Osteoarthitis And Gout

Question 1

What is the definition of Osteoarthiritis?

Answer 1

It is where all the structures of a joint have undergone pathological chages, often at the same time, resulting in joint failure.

Question 2

What is the role of cartilage in joints?

Answer 2

Cartilage is a thin layer of tissue between 2 bones lubricated by synovial fluid to provide a frictionless surface across which bones move.

Question 3

Name the 4 protecetive mechanism in the joint?

Answer 3

Joint capsule and ligaments, synovial fluid, ligaments with skin and tendons overlying the ligament, muscles and tendons that bridge the joint

Question 4

What is the summarized pathophysiology of osteoarthiritis.

Answer 4

Cartilage - shows splitting and damaged cartilage exposes proteoglycans and the negative charge attracts water (swelling occurs)
Bone - osteophytes form at the margin of the joint near the area of cartilage loss. Osteophytes are an NB indicator of OA
Synovium - becomes inflamed and oedematous

Question 5

What are some clinical presentations of OA?

Answer 5

Pain becomes more progressive, more troublesome at night, stiffness occurs. And also weakness.

Question 6

What are some treatment plans for OA?

Answer 6

Step 1: Paracetamol
Step 2: NSAIDs - topical or oral
Step 3: Tramadol, corticosteroids injection into the joint. And Hyaluronic acid, 3 to 5 injections weekly.

Question 7

Where is uric acid synthesized?

Answer 7

Mainly in the liver

Question 8

What are the clinical features of gout?

Answer 8

Overproduction and underexcretion of uric acid

Question 9

How is uric acid formed?

Answer 9

Nucleic acids–> Purines–>Hypoxanthine–>Xanthine (Xanthine oxidase) Uric acid–> renal excretion

Question 10

What are some signs and symptoms of gout?

Answer 10

Fever, Intense pain, erythema, warmth, elevated serum uric acid

Question 11

Why is aspirin not given in gout?

Answer 11

Because it may cause gouty arthritis.

Question 12

What is the MOA of colchicine?

Answer 12

Antimitotic effect - stops cell division in the GI
Inhibits the release of histamine from mast cells
May alter neutrophil motility

Question 13

What are some common adverse effects of colchicine?

Answer 13

Nausea, diarrhoea, vomiting, abdominal pain

Question 14

List 4 drug interactions of colch?

Answer 14

NSAIDs, CYP3A4 inhibitors, Warfarin, Alcohol

Question 15

What is the MOA of Allopurinol?

Answer 15

Its a xanthine oxidase inhibitor. It will decrease the formation of xanthine from hypoxanthine, which will decrease levels of uric acid

Question 16

What are some contraindications and DIs of allopurinol?

Answer 16

Acute gout, pregnancy and breast feeding. Amoxicillin (skin rash)
Thiazides - increase alloxanthine concentration

Question 17

What is the MOA of probenecid?

Answer 17

Uric acid is secreted into the proximal tubules via OAT1 and 3 transporters. Once in the urine, it is actively reabsorbed via the URAT transporter. It blocks the URAT transporter and the OAT1 and 3.