08 Drugs for eye and skin conditions

Question 1

8.01 GLAUCOMA EYEDROPS

Muscarinic agonists - pilocarpine

Answer 1

from the opposing end, antimuscarinic eye drops can worsen glaucoma

Question 2

8.01 GLAUCOMA EYEDROPS

Prostaglandin F2 analogues - latanoprost, bimatoprost

Answer 2

increases outflow of aqueous humour to reduce intraocular pressure

Question 3

8.01 GLAUCOMA EYEDROPS

Adrenergic agonists and antagonists - brimonidine, timolol

Answer 3

reduction in intraocular pressure can be achieved with α2-adrenergic agonists (brimonidine) or β-adrenergic antagonists (timolol)

Question 4

8.01 GLAUCOMA EYEDROPS

Carbonic anhydrase inhibitors - dorzolamide

Answer 4

decreases aqueous humour production
acetazolamide oral formulation is used as a diuretic and for mountain sickness

Question 5

8.02 VEGF INHIBITORS

Ranibizumab, aflibercept, bevacizumab - actions

Answer 5

reduces vasculogenesis and angiogenesis
decreases new vessel formation

Question 6

8.02 VEGF INHIBITORS

Ranibizumab, aflibercept, bevacizumab - MOA

Answer 6

inhibits vascular endothelial growth factor (VEGF), which is responsible for maintenance of vasculature and new vessel formation

Question 7

8.02 VEGF INHIBITORS

Ranibizumab, aflibercept, bevacizumab - abs/distrib/elim

Answer 7

given as intravitreal injections for neovascular pathology in the retina

Question 8

8.02 VEGF INHIBITORS

Ranibizumab, aflibercept, bevacizumab - clinical use

Answer 8

wet age-related macular degeneration
thrombosis of retinal vasculature
diabetic retinopathy

Question 9

8.02 VEGF INHIBITORS

Ranibizumab, aflibercept, bevacizumab - adverse effects

Answer 9

local ophthalmic complications from intravitreal injection

Question 10

8.03 RETINOIDS

Vitamin A derivatives: isotretinoin, adapalene, acitretin, tretinoin - actions

Answer 10

attenuate proliferative and inflammatory response
reduce sebaceous gland production

Question 11

8.03 RETINOIDS

Vitamin A derivatives: isotretinoin, adapalene, acitretin, tretinoin - MOA

Answer 11

bind to RXR (retinoid X receptor) and RAR (retinoic acid receptor) nuclear receptors to modulate epidermal cell growth and sebaceous gland activity

Question 12

8.03 RETINOIDS

Vitamin A derivatives: isotretinoin, adapalene, acitretin, tretinoin - abs/distrib/elim

Answer 12

given orally, variable bioavailability
topical tretinoin and adapalene for acne
large proportion bound to plasma proteins

Question 13

8.03 RETINOIDS

Vitamin A derivatives: isotretinoin, adapalene, acitretin, tretinoin - clinical use

Answer 13

acne (isotretinoin, adapalene)
psoriasis (acitretin)

Question 14

8.03 RETINOIDS

Vitamin A derivatives: isotretinoin, adapalene, acitretin, tretinoin - adverse effects

Answer 14

major risk of teratogenicity - restricted use and close monitoring is required
hypervitaminosis A - dry or inflamed mucosa

Question 15

8.04 TREATMENT OF PSORIASIS

Retinoids e.g. acitretin, alitretinoin

Answer 15

normalises epidermal cell differentiation and keratinisation

Question 16

8.04 TREATMENT OF PSORIASIS

Vitamin D analogues e.g. calcipotriol

Answer 16

applied topically to promote differentiation and suppress proliferation of keratinocytes

Question 17

8.04 TREATMENT OF PSORIASIS

Dithranol

Answer 17

mode of action unclear, but typically used in short-contact therapy where topical application is washed off after 1h

Question 18

8.04 TREATMENT OF PSORIASIS

Apremilast

Answer 18

anti-inflammatory effect through inhibition of phosphodiesterase 4

Question 19

8.04 TREATMENT OF PSORIASIS

Dimethyl fumarate

Answer 19

immunomodulatory effect
used in moderate to severe plaque psoriasis

Question 20

8.04 TREATMENT OF PSORIASIS

Monoclonal antibodies

Answer 20

diverse range of biopharmaceuticals used in psoriasis
e.g. adalimumab, ustekinumab, secukinumab

Question 21

8.05 SKIN PARASITES

Permethrin

Answer 21

single application
to be washed off 8-12h later
for treatment of scabies

Question 22

8.05 SKIN PARASITES

Crotamiton

Answer 22

applied once daily for 3-5 days
for treatment of scabies
can also be used for pruritus due to chickenpox, dermatitis, etc.

Question 23

8.05 SKIN PARASITES

Dimeticone

Answer 23

used for head lice
topical application to hair
washed off after 8h