
Gemfibrozil (CYP 3A 4 inhibitor), increases levels of bexarotene
Tretinoin receptor
RAR
Alitretinoin receptor
RAR and RXR
Adapalene receptor
RAR- B/y> a
Tazarotene
RAR-By>a Pregnancy category X
Bexarotene
RXR Pregnancy category X
Bexarotene Side effects
Central hypothyroidism Neutropenia, Leukopenia
Isotretinoin receptor
None
Etretinate receptor
None
Acitretin receptor
None
Corticosteroids MOA
Decreased: NFKB, eicosanoids Increased: IL-10 (down regulates TH1, and other cell mediated immunity), increases apoptosis of eosinophils and lymphocytes
Risk factors for HPA axis suppression with corticosteroids
Divided dosing (But more effective for relief) Abrupt cessation Major Stressor
Types of Exogenous Adrenal Insufficiency
Steroid Withdrawal Syndrome (arthralgias, myalfias, anorexia; can have normal cortisol levels) Adrenal Crisis (+ Hypotension)
Apremilast
PDE Inhibitor
Tofacitinib
JAK 1, 3 inhibitor SE: URI, headaches, nausea
Ruxolitinib
JAK 1, 2 inhibitor
Azathioprine MOA
Purine analog, inhibits purine metabolism and cell division HGPRT metabolizes into active form (6=TG)? TMPT inactivates, Xanthine Oxidase Also
Azathioprine SE
SCC! GI: most common Hypersensitivity syndrome Risk of hepatosplenic T-cell lymphoma (when used with TNF-a) Pregnancy category D
Cyclosporine MOA
Binds to cyclophinin, the complex then binds to and Inhibits calcineurin. When calcineurin is inactive, NFAT does not get dephosphorylated (stays inactive), and IL-2 among other things are not transcribed
Cyclosporine dosing
2.5-5 mg/kg
Drug of Choice for HTN related to cyclosporine
CCB
Methotrexate MOA
binds dihydrofolate reductase, prevents conversion of dihydrofolate to tetrahydrofolate
(this inhibits/stops purine synthesis)
What does Folate help with when on MTX
GI adverse effects
less risk of LFT elevations (76%)
less risk of pancytopenia
Methotrexate and the liver
> 1.5-4 g may need testing
Liver biopsy is gold standard
Methotrexate and pregnancy
Category X
Other methotrexate side effects
acute pneumonitis, pulmonary fibrosis
pancytopenia (within 4-6 weeks)
phototoxicity (radiation recall)
Medications to avoid with methotrexate
trimethoprim
sulfonamides
dapsone
(tetracyclines, phenytoin, phenothiazines, sulfonamides, NSAIDs, salicylates)
Treatment for MTX toxicity
Leucovorin (folinic acid)
Mycophenolate Mofetil MOA
inhibits inosine monophosphate dehydrogenase
(inhibits de novo synthesis of purines)
Hydroxyurea MOA
inhibits ribonucelotide diphosphate reductase (impaired DNA synthesis)
Hydroxyurea SE
Megaloblastic Anemia
DM-like eruption
Leg ulcers
Hyperpigmentation of skin and nails
Cyclophosphamide MOA
alkylating agent (aka damages DNA via crosslinking)
Cyclophosphamide side effects
hemorrhagic cystitis (acrolein, metabolite)
transitional cell carcinoma of the bladder
premature ovarian failure
anagen effluvium
hyperpigmentation of hair and nails
Chlorambucil MOA
Side Effects
alkylatine agent (damaged DNA via cross linking)
Allergy to nitrogen mustard is a contraindication
Antimalarial MOA
Inhibits UV induced cutaneous reactions, suppresion of superoxide formation
decreases expression of MHC complex antigens
Reduces lysosomal size and impairs chemotaxis
Inhibits plt aggregation and adhesion
Chloroquine side effects
contraindications
psoriasis exacerbation
GI side effects
agranulocytosis
Contraindications:
myasthenia gravis
Ocular Side Effects
Antimalarials
keratopathy, retinopathy (not reversible)
Quinacrine does not have ocular toxicity
Skin Pigmentation
Antimalarials
blue/gray on shins (> 4 months therapy)
Nail hyperpigmentation
yellow pigment-> quinacrine
Dapsone MOA
inhibits myeloperoxidase
FDA approved for DH and leprosy
DH and bullous SLE respond within 24-36 hours
Dapsone SE
MOA: myeloperoxidase and inhibits bacterial synthesis of dihydrofolic acid, via competition with para-aminobenzoate for the active site of dihydropteroate synthase
hemolytic anemia
methemoglobinemia
agranulocytosis: idiosyncratic (btw 3-12 weeks)
distal motor neuropathy
Cimetidine and Vitamin E decrease risk of methemoglobinemia without decreasing efficacy
Etanercept
Fusion protein
Binds both TNF-a and TNF-B
Infliximab
Chimeric monoclonal IgG to TNF-a only
Adalimumab
Fully human monoclonal IgG TNF receptor
Etanercept, Infliximab, Adalimumab
Pregnancy Category
B
Infliximab associated anti-drug antibodies
Increase risk of infusion reactions
form before week 24
decreased efficacy of drug
MTX may help
Not seen with Etanercept!!!
TNF factoids and side effects
Injection Site Reactions Common (Etanercept> adalinumab)
CHF (Infliximab)
Demyelinating disorder (Don’t use any if FHx)
Drug induced SLE: rare, resolves after cessation
Can use in Hepatitis C infection??
Ustekinumab MOA
Fully human monoclonal IgG1
to p40 subunit (IL-12, IL-23)
Ustekinumab SE
URI
Reversible posterior leukoencephalopathy (PRES)
Rituximab
Chimeric monoclonal antibody to CD20
Depletion within 2-3 weeks, sustained for 6 months
Pregnancy Category C
Progressive Multifocal Leukoencephalopathy