PHARMACOLOGY questions Flashcards
How does RU-486 work?
It is an anti-progesterone & strong corticosteroid, so antagonises the maintenance of the uterine lining, and so maintenance of foetus is disrupted.
What is the normal dose for ethinyloestradiaol (EE) as an OCP? And in breast cancer?
OCP: 20-50µg. Breast cancer: 1-3mg.
What are the advantages & disadvantages of progesterone only contraception? What formulations/options are available?
Advantages: Use during breast feeding. Some formulations (implant & depot) offer long lasting effect. Used for those who can’t tolerate oestrogens.
Disadvantages: Irregular, break through bleeding. Some formulations (mini-pill) are less effective and need to be taken consistently. Thermogenic, weight gain, acne, decreased bone density.
Formulations: Mini pill, IM depot & implant
How do hormonal contraceptives work?
Main aim is to reduce chance of fertilisation and/or ovulation.
Normal menstrual cycle is 28 days. Day 1 is first day of bleeding. During this time, oestrogen increases to stimulate the proliferative phase of the endometrium. On day 12 there is an oestrogen surge, followed by a surge of LH on day 13, on day 14 there is ovulation. The corpus luteum then produces progesterone to maintain uterine lining. Oestrogen acts on the hypothalamic-anterior pituitary axis to inhibit FSH release, and LH release, which suppresses selection of a dominant follicle and reduces the chance of ovulation. Progesterone also reduces this axis as during pregnancy you don’t need to ovulate again, so both reduce chance of ovulation. Progesterone also increases the thickness of cervical mucus to prevent entry of sperm, and reduce chance of fertilisation.
Name at least THREE ways of taking insulin
- Injection/Syringe
- Pen/prefilled
- InnoLet (prefilled)
- Pump
What type of insulin is Insulin glargine?
Long acting (24 hours). Also a ‘basal’ insulin.
What type of insulin is Insulin Lispro
New, synthetic short/rapid acting (4-5 hours). Used as a ‘bolus’.
What is a mixed insulin, and describe it’s profile. Why/when would you use it?
Mixed insulin consists of a rapid/short acting insulin (such as lispro, aspart or gluisine) mixed with an intermediate acting insulin suspension (such as protophane or isophane suspension). Work for between 16-24 hours coverage, depending on mix.
It gives peaks when taken (due to short acting) with a tapering intermediate effect. It is useful for type two diabetics who are not confident taking insulin, as they get good post prandial coverage for breakfast and dinner, and the intermediate tapering provides some cover for lunch hyperglycaemia. Reduces risk of afternoon hypoglycaemia.
How long is the duration of action for detemire (Levemir)
12-20 hours (onset is 3-4 hours)
How quickly to short/rapid acting insulins work?
15 mins - 30 mins. Should eat very shortly after injecting. Work for 4-5 or 6-8 hours.
To which class do glibenclamide & gliclazide belong?
Sulphonylureas
How do sulphonylureas work?
Insulin secretagogue. They bind the a receptor associated with the K+ efflux channel on the Bcell of the pancreas and stop K+ leaving the cell.
Increased K+ –> Depolarisation –> opening of Ca2+ channel –> Ca2+ influx –> Phospholipase C –> IP3 –> Intracellular Ca2+ release from ER –> Release of insulin
What are the main side effects of sulphonylureas?
Hypoglycaemia & weight gain
What is the first line treatment for type II diabetes? Why?
Metformin (Biguaunide). Because it has been shown to reduce macrovascular mortality/morbidity (AMI, stroke etc) and microvascular complication (retinopathy, neuropathy and nephropathy)
Which drug lasses are considered ‘second line’ options for treating type II diabetes
Sulphonylureas, DPP4-inhibitors, glitazones, SGLT2 blockers, incretin mimetics
