Hydroxychloroquine

Question 1

What is HCQ?

Answer 1

An anti-malarial used as a anti-inflammatory in inflammatory conditions

Mechanism of action for this purpose is not well understood

Question 2

What is the dose of HCQ?

Answer 2

200mg - 400mg a day

Max dose is 5mg / kg

Question 3

What are the side effects of HCQ?

Answer 3

Ocular
- corneal deposits
—> mainly an issue for chloroquine rather than HCQ

• retinopathy
  —> occurs at daily dose > 5 mg/ kg
  —> occurs after duration of use > 5 years

Gastrointestinal side effects:
- flatulence
- vomiting
- diarrhoea

Cutaneous side effects
- pigmentation: grey - blue, 25% of patients on long term therapy
- urticaria
- lichenoid eruptions
- alopecia
- photosensitivity
- EAC
- achromotrichia
- itch
- exac. psoriasis

Neuropysch side effects (very rare)
- psychosis
- irritability
- depression
- insomnia
- nightmares
- seizures
- Tinnitus / vertigo

Neuromuscular
- proximal myopathy

Haemolysis
- in g6pd deficiency (rare - screening is not routine)

Question 4

Pregnancy classification of HCQ?

Answer 4

Category D

However
- used in neonatal lupus
- no evidence of congenital defects / still birth, prematurity, low birth weight, etc

Question 5

Common uses of HCQ in Derm?

Answer 5

Lupus
PCT

Dermatomyositis
PMLE
Sarcoidosis

Question 6

HCQ -
Pre-treatment investigations

Answer 6

Baseline eye check
FBC, UEC, LFTS, CMP

Question 7

HCQ
- monitoring Ix

Answer 7

Monthly FBC, UEC, LFTS for 3 months
Then 4-6 monthly
Eye checks annually after 5 years

Question 8

What are the cutaneous AE of HCQ?

Answer 8

Blue grey hyperpigmentation
- sun exposed areas

Hypersensitivity reaction
- lichenoid
- eczematoua
- urticaria
- SJS / TEN

Psoriasis (induced or exacerbated)

Transverse pigment bands on nails