Drugs for diabetes and epilepsy

Question 1

Uses for phenytoin

Answer 1

GEnralised, partial seizure
Status epilepticus
Trigeminal neuralgia
1b antiarrhythmic- be careful with dig

Question 2

MOA phenytoin

Answer 2

Binds to inactive or refractory NA channel after opening - most effective at those opening at a high frequency
Narrow therapeutic index

Question 3

Side effects of phenytoin?

Answer 3

Hirsutism
Gum hyperplasia
Acne
Coarse facies
Peripheral neuropathy
Megaloblastic anaemia

Question 4

Toxicity signs phenytoin?

Answer 4

Ataxia
nystagmus
paraesthesia
slurred speech

Question 5

Key points for phenytoin

Answer 5

Teratogenic
Enzyme inducer
90% protein bound
Liver metabolism
renal excretion
vit D deficiency
half life 24 hrs
Zero order kinnetics replace first order at high conc. dure to enzyme saturation

Question 6

Uses for valproate

Answer 6

partial, myoclonic, generalised seizures. ALso chronic pain

Question 7

MOA valproate

Answer 7

Stablises na channels and increases gaba concentration by inhibiting GABA transaminase

Question 8

S.E of valproate

Answer 8

Nausea, thrombocytopenia
HAir loss
GI
Neural tube defects’liver dysfunction

Question 9

Key points valproate

Answer 9

90% protein bound
liver metabolism
renal excretion

Question 10

How does gabapentin work

Answer 10

increases gaba synthesis in brain
Modulates voltage gated ca2 channels
Inhibits excitatory glutamate
increases 5-hr in cns

Question 11

Effects of insulin

Answer 11

INcreases:
-Glucose uptake into muscle and fat
-glycogen synthesis
-fat synthesis
-protein synthesis
-K+ uptake by cells

Decreases
-FAt breakdown
-Ketone synthesis
-Glycogen breakdown
-Protein breakdown
-Gluconeogenesis

Question 12

SUlphonylurea MOA?

Answer 12

INcreases insulin release
Decreases peripheral insulin resistance
Decreases glucagon secretion
Decreases hepatic insulinase activity

Question 13

Sulphonylureas key points

Answer 13

CAn cause hypos
80% bioavailability
Bound to albumin
Liver emtabolism
REnal excretion
Inhibited by thiazides, steroids + phenothiazines

Question 14

What type of drug is metformin?

Answer 14

Biguanide- two guanidine rings

Question 15

MOA metformin?

Answer 15

Decreases gluconeogenesis
Increases peripheral insulin utilisation
delays uptake from the gut

Question 16

Metformin key points

Answer 16

does not cause hypoglycaemia
60% bioavailability
unbound
excreted unchanged in urine, so caution in renal failure
can cause lactic acidosis